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Royal Enfield Unit Construction(UCE) Engine vs Royal Enfield Cast Iron (CI) Engine!

Every other day, I answer comments on ICB where people eager to get onto the Royal Enfield bandwagon have one question that never seems to go away. Which is better, Royal Enfield Unit Construction Engine or the Royal Enfield Cast Iron Engine? Now, here’s the answer, it is the Unit Construction Engine that is better. Period. And If you really are interested to know why it is so, you must read ahead.

2011 Royal Enfield UCE500 Classic Chrome

2011 Royal Enfield UCE500 Classic Chrome

Here’s a quick comparison and if you really want to understand more about the intricacies of the different Royal engines, you need to read the post below this comparison. However, for a quick comparo, click on the images to enlarge.

Royal Enfield Unit Construction UCE Engine Advantages

Royal Enfield Unit Construction UCE Engine Advantages

Royal Enfield Unit Construction UCE Engine Advantages

Royal Enfield Unit Construction UCE Engine Advantages

I own, rather owned a 2009 Royal Enfield Bullet Machismo 500LB which I bought mainly because of it being the most powerful Royal Enfields around at that time and age. I also bought the AVL engined Bullet because it was better than the cast iron engine in terms of reliability as well as performance. In due time, I began working on my Bullet on my own. But the 500cc AVL Lean Burn still required a lot of maintenance, especially if ridden hard. So, here is Royal Enfield’s latest solution, the Unit Construction Engine.

First of all let me explain what the UCE is all about. Previously, the Bullets, both cast iron engine and AVL LB engines used to come with three parts put together, called the Pre-Unit Construction Engine. The engine, gearbox and clutch cases were three different units altogether connected to each other independently. So what happened was you needed to change oil at three places each time. Now, that is a messy thing to do, and also considering the various gaskets that required replacement frequently, in simple terms, it was maintenance heavy.

Also, since the engine was separate from the gearbox and the clutch, a lot of power used to get lost in terms of transmission losses as the set up is not as efficient as modern engines. so, not only were the Cast Iron and AVL LB Bullets delivering lesser mileage but they were also making lesser power at the rear wheel even though they were making decent power at the crank shaft. Here are some figures. The Cast Iron and AVL 350cc engines both produced 18 Bhp at the crank, but this figure went down to 12 Bhp at the rear wheel. Power loss: A whopping 33%. Culprit: Transmission losses.

Now, the UCE 350cc engine produces about 19.8 Bhp at the crank shaft. At the rear wheel, the power is about 16 Bhp. So, that is only 20% power lost in transmission losses, which while still a lot in terms of modern motorcycles, is fair enough for a Royal Enfield, which is a low revving, big single. Also, the Unit Construction Engine is more fuel efficient than both the Cast Iron and AVL Lean Burn engine by almost 20%. While the 350cc CI and AVL engines used to deliver 35 kmpl, the UCE engine consistently returns 45 kmpl.

Unit Construction Engined Royal Enfield Classic 500 Military

Unit Construction Engined Royal Enfield Classic 500 Military

Now, let’s look at why I’m rating the UCE engine higher than the CI or AVL engine. First of all, let’s begin with the valve train. The UCE engine now uses hydraulic valve lifters(tappets) to instead of the conventional tappet arrangement. What happens in the UCE engine is, pressurized oil drives the pushrods in the engine. Due to the oil pressure being able to remain constant for long periods of time, the pushrods don’t cause the valve clearances to change like they used to in the older engines. So, you get more consistent performance. In other words, riding hard won’t make your valves loose anymore.

While I wouldn’t call the hydraulic tappets totally maintenance free, for street riding purposes they should do fine for at least 20,000 kilometers before needing any kind of attention. Coming to the Cast Iron and AVL engines, which use solid tappets to move the pushrods, very often the pushrods become loose thus requiring constant adjustment. So, you would have seen many Bulleeteers constantly running to their mechanics to get their “tappets adjusted”. So, not for nothing they said that the mechanic is the Bullet’s and the Bulleteer’s best friend. ;-)

The third big change in the UCE engine is that of longevity. The UCE engine will last longer than the Cast Iron as well as the AVL engine even if you ride hard. Here’s exactly why. Ask a Bulleteer who rides hard about how long his Cast iron Bullet will last at 120 kph. Chances are that he would say that he doesn’t even dare taking his Bullet to those speeds. Let’s find out why. The Cast Iron Bullets used to come with a floating bush big end. The floating bush worked well until it was immersed in oil and there was enough flow. Yes, flow, rather oil flow is the big buzzword here.

In, Cast Iron Bullets, piston type oil pumps were used. These oil pumps circulated about 1 liter of oil per minute at 5,500 rpm which is almost half the Bullet’s oil capacity. Now, at 5500 rpm, when the engine is revving at it’s very top, just 1 liter of oil circulating to cool down the engine means only one thing. Bad engine cooling. Oil, as you must be aware is the blood of the engine. Apart from lubrication, more importantly it helps keeping the engine cool by absorbing heat off the metal parts unto itself and then circulating it continuously to dissipate heat.

Cast Iron Engined Royal Enfield STD350

Cast Iron Engined Royal Enfield STD350

On the cast iron engines, which were designed in the 1950s, this simply does not happen efficiently enough. To be fair, speeds in the 50s and 60s were quite low as roads weren’t as well developed as they are now. The Bullet, back then was a decent ride but the Cast Iron engine has simply outlived it’s purpose. Brutal it may sound, but that is the truth. Royal Enfield attempted to make some amends in the late nineties when they headed to Austrian engine design firm, AVL. AVL gave birth to the AVL range of engines, whose biggest advantages were a better oil pump and a roller type big end bearing.

The AVL engines featured a gear driven oil pump which used to pump double the oil per minute when compared to the Cast Iron engine at 2.42 liters at 5,500 rpm. So, more oil being circulated means that the heat is being dissipated better. Also, the roller end bearings work better than the floating bush. The other big change was the aluminum block which, being the biggest advantage of the AVL engine also forced the engine to be the least popular. While Aluminum dissipates heat better, it also muffles less sound. So, the AVL engines were prone to valve train clatter.

This is one reason why a lot of Royal Enfield enthusiasts sill preferred the cast iron engine for it’s soulful thump even though the AVL engine was vastly superior to the cast iron engine. Now, think about this,  if you would prefer thumping at 40 kph all day on a highway, you may still prefer the Cast Iron engine. For everything else, the AVL engine is better. But then again, the AVL engine is still inferior to the latest kid in town, the UCE engine as the UCE engine has improved valve train apart from a lot of other improvements too.

AVL Engined Royal Enfield Machismo 350

AVL Engined Royal Enfield Machismo 350

For starters, the UCE engine uses a rotary type oil pump which pumps our 9.5 liters of oil ever minute at 5,500 rpm. This is full four times more than the AVL engine and a whopping 9 times more than the 9 times than the cast iron engine. Obviously, if you’ve gotten till here, you’ll know how increased oil circulation will improve the longevity of the engine. For the record, my good friend Adrian’s 2008 Thunderbird UCE350 has managed to run strongly even after 60,000 kilometers with absolutely no repair work done to the engine thus far.

YouTube Preview Image

Just take a look at the sheer volume of oil being pumped in the UCE engine, which is many times more than the Cast Iron or the AVL engine could ever manage.

Also, the UCE engine comes with a anti-backlash system engineered into the cams which makes sure that the cam backlash is kept to the bare minimum, which increases the cam life as well as maintains consistent engine performance even under hard riding. Bulleteers will understand how frustrating backlash can be on Cast Iron and AVL engined bullets, which though featuring adjustable cam spindles were still troublesome if ridden at speeds of 80 kph and above frequently. Also, the UCE engine has a piston ring designs that eliminates blow by.

Getting into crankcase blow by is another topic for another day. So, you must understand that a lower blow by means lesser oil getting wasted or lower crank case pressures. Two more changes are an auto decompressor assembly that sits on the UCE engine’s exhaust cam that makes starting easier. The UCE Bullet is almost as easy to start as say a Karizma or a Unicorn and now, that is a huge change, isn’t it? Finally, the UCE engine also has an auto primary chain tensioner which makes sure that the primary chain has just enough tension to ensure best performance and least maintenance.

If you’ve read this much, first of all I thank you for your patience. I also am sure that armed with so much more knowledge about Unit Construction Engine Bullets, you can now confidently choose as to which Royal Enfield suits you, either a new one or a used one. Also, the future clearly belongs to the Unit Construction Engine and in due course of time, spare parts for the Cast Iron and AVL engines will begin to dry up. In fact, parts for the AVL engine and the CI500 engine are already scarce.

Well, the thump obviously will be muffled in the long stroke UCE engine, which still remains a big, low revving single true to Royal Enfield’s heritage and is not quite an appliance bike like say the Pulsar or the Unicorn. And before I go, remember, Royal Enfield themselves offer a 40,000 kilometer/two year warranty on the UCE bullets while they used to offer only 10,000 km/1 year warranty on the Cast iron and AVL engines. So, that itself says a lot about how much the manufacturer  trusts the UCE over the CI and AVL engines, doesn’t it? So, choose wisely and yes, Happy Thumping!

Comments

115 Responses to “Royal Enfield Unit Construction(UCE) Engine vs Royal Enfield Cast Iron (CI) Engine!”

  1. Rohan on April 5th, 2011 10:24 pm

    Excellent post my man! I’m buying UCE anyways…a tad bit sad that I wont need to open her up too often.

  2. Jay Prashanth on April 5th, 2011 10:34 pm

    Glad you understand dude. Lotsa folks are getting stuck up with the thump thingy and they don’t realize the hassles of it all. A vintage bike is just that, vintage.

    Meanwhile, here’s something that’s even more interesting, Read this->http://www.indiancarsbikes.in/motorcycles/royal-enfields-uce500-engine-dump-fuel-injection-carburetted-icb-exclusive-34230/

    Cheers,

    Jay

  3. krishna on April 6th, 2011 1:37 am

    awesome post bro hope it opens some eyes who still wanna stick to CI….i have TBTS and it offer only 1 year warranty nt two…

  4. Potha on April 6th, 2011 4:49 pm

    Thanks Jay,

    It was very informative read. Please do keep posting these type of technical articles.

    What do you think about RE going back to Carb, it looks like we are being short changed instead of offering kits to upgrade to O2 set up?

  5. Jay Prashanth on April 6th, 2011 5:19 pm

    Potha,

    As you know Royal Enfield should have offered the o2 sensor in the FI system right from the beginning. Since they wanted to keep costs low, they refrained from doing so. As you say, Royal Enfield as a goodwill measure should offer the o2 sensor kit for existing customers if at all they are really serious about satisfying their customers. But in India, unfortunately very few manufacturers really bother about a satisfied customer. Any which ways, the carbed UCE500 is not yet a certainty even though the RTO shows an entry. Also, it may not be offered on the Classic and instead the Machismo might get the carbed UCE500. So, I won’t comment on that, just as yet. We’ll keep you updated as and when we receive any information regarding the carbed UCE500.

    Cheers,

    Jay

  6. Satyabrata Sarkar on June 18th, 2011 4:35 pm

    Hi,
    I own a enfield classic -350(1995).I argee with you that the UCE is much more advance and much more better than the old cast engine.Also the availability of spare is tough. But then also I personally feel that enfield is not for riding at 100 or 110 kmph, because enfield is like a elephant which doesn’t care about anything but goes on slowly on its defined path. Also the main identity of enfield is its vibration and sound which has been reduced in the newer versions.I have tried the new enfield of one of my friend, but I didn’t get the same feelings as of my own enfield. There is no much difference in new enfield and Karizma or Pulsar 220.Although this all are my personal views, I don’t know how many people will agree with these thing or not.

  7. roshy n j on June 23rd, 2011 4:58 pm

    i trusts the UCE

  8. Raghav on July 20th, 2011 11:07 pm

    Hi Jay,

    That was a very informative & outstanding post i have read so far.

    Have booked a bullet 350cc uce, expecting delivery by the end of this month or early next month.

    All these days i was very skeptical about the transformation of RE from ci, avl to uce but now after reading your post, i must say that am relieved & breathing easy to book a uce rather than ci or avl, yes the thump is quite different & missing but other updated technology & advancements have been matched up to the standards & have made it hassle free

    Thanks for that eye opening post

    Keep it up buddy :-)

    Raghav

  9. Mahesh on August 14th, 2011 3:47 am

    nice article,find it very helpful.Thank You

  10. Vado on September 15th, 2011 11:17 pm

    Hi,
    I have Bullet 350 for the last 5 years (with old CI engine). I love the bike for the thump and heavy weight and comfortable riding too… It is definitely a gorgeous and cult bike to have! I can’t even call Karizma or Unicorn a bike compared to Bullet! But.. I must admit that maintenance costs are quite high. Also I have 4-5 major or moderate issues every year when I need to get bike into service. Say, this year – clotch plates gone, low decompression, spark-plug thread gone… I’ m not even mentioning here countless brakes and clotch adjustments, oil leakages, very low mileage (25-30 km/l).
    So in few days I’m buying new Bullet Electra 350 with UCE. I’m feeling it is time to change. It is still Enfield Bullet after all.
    But I know that I will surely miss my old Bullet like an ex-girlfriend that I loved much but who was causing me too much troubles…
    Peace!

  11. vikky on October 31st, 2011 4:37 pm

    Jay Prasanth… I doubt how well will UCE stand the test of time as CI did.. lets wait n watch but i bow to you for a such an insightful review.. God bless you Man!! Bullets’s unique identity was it’s THUMP which made heads turn n could hear it from far distance that ya a bullet is going somewhere around us But yes Truth is always bitter.. New UCE makes one feel like its kind of Japanese bike with Bullet outfits.. But i do care for environment and better sake of RE to continue on its production to next decade or else Govt will shut it down as it happened to YEZDI.. I am using and proud owner of 1994 model cast iron bullet but soon going to shift to newer bullet with UCE n Thanks to you for changing my perception..

  12. Jay Prashanth on October 31st, 2011 4:59 pm

    Vikram,

    Thank you for the kind words. Glad you’re shifting to the UCE but I hope you’ll keep your CI350, cos you’ve got a classic there. Happy thumping!

    Cheers,

    Jay

  13. vikky on October 31st, 2011 6:50 pm

    Jay,

    Thanks but for a middle class man it’s hard to keep a collection of Royal Enfield.. I will probably get a good thumping silencer for a new 350UCE to pacify. So it’s nature’s rule.. old one has to give way for the New ones.. But my Love for the Old Classic 350cc for its robustness n thumping will never diminish & will never be replaced by any bike.. Happy Thuming to you dude!!

  14. Lakshminarayan Kashyap on January 6th, 2012 8:30 pm

    Thanks man. An awesome post. Wanted to know the real facts about RE motorcycle engines. I think I know better now and clearer than I knew the engines before.

    Though, I am planning on the new Thunderbird 500cc released yesterday in New Delhi at the Auto Expo 2012. Impressed with the Fuel Injected engines of my friend’s Classic 500. Plus projector headlamps, disc brakes on both brakes, etc, I really think it’ll be in demand far more than any other competitor.

    Long live RE !! :)

  15. Aditya on January 22nd, 2012 1:08 pm

    The best and the ultimate comparison between engines used in RE motorcycles. Reading this comparison helped me make the final decision of buying a UCE powered RE motorcycle and made me a regular here at Indiancarsbikes.in. In the comparison above, it has been indicated that RE offers 2 years of warranty on UCE motorcycles, but sadly it is not the case in India. Unlike some countries in the West where they get 2 years of warranty, here in India we have only 1 year warranty on all RE motorcycles.

  16. Hitesh Sharma on January 24th, 2012 12:27 am

    Thanks for such a wonderful and informative article.
    i already booked RE Classic 350 two weeks back but was still in doubt till reading this article on whether to go for new uce or the old cast iron engine model i.e. used bullet. googling for the same got me here and now after reading this article i am clear about the technical differences and will definitely be going for new UCE model.
    Regards

  17. John on January 31st, 2012 1:57 pm

    Good article there Jay, thanks for sharing the technical aspects and the advantages of UCE Engine. I’ve had a 1978 model for the last 12 years and have just got rid of it, looking forward to riding the UCE.
    Lets just say ive traded in the white elephant :-))
    /S/

  18. harshad on February 3rd, 2012 12:45 pm

    Jay,
    That was awesome review man. I was in dilemma whether to buy new bullet or not. I was looking for insight on CIs and UCEs and after reading your post I am relived and all my doubts are cleared. You rock. Booked Electra twinspark UCE.

  19. Will Barclay on February 4th, 2012 4:26 pm

    Sorry, I still want the real, cast iron engine. Lets go through the supposed advantages of the UCE:
    1. OIL FLOW – My Cast Iron Engine has a high capacity bronze oil pump for more than double the oil flow than the engine was originally designed for. Advantage negated.
    2. HYDRAULIC TAPPETS – This is the one thing that I wish the Cast Iron Engine had and is perhaps the only true advantage of the new engine. I do enjoy setting my own valve clearance though and anyone who does not should probably not be riding Bullets at all.
    3. Economy / Efficiency: My Cast Iron engine has been fitted with mixture control that allows the rider to adjust the fuel/air mixture while on the move. this allows the rider to use the amount of fuel appropriate to the situation resulting in better power and cooling when required and better economy when available, just like a light aircraft. RESULT: My cast iron engine gets better fuel economy than the new engines when operating in the real world!
    4. CYLINDER BARREL: My “Cast Iron Engine” uses an aluminum alloy barrel as well leaving no advantage here for the new engines.
    5. DECOMPRESSOR: I never had a use for the decompressor and so use that hole in the head of my Cast Iron Engine for another spark plug with an independent ignition system (with its own coil). RESULT: Easier starting, better economy, more power, and a redundant system more reliable than the new electronic ignition.
    6. ADJUSTABLE CAM SPINDLE: Not a factor
    7. The roller bearing I have fitted to my crankshaft means that it is happy to go 120kph (or much faster) all day long. The new engines cannot keep up.
    8. I am producing about 48hp at the crankshaft and losing a lot in the inefficient gearbox, but I still bring a lot more power to the road than anything now coming out of the factory. and I do it reliably, using less fuel, on a motorcycle much more true to its heritage and to the reason that we ride Bullets. I would never ride a Pulsar, but I would rather ride that than a new “imitation” bullet.

  20. Dheeraj Rinwa on March 10th, 2012 12:16 pm

    A very insightful, informative post. Thankx it made me a much knowledgeable man and helped me in making my decision.
    Cheers

  21. HS on March 12th, 2012 5:53 pm

    Pls refer above (Hitesh Sharma on January 24th, 2012 12:27 am)

    Even though i had booked Classic 350 (uce engine) but after 2 months of study, research and interaction with users, mechanics and experts i came to following conclusion:
    1. the new one is like any other bike and not a real royal enfield bullet.
    2. the beauty of cast iron engine bullet is that its comparatively simple and with little bit of training we can do troubleshooting and repair it on our own (a “do it yourself” kind bike).
    there must be some beauty which made this technology to exist in market for more then 50 yrs without any major technical changes.
    3. there is no need to compare the real RE bullet (CI Engine) with the present one. uce is a good bike with 35 to 40 kmpl mileage but its not RE bullet in real sense.
    So i will be going with Royal Enfield Bullet Std.350cc (cast iron engine).
    Hitesh Sharma

  22. Sanket on March 13th, 2012 9:11 pm

    @ Rohan – Best of luck and I hope you don’t have to open up an UCE coz if you do then the labor charge will be atleast 5x more than old Enfields.

    @ Jay – People buy Classic (I mean real classics here)/Vintage bikes NOT for speed or initial pickup or mileage. They buy it because the so called “Charm” of it attracts them. But these days there are alt options. UCE is one of them. It’s not bad, it’s faster, its more fuel efficient but it’s not a classic, neither has an engine from post WWII layout type, lacks the feel but its good ;)

    @ Krishna – If you love it then stick to it.

    @ Potha – Carb is any time any day better than EFI – Especially when it comes to performance. For people who want mileage, yes they prefer EFI. Also, less headache.
    @ Satyabrata – You can’t actually say that UCE is better than CI. They have their own pros and cons. Also, older Enfield’s engine had the vibrations, newer UCE’s engine? I don’t know but the entire bike vibrates after 90~110 range. I couldn’t see anything in the rear view mirror lol.

    @ Vikki – +1, that’s all I gotta say. And yes, let’s not do some crap talkin about the CI because they ruled for 50 friggin years ;)

    @ Will –

    UCE – 0
    Will – 1

    :D

    @ HS – Agreed

  23. harshad on March 16th, 2012 12:13 am

    Dear all,
    Be open to embrace new technologies. Now, folks who have got old bullets will never deny it’s disadvantages. It is nothing but natural human tendency. How can you expect the things to remain same as they were 20-30 years ago. Everything changes with time. Even today’s UCE will be replaced by some other engine which will be surely cursed by this generation and appreciated by the future generation. As mentioned earlier, it is just human nature.

  24. Sasank on March 23rd, 2012 4:59 pm

    Its the most informative article no doubt about it. I visited many sites for Thunderbird review but all I read was ‘bla my oil leaks… worst bike.. don’t buy and other negative comments’ from noobs. Good to read an article from a man who knows how RE engine is built. Thanks a million! Bookmarked the website.

  25. Sanket on March 26th, 2012 5:04 am

    @ Sasank – Ignore the haters mate. You know what? People say cast irons are oilfields lol. I had 3 cast irons and 2 avls engines so far in these 12years. Trust me! none had oil leaks! One must know how to maintain a bull! its not easy, not impossible either :)

    Happy Thumping!

    Oh yea! When they failin to tame their bulls!! They start hatin !! :D

  26. Ryan John on March 26th, 2012 1:37 pm

    jay i think youre crazy brah CAST IRON BULLETS RULE!!! FK U AND YOURE UCE BS!!! HAHAHA***

  27. Sanket on March 28th, 2012 10:33 pm

    Ryan – Bro, lets not start a virtual fist fight here.

    Look we got 3 different breeds here? CI, AVL and UCE. Now they have their own pros and cons. A jetted , properly carbed 500 can beat any AVL or UCE but once again! That performance comes with a cost. The whole purpose of AVL or UCE is not mileage but overall efficiency. Also, Royal Enfield was in a bad shape for several reasons. Their products not meeting the requirement, emission norm related stuff and what not. So they had to make something advanced. Doesn’t mean that they killed the Cast Irons. That is why the parts are still available in market for all version. Also, I am a proud CI rider, from past 10 years I have rode CI’s and recently bough an AVL 500. Frankly speaking, anything and everything that is not CI – is not a real bullet. That’s how it goes but everyone wants to try these mean machines! So to make this more user friendly, AVL and UCEs were made. OFC Avl and UCE doesn’t have the charm but its easy to ride. That’s why leno said that UCE is nice but its something like a level above advanced scooters! Where as the CI’s are vintage and can be transformed into retro shapes a sizes. Like the Scramblers, Bobbers, Kneesliders, Cafe Racers. OK! I Think I will stop my spam here… Once and for all! This is related to RE, a typical ride rode by typically retro people :)

    -San

  28. Sandy on April 3rd, 2012 11:57 am

    Hey Jay, Nice article.. but…now u have confused me ….. i love the bull just for its thump and the gear style…in new bulls u don’t get that old gear style(right foot gear with the small neutral lever)…that is unique in bullets which no other bikes have…plz suggest
    -sandy

  29. John on April 10th, 2012 1:30 am

    I have used Old bullet CI 1996 model.

    Pros:-
    1)After I started using this, my respect got increased in my area automatically.
    2) When ride it everyone eyes falled into it
    3) Sound will give you Good feeling when ride it.
    4) I have altered with Classic spring, hence no back pain on it

    Cons:-
    1)Untill going fine, U will feel like a King, once it Start give prob then U will feel urself as cursed person.

    2)I have faced below simple problems, but Lost my whole energy and Money on it:-

    a) Accelator cable cut:- No where I found accelator cable for bullet in Nungambakkam, I caught auto and bought
    cable from Royapet. Nearly 15kms distance. But Cable which I bought was duplicate. Approximately Mechanic put it.
    Before Reached my destination 10kms distance, Bullet stopped for every 100mts once and need atleast 50kicks to start
    it, due to this my knee got started pain and my heart tooo. Note:- Cable rate is only Rs 40, but auto charged Rs :-200

    b) at very first day my bullet got puctured at 6am in Egmore, no Valcanizer or Normal mechanic didnt to help me, even nearly
    I have begged them. I was waited in mechanic shop for 3hours after then mechanic sent his helper to help me.
    For this I have spent to get mechanic , auto charge is Rs 300. Due to no mechanic willing to help, I have went
    to all mechanic shop and home nearby Egmore.

    c) Again one day my Bull got punctured in my home itself, By filled air in punctured Typre in nearby mechanic shop
    and reached Valcanizing shop. For single puncture he asked me Rs:-60.

    d) In Traffic, bull without self start really horrible thing to ride it.

    e) Bullet will start within a single press some days and also it wont start even so many kicks most of a time.
    It need to visit mechanic frequenctly for starting problem and also due to Bullet mechanic demand, no
    Bullet mechanic will respect you as a man. You need to stand or wait like a student in front of Headmasters.

    f) If you ride it beyond 45kmph or 50kmph suddenly mileage will be 25kmpl or 20kmpl. you cannot
    overtake any vehicles. If you follow speed 40kmph, you will get mileage 35kmpl. you can’t expect pickup init.

    Conclusions:- If you want to own Old Bullet, you Must need following:-
    1) You should have more time to spend on it
    2) You should keep money at all time, atleast 1000rs
    3) you should check and change below:-
    TYRES,TUBES,CARBURATOR,ACCELATOR CABLE(keep one spare),CLUTCH CABLE(keep one spare).
    4) you should have nearby Bullet mechanic

    New bullet is problem free

  30. Praveen on April 11th, 2012 11:26 pm

    I was so confused untill I read this ! gracias.

  31. prem on April 28th, 2012 11:44 pm

    a very informative article – great job

  32. Baskaran.tts on May 20th, 2012 8:15 pm

    Hats off for a wonderful review and thank the author to have shown light on the UCE Engine.

    I just own a brand new TBTS Thunderbird. Its awesome and smooth. All i can say is that if you still dont change yourself as time changes, You are a loser and a step back. When u want the old thump and feel.. be prepared to shell out more time,money, and resources.Even i own another diesel bullet and alternately drive both bikes. Love to tell u all that it has not even leaked a drop till date. thats a different story altogether. But still, if we dont keep pace of new technology, we will be forced to submit automatically very soon.. AMEN

  33. Rajesh on May 22nd, 2012 5:00 pm

    Hi Jay,
    I have read your reviews and appreciate the sincerity with which you have technically elaborated. I m planning to book a Thunderbird TS this week and felt much better after reading your reviews. Else it was quite confusing with contradictary reviews on multiple sites. Now I can go and book my pet with no confusion any more. Please share if you have reviewed TBTS as well.

  34. Sanket on May 26th, 2012 12:19 am

    It depends on what a person wants. These are britt bikes.. you own one? then learn how to take care of the same when she falls sick!

    Also.. UCE was introduced for a reason. It’s for people who always gave 2 sh!ts about mileage and efficiency. Well.. a GOOD Flat Tracker Cast Iron 500 can circle around the UCE 500′s ;)

    Once again.. it is also about Mileage for some people so for them yea.. UCE might be good! Stick to it :)

    -Sanket

  35. Kedar Bobde on May 26th, 2012 8:38 pm

    @ John I read all your problems..
    a) Accelator cable cut:- Riding a bull you should know basics..this is not difficult
    b) at very first day my bullet got puctured at 6am in Egmore – tht can happen to any vehicle
    c) Again one day my Bull got punctured in my home itself – refer to b, paid Rs.60 same rate in Mumbai..
    d) In Traffic, bull without self start really horrible thing to ride it. Check your bull for point setting and spark plug
    e) Bullet will start within a single press some days and also it wont start even so many kicks most of a time.- never faced tht
    f) If you ride it beyond 45kmph or 50kmph suddenly mileage will be 25kmpl or 20kmpl – little modification in fuel air mix will do good

  36. archibharat on June 10th, 2012 2:45 pm

    havent driven the new one but … but the whole fun of riding a bullet is going slow in top gear…easy cruising…the whole idea is to see things around you… since it aint no race track around to zip about…. so still the old engine rules

  37. jatinder on June 11th, 2012 11:17 am

    hey bro, thanx for the post man really enjoyed it and got a better knowledge about the difference between the two engines. I feel that the new UCE bullet is much better in all areas and I like it, but I still miss the old left foot breaks which was a RE exclusive in our part of the world. But hey what can you do about it, so I would better enjoy what I have got here. Once again thanks for the post bud. Keep riding and enjoying the “bullet”.

  38. Sanket on June 11th, 2012 8:57 pm

    Archibharat – I completely agree but if a guy want to take an Enfield to the race track then he can for sure. Also, I am talking about the old engines.. 1950s? Yes, those are used for dirt racing by many.. in India and also outside India.

    Here’s 2 clips – Enjoy!

    Part – 1

    http://www.youtube.com/watch?v=hej9srj3TCI&feature=share

    Part – 2

    http://www.youtube.com/watch?v=M-dK6nx9JJo&feature=share

    Another Hill Climb Video – http://www.youtube.com/watch?v=jz2BHmV3WBo&feature=related

  39. Sanket on June 11th, 2012 8:59 pm

    Also the above posted videos show things that can be done by ONLY Old Enfields. There are 535′s on this planet which churns out 55bhp 92nm Torque.. compared to stock 500 CI, giving 21bhp and 39.5nm torque. 612cc Cast Irons give around 52~68 BHP on the rear wheel and approxx 107nm torque. And yes can be done ONLY on cast irons.

  40. Hmd on July 16th, 2012 12:38 am

    I am totally agree with Mr,Sanket ..

    i have been using L 535 , tried 500CUE, felt as if it Honda or Bajaj or,,:-(..

    i found that L 535 is much better than 500UCE :-)..
    if you need power forget the fuel efficiency.

  41. Sanket on July 16th, 2012 3:50 pm

    Yea! Loving LB500! By the way… are you HMD from US RE Forums?

  42. Sathyavrathan PK on July 18th, 2012 4:59 pm

    @Hmd So you mean to say the new UCE models lacking power comparing with the CI models?

    It is true and so so bad that the UCE engines lacking the real thumping legacy of the Bullet, but I dont think it lacks Power.

  43. Sanket on July 18th, 2012 8:44 pm

    UCE is powerful when compared to STOCK Enfields. Like CI or AVL. Now people who are happy with less and what company gives..for them it doesn’t matter. It matters for them who will break their head looking at the smaller exhaust ports, loads of restriction in cam mechanism and also the EFI system. Even the inlet port has rough surface which restricts the flow. The steel insert and ring in the exhaust ports have the same. Even bigger than the ones used in AVL. You might feel loads of power in lower revs but past 100(Real Speed not Speedo Read) that’s where you go short of revs. Also, racing or revving with CV carb is waste. Many big time talkers will brag about their big carbs but end of the day CVs are made for one thing.. that is Reduced Emission and Mileage.

  44. Abhilash on July 30th, 2012 12:56 am

    Hi Bro’s,

    i want to take a bullet now of course i can’t get a brand new bullet with CI or AVI engine as am not really keen on taking a second hand, so Obviously i’l have to take a UCE engine, the only question i have is can’t we improve the THUMPING by changing the silencer.??

  45. Sanket on July 30th, 2012 5:14 pm

    Thump is something which is dependent on a lot of factors. Best bet will be the upswept silencer that you get from RE. Trust me, it’s a mix of thump and clarified engine clatter. Sounds good!

  46. Santosh on August 3rd, 2012 5:05 pm

    hey guys,

    i really dont understand why everybody is comparing the old ci engine and uce engine. Everybody knows the difference its the technological change. i own both uce and ci, both r good in their path. if its just the thump u want in uce , go for goldstar silencer u wil get it and bend the silencer nose a bit towards the engine side.

    santosh

  47. Hmd on September 8th, 2012 10:11 am

    Yes! i am in US RE Forums..

    In fact, if i would have UCE ,i would replace the wiring with i want and improve the intake …

  48. Hmd on September 8th, 2012 10:18 am

    The thump rhythms / beats depend on the cams profiles,though 500 CI,AVL & USE got same bore X stroke 84mm x 90mm.

  49. Suraj on September 14th, 2012 4:49 pm

    Awesome read! Having ridden a CI all my life I totally agree with what you have to say. The CI though still the original “Thumper” has out-lived it’s times. UCE is definitely the way forward for Royal Enfield as it offers you the great history and lineage of Royal Enfield and a motor cycle practical enough for your city and riding purposes. Here’s what I’d say: Keep your CI to get that really rusty and classic feel once in a while. Get a UCE (on my way to getting one soon!!!) and hit that highway without any worries of your bike breaking down.

  50. Suraj on September 14th, 2012 4:50 pm

    Has anyone tried installing a carb on the 500 UCE? Just curious!

    Let me know.

    Thanks!

  51. Sanket on September 17th, 2012 8:22 am

    A well maintained 350 or 500 never breaks down. Also EFIs can get a carb installed. Few friends did it already. Hitchcock offers a kit and many others do the same but my friends just disconnected the EFI unit and got carb placed. I don’t know if that has any negative effects because a lot of site talks about a lot of different things. BTW the work was done in Bangalore, in a garage named “Art of motorcycles” – By Junaid.

  52. alpha1 on September 18th, 2012 11:10 pm

    In the engine comparison you should’ve mentioned the peak torque figures and THE RPM where they are developed.

    That is THE KEY to the glorified “thump”.

    CI engine produced usable torque much earlier – even at 500-1000 RPM.

    An AVL used to struggle at that RPM, hence slight revving, and HENCE loss of that thump sound.

    I checked the UCE brochure – and they have raised the peak torque RPM further. Which only leads me to believe that you need to rev it even more than AVL to produce the same torque.

    End result? Even lesser thump sound.

    WHY is Royal Enfield doing this???
    We don’t want a high revving Honda VTEC engine on RE.

    You’ve done a good work on Engine, reliability, efficiency, Now RE I ask you just one more thing – improve the engine low RPM characteristic.
    And bring the classic thump back

  53. Hmd on September 19th, 2012 10:52 am

    Dont forget torque and power are related ;-)..They are really got good relation .

  54. Sanket on September 20th, 2012 8:37 am

    alphal – Are you talking about UCEs redline? The UCEs have 5500 max rpm, you can’t even get close to 5500 without few mods. Also, be it CI, AVL or UCE.. anything above 6000rpm will kill the con rod instantly! Maybe once or twice? maybe not even that and that is with the stock set up. Now there are very after market parts with which you can push it till 7000 rpm but those are very expensive!

  55. alpha1 on September 20th, 2012 4:14 pm

    HMD: yes power and torque are related. But that has got nothing to do with what I was speaking.

    At 800 RPM, the engine is just over idling. If it is not generating enough torque to counter the frictional losses induced while the bike moves – the engine will stall.

    The precursor to this is the lugging and knocking sound, which leads to very high noise and vibrations and ultimately the engine stalls.

    Now the CI engine used to generate USABLE torque even at 800 or so RPM. You could chug the whole day without revving the engine. In fact you could even count the engine stroke – the “dug dug” or “phat phat” sound is the power stroke.
    This means 1 power stroke in total 4 strokes = 200 thumps per minute. (= 3 thumps per second)

    What happened with AVL?
    The new design reduced the low RPM torque.
    That means at 800 RPM my AVL engine started stalling, thus I had to rev it slightly higher about 1600 RPM. This is where the engine developed enough torque to counter the frictional losses of the moving bike.

    Now audibly what difference does that make?
    Well the earlier thumps were 3 per second, now they are 6 per second.

    The higher the thumps per second, the more they tend towards the “VROOOM” sound.

    ***
    This is also a simple reason why thumpers are ALWAYS single cylinder bikes. Even the Harley cannot produce the thump (because of its two cylinders). Going further up to 4 cylinders – the bike will always sound like a car.
    Another way to make a single cylinder bike sound like a car is to rev it high.

    ***
    Incidentally, this is also the reason why Nano sounds like a goods rickshaw when it is idling. It is a two cylinder engine – so more distinct thumps per second than the usual 4 cylinder engine.

    ***

    Sanket, I think I have also answered what I was really talking about – the low RPM torque.
    Not the redline performance.

  56. Sanket on September 21st, 2012 12:30 am

    I got it. I think lighter the crank and flywheel, higher the rpm requirement. If a bike is stalling @ low rpm that is 800, that means the internals are lightened. I feel AVL has lighter internals than UCE. I was reading similar stuff on Classic MOTO Magazine, that’s a problem Classic bike racers face too. But 3 different REs they have 3 different purposes. Pick one which you think suits you best :)

  57. alpha1 on September 21st, 2012 11:20 am

    Sanket:
    Its not such a direct relationship between heavy/light crank and engine stall.

    The pistons produce a force, which depends entirely because of internal dynamics inside the combustion chamber.

    This force is translated to torque at the crank. Whether the flywheel is heavy or light does not change this torque.

    Flywheel is only for storage of rotational energy.
    (remember there is only 1 power stroke vs 3 non power stroke in a 4S engine) – so it stores the energy during the power stroke and dissipates it during the non-power one.
    Think of it as a water reservoir.

    So yes, it does help the engine cope with heavy torque requirements, but keep in mind this is only momentary.

    The actual torque is still being provided by the piston only. (think of water analogy again – if your pump cannot delivery water, the reservoir will eventually drain)

    So even if I put a heavy flywheel on Hero honda CD100 – it will never have the pulling abilities of an RE engine.

    Similarly, a CI engine has more pulling ability than AVL, and UCE has least. (Everything near the idling). Even if you put CI crank and flywheel on UCE, you will never be able to chug as slowly as your could on CI.

    The difference is in the engine.
    Therefore I said:

    “Now RE I ask you just one more thing – improve the engine low RPM characteristic.
    And bring the classic thump back”

  58. alpha1 on September 21st, 2012 11:36 am

    Check this out:
    chicaneculture.com/2010/05/basics-flywheel/

    Illustrates the basic difference caused by flywheel weight.

    So Sanket, you are right, heavy flywheel will make it easier to drive at lower revs.

    But I am right too ;)
    If the engine cannot deliver the torque to support the car load and the flywheel load – even a heavy flywheel will lose all its energy and engine will stop.

  59. Hmd on September 21st, 2012 1:16 pm

    Dont forget the ignition timing too.it got big roll ;-) .

  60. alpha1 on September 21st, 2012 7:47 pm

    HMD: we are not asking for anything that will actually reduce the efficiency and reliability of the bike.

    If your “ignition timing” refers to usage of CB points vs CDI or TCI – I am not ready to go back to the contact breaker ignition system used in old Bulls.

  61. Hmd on September 22nd, 2012 8:55 am

    alpha1.Have you had an experience with C.B ?.I Had it on L535.It was great if got tuned by perfect mechanic.it can be tuned to according to your test of drive..
    I remembered it was tuned accordingly even i could count the beats ,the idling was to slow was less than 400RPM..

    Anyway
    i switched to DIGITAL ELECTRONIC IGNITION KIT which has an improved advance curve which is more beneficial…

  62. Sanket on September 22nd, 2012 2:00 pm

    alphal – That’s some good info mate! Thanks!

  63. Vineeth on October 10th, 2012 10:08 am

    Hi
    Nice article,
    I have a concern here about the engine noise among CI, AVL, CI (Self start) and UCE generations

    I use 2009 Electra with self start (Not the AVL one), I am not sure how to name the engine as it is a breed, which make hell of noises even in idle conditions.

  64. Jay Prashanth on October 10th, 2012 10:14 am

    Vineeth,

    A well tuned Cast Iron engine is the quietest. Tappets and backlash are major sources of higher noise on a cast iron engine if the rest of the engine is in good condition.

    Cheers,

    Jay

  65. Hiran on October 20th, 2012 4:49 pm

    Will Barclay excellent inputs there. How do i reach u ?

  66. Mayur Chaturvedi on October 30th, 2012 1:03 pm

    Hi Jay,
    It was lovely reading your post. I had always been a little skeptical about enfields regarding the maintenance but have always wanted to own one. I have just 3 days ago booked a TBTS 350 cc model. The new one which the Co launched this month. Could you pls comment on it. Would like to have your opinion on it and also on my decision to book the new TBTB. Pls also add me to your mailing list. It would help a lot to get your advice and comments from time to time since this is my first RE and I certainly do not have your experience. Thanks. Have a nice day.

  67. Jay Prashanth on October 30th, 2012 1:28 pm

    Dear Mayur,

    You can subscribe to our feeds through email via feedburner which is on our homepage. That will deliver every update on ICB to your inbox.

    Coming to the latest TB350, it is a big improvement over the older model in terms of usability and handling. The engine is tried and tested.

    Cheers,

    Jay

  68. Mayur Chaturvedi on October 30th, 2012 6:09 pm

    Jay can u tell me what is meant by cam backlash and blowby.

  69. Pradeep Lucas on November 1st, 2012 7:43 am

    Awsome explation:)

  70. Shridhar Paregouda on November 5th, 2012 1:43 pm

    Well explained .Even a first time bullet user can easily understand.

  71. saurabh on November 22nd, 2012 5:19 pm

    hi jay,
    Please guide me on this. I am 32 currently i own RE bullet standard 350 four gear 2010 model,i am really fascinated by new thunder bird 350 and i am planning to buy it,but please advice me firstly should i go for thunderbird 350 over my old bike.and if yes then which is better classic 350 or thunderbird 350 ,secondly if thunderbird than 350 or 500. I would like to tell u that my daily drive is 30 km in city as well as highway my wish is to buy thunderbird 350 but dont know if classic 350 is better or thunderbird 350 ,i was told by RE agency that the engines are same please help.

  72. Jay Prashanth on November 23rd, 2012 9:38 am

    Dear Saurabh,

    If you ride on the highways, the Thunderbird is better than the Classic. If I were you, I’d keep the old Bullet as a vintage ride and buy the new one as a daily ride.

    Cheers,

    Jay

  73. saurabh on November 24th, 2012 7:25 am

    hi jay,
    Thanks for ur response,but i am still not clear ?? Should i stick to my old bullet or buy new thunderbird 350 coz i cannot keep two bikes.is it worth selling old bullet for new thunderbird 350 or not.

  74. Jay Prashanth on November 24th, 2012 11:54 am

    Dear Saurabh,

    If you’re looking for a higher top speed and performance along with added reliability at that performance level, the Thunderbird 350 is your option. However, if you belong to that school of riders who like thumping along at a leisurely 40 Kph in the city and about 60-80 kph on the highway, the CI350 is still a good bet. I’m saying this in the assumption that your CI350 has been reliable enough so far. Also, since the spares of the CI350 are freely available and will be so in the next few years, maintenance shouldn’t be an issue.

    Both the motorcycles feel very different to ride. I suggest that you ride them back to back to feel what suits you best.

    Cheers,

    Jay

  75. saurabh on December 15th, 2012 7:23 pm

    hi jay,
    I have booked classic 350,which will be arriving soon. Please suggest me that which silencer will be the best to get the thump like older models. Secondly i felt that the handle was bit uncomfortable ,one has to bend little forward to drive.can the handle of classic 350 be replaced by electra 350 uce handle or some other handle for comfort.how will it look and will it affect its handling.please help.

  76. Mohan Kumar on December 15th, 2012 8:34 pm

    Hi Jay,
    first i have to thank for the great info.
    I am planning to buy new RE classic 350 – the thing i have to know is that RE classic 350 is UCE bcoz i saw in one of the brochure of royal enfield mentioned every model (i.e STD, Electra, Classic 500, Desert storm 500, Chrome 500 & TBD 500) as UCE but classic 350 & TBD 350 they have not mentioned, & i didn’t get good response from them, so pls guide

  77. Jay Prashanth on December 17th, 2012 10:19 am

    Dear Mohan,

    All motorcycles produced by Royal Enfield currently come with UCE engines and this includes the TB350 and Classic 350 also.

    Cheers,

    Jay

  78. mohan on December 18th, 2012 7:41 pm

    Thanks Jay, finally i got cleared

  79. mohan on December 24th, 2012 2:46 pm

    Hi Jay, againg i got in confusion.
    Is the new Royal enfield 350 standard twinspark & Classic 350 shares the engine or different except self starter, pls clarify

  80. Jay Prashanth on December 24th, 2012 2:53 pm

    Dear Mohan,

    On the inside, everything is the same between the two engines except the eletric starter. Also, since the STD350 comes without the electric starter, the crank case is different.

    Cheers,

    Jay

  81. mohan on December 24th, 2012 3:38 pm

    k, thanks
    Is it better to go for engine with crank case heavier & what are the advantages
    what are the advantages of crank case with lighter one, and for me i use most of all in city sometimes on highway, which one you would suggest for me, pls reply

  82. Jay Prashanth on December 24th, 2012 3:48 pm

    Dear Mohan,

    I think you’re confusing heavy crank(shaft) with the crankcase. A heavy crank delivers better low end torque and this is terrific for the city where you can thump along at a leisurely 50 Kph. On the other hand, a lighter crank delivers better acceleration. AFAIK, the STD350 UCE comes with a heavy crank while the Classic 350 comes with a lighter crank. So, if you use the motorcycle mainly in the city, the STD350 would be a better bet for you.

    Cheers,

    Jay

  83. mohan on December 24th, 2012 4:37 pm

    Thanks Jay, I will buy STD350

  84. LK on December 27th, 2012 2:11 pm

    Hi Jay

    For sake of increasing thump in UCEs, any adverse effect on engine on changing to non standard silencers?

  85. Raghu Gowda on December 27th, 2012 2:16 pm

    Hi,
    so the uce engines of std350, electra350, classic350 and thunderbird350 are one & the same except std350 that is having heavy crank shaft and all others have lighter crank shaft & wat’s the advantages & disadvantages of shaft with lighter one

  86. Jay Prashanth on December 27th, 2012 3:48 pm

    Dear LK,

    Ideally, a free flow/derestricted exhaust muffler should be accompanied by a rejetted carb/remapped ECU. However, if you don’t plan to do constant high speed wide-open-throttle runs, you’re engine won’t run too lean. It’s better that you opt for the short bottle-type muffler rather than stuff like a free flow Goldstar/straight thru pipe.

    Cheers,

    Jay

  87. Jay Prashanth on December 27th, 2012 3:51 pm

    Dear Raghu,

    Yes, that’s right. A lighter crank equipped engine will rev up faster. Also, it’ll will feel less sluggish when given quick throttle inputs.

    Cheers,

    Jay

  88. raghu gowda on December 27th, 2012 3:54 pm

    thanks jay

  89. mohan kumar on January 5th, 2013 8:13 pm

    Hi Jay, handlebar of classic can be fitted to STD350

  90. vipindas on January 8th, 2013 8:02 pm

    excellent post my man. one of the ever self explaining one. anyway i agree cast iron and uce is not comparable but am still a fan of cast iron. whatever technology in uce engine i am sure there is no build quality. brand new uce bullets having electrical problems and the old tappet noise. and i am not agree with you as you told uce will last longer than cast iron. I don’t think so my std bullet is 25 years old now and its working perfectly cool(of course mechanic is my best friend now. and i am wondering why all these new uce bikes always hanging around near to work shops. after 25 years my std will be still on road but i am not sure these high-tech computerized bikes will last. and also one mone comment is I don’t think so anyone want to ride a bullet 120kmp..the beauty of bullet is 60 kmph.if any one want achieve 120kmph there are many in market..

  91. Kedar Bobde on January 8th, 2013 9:09 pm

    Hey vipindas I agree with you in totality …technology will be better next year but that’s not the only reason you buy bullet for…I have 83 model and proud of same… This topic is never ending for us CI engine is our love so how can some one say anything..emotional bonding is all about having old bull …

  92. vipindas on January 9th, 2013 1:03 am

    HI EVERYONE I AM HAVING FEW TECHNICAL DOUBTS HOPE ANYONE CAN HELP ME..
    1)anti-backlash system or what is backlash,
    2)is there any instruments available in open market for checking/identifying/reading error codes related to the engine control unit in uce engine.
    3)how can we check weather the fuel injection system is performing up to the standards like fuel line pressure nozzle condition. (considering a normal bike mechanic is doing the job because i always know company service center people are not good with dealing problems not only for Enfield all bikes and cars and even electronic items.)
    4)how do we know these hydraulic lifters(tappets)performing good(oil pressure ect).a normal mechanic can say what is wrong with your ci engine without looking at it.. awaiting reply. thank you

  93. Biju Bullet on January 17th, 2013 11:33 am

    With due respect to your lovely article, I would like to express some of my opinions. Hope I didn't offend you or anyone reading this article:
    I m a diehard Royal Enfield lover and I love to maintain my Bullet. Why I love maintaining my Bullet is because the more I spend time with her rectifying problems, the more I love her. And, I am a guy who won't mind to tighten a screw even at mid-night.
    So, coming to UCE. Although it might be tension free or much "superior" engine but where is the challenge to ride it? Even a 18 years old can pick and ride one, but not the real Bullet. You can't just kick-start her, as and when you want. It need to earn the respect (or say techniques) from her to ride her.
    One more thing, Bullets are not Karizma or Pulsar (fast city-bikes) to ride at 120kmph but a decent and "Royal" bike. I am happy to ride at 60 kmph and enjoy the thumping music of Bullet.

    Regards,
    Biju

  94. Gyanendra on January 21st, 2013 8:15 pm

    @alpha1

    What an explanation of old bullet thump.. but it has induced few more questions in my mind…(I m not much of a technical guy)

    1. Considerable torque at low RPM d primary reason for thump then how come by changing d silencer in d new UCE’s good some good considerable thump(off-course not like old one)

    2. I have UCE CL350.. so changing the crank in my bike and then playing around wid bent pipe nd exhaust can produce d same old bullet thump?

    3. Can d crank be changed without any side effects..

    4. Without changing d crank can I get almost d same old bullet thump by changing d bent pipe nd exhaust? If yes den how?

    I am very curious abt it and assuming a detailed explanation from u as u seems to hv a vry gud knowledge….cheers \m/ :)

    Very informative article Jay…thank you so much for sharing the knowledge

  95. alpha1 on January 25th, 2013 11:28 am

    Gyanendra:
    1. Considerable torque at low RPM d primary reason for thump then how come by changing d silencer in d new UCE’s good some good considerable thump(off-course not like old one)

    The change in muffler just makes the new UCE sound loud. The quality is not the same. Get an old bull along with the new UCE, and note the frequency of thump-thump at idling. Then put in the first gear, start riding the bike and again note the frequency of idling. Do all these comparisons side by side.

    The thump-thump in old bull happens at lower frequency and thus is more authoritative than the “racy” new UCE.
    This happens because you need to rev the new UCE, otherwise your engine will start lugging and the bike will stall.

    2. I have UCE CL350.. so changing the crank in my bike and then playing around wid bent pipe nd exhaust can produce d same old bullet thump?

    You may try, but it won’t give the exact same sound. The cast iron engine block does make the sound a little different. But you should get very close.

    3. Can d crank be changed without any side effects..

    Of course! you have the heavy crank mods done to improve the low end performance, and light crank mod to improve the “racy-ness” of the engine.

    4. Without changing d crank can I get almost d same old bullet thump by changing d bent pipe nd exhaust? If yes den how?

    Now you can’t. As I said earlier – do the side by side test = old bull vs new UCE.
    Changing the muffler can only increase the loudness. It cannot change the RPM at which the bike feels comfortable.

    That RPM depends on the engine characteristics and the flywheel mass.

  96. Gyanendra on January 25th, 2013 4:36 pm

    @Alphal..

    Thanks a lot alphal for the reply.. I was waiting from quite some days :)

    The question comes back again, can just/only d crank be changed without changing or affecting other things? Possible? Won’t affect d engine/piston/valve/gear teeth etc..? Need a gud light on this as I might think of getting d crank changed at some point in my bull’s life :)

    And I have one more doubt which needs clarification.. considerable torque at low RPM d primary reason for thump.. then that means when even d old bull is driven at high RPM the thump should diminish to noticeable ? Also if both UCE and old bull driven at high RPM where the torque produced is kind of same then must produce kind of same thump (apart frm other reasons neglected like design of exhaust nd engine metal making d sound different)..

    Thank you again

  97. alpha1 on January 28th, 2013 1:03 pm

    1. The change in flywheel (called crank by many) should not adversely affect the engine. What it will affect is the engine performance. If the Std UCE is available with heavy flywheel, whereas the other model is available with lighter one – it just shows that there isn’t much ill effect of the same.

    2. At high RPM the thump doesn’t really diminish. It just doesn’t sound like a thump anymore. Old bull as well as new UCE – both racing at 5000 RPM will never sound thump-thump-thump. It will sound more like a racy engine making a “vroom” sound.

    You’ve seen and heard the Piaggio APE goods carrier? The thump thump sounds harsh and bad but it is very loud, distinct and clear. It sounds bad because that’s how diesel engines sound. But the THUMP THUMP of that engine sounds loud and clear because of the extreme low RPM and extreme high torque (at low RPM) from that engine.

  98. Gyanendra on January 28th, 2013 6:57 pm

    Thank you once again for the reply Alphal

  99. ganesh puri on February 4th, 2013 12:46 pm

    I like article..i like new bikes….i will buy UCE engine bullet…

  100. Michael on February 7th, 2013 11:22 am

    Excellent article! I own a 2012 Classic 500 and love it dearly, though it was giving me some headache and finally got its engine replaced after 2500km. Struck by bad luck I’d say. The discussion is interesting to read, almost the same as in the forum here, between RE novice riders with UCE like me and pre-unit traditionalists.
    As for the thump: technically better skilled people than me explained that very low idling is probably even worse than high revving, as wear of material goes up. Also, floating bush depends on the oil film being build by revving above very low idle so leaving your engine at low idle or riding slow at high gear might sound cool but could be harmful to your engine. Don’t know if the same holds true for the UCE. Your opinion?
    Kind regards and greetings from Germany
    Michael

  101. Gyanendra Singh on February 7th, 2013 2:43 pm

    Hi Michael,

    Read your comments and I am surprised what went so wrong that you had to change your engine? That’s sad.. can you let us know…

    Thank you
    Gyanendra from India :)

  102. Michael on February 7th, 2013 6:04 pm

    Hi Gyanendra,

    well, it started slowly. Right after the first oil change at 500km, receiving 15W50 Motul semi, the engine developed loud, irregular mettalic noises at startup, going away at higher rev and engine warm up. I felt my 2012 was giving more vibrations than compared with the 2010 model and my dealer’s 2010 standard. There was wild guessing as of this noise was coming from the tappers or the auto deco. There was also a sporadical slippage feeling from the clutch with some noise plenty of time the clutch lever was released and the engine accelerating. The mechanics were clueless. During 2500km service, the dealer told me that there are difficulties with the engine..I rushed over there and they demonstrated…idle engine, clunky sound, getting worse when tilting the bike left or right. The seeked advice with the general importer for RE in Germany and he advised to messure axial tolerance of the crankshaft. It was way too high, upon order of the importer I received a replacement engine…and I was quite shocked…shortly after a couple of 100km I noticed oil draining from the gear sprocket. It was likely due to a assembly error in the factory not applying enough torque (80NM) to the securing nut pressing the sprocket against the gasket and washer. No it is winter time here and the Bullet is hibernating hopefully I can start into the new season without any issues. :-)

    Greetings from Germany
    Michael

  103. Gyanendra Singh on February 8th, 2013 5:06 pm

    @Micheal

    Sad to know what happened with you but good that you got the engine replaced. I hope everything will be fine now but as you know and they all say this Bullet’s have these tendency to give their owners nightmares but when they run all well then they run like a dream and the rider feels like heaven :) Thank God my Bull Classic 350 is running all well now and 3000 Km completed. Hope everything remains smooth… Cheers… By the way just wanted to ask, what you guys do their in Germany if you need for more thump in the Bullet? DO you guys goes for silencer change? Does the government/traffic rules allow that?

    Happy Thumping
    Gyanendra

  104. Michael on February 8th, 2013 7:51 pm

    Hi Gyanendra,

    Thie depends on age and technology. The older the vehicle, the less regulations. On a 1950′s Bullet you can probably get away with everything, but not on a more recent one. Today, all vehicles need to be EUR approved and such approval is valid throughout the EU. Approval procedure checks every freaking part of a vehicle, noise, emmission, power, stability, brakes. Even trafficator glasses and mirrors or headlamp glasses are checked. So, everything relevant bears an “E” sign on it, including the silencer. If your vehicle falls under the new regulations, getting checked by the police and having parts on your bike with no E sign will get you a fine. And in case of an accident this might void your insurance. In the UK, for some funny reason, they don’t care much about mufflers with no E sign, so I could get one of these. But that would be illegal to use here. Very recently a company from Italy introduced replacement silencers for EFI with E sign. Engine specs are not changed, but they might sound better. For even a better sound, they come with an optional “sound manager” – a flap in the exhaust. Gaps in the approval procedure measure noise only under certain conditions. The rest is undefined and in theory noise could be louder then. However, price is steep, above 500EUR for the silencer. Power kits are different. On EFI, one would need to adjust ECU mapping. Hitchcock’s sell a “Power Commander” for example….of course, no E sign… :-)
    But even if EFI got the least “thumpiest” sound of all Bullets, it’s there and the Royal Enfield gets a lot of attention and adoration by almost everyone. Being asked I sometimes reply with “not as old as you might think” :-)

    Cheers
    Michael

  105. Gyanendra on February 18th, 2013 3:55 pm

    Thanks a lot Michael for such a detailed and informative reply. I wonder, it is really a struggle in Germany to get the thump in new UCE engines because of tight government rules which are in one way very good cause they are made to have a less polluted environment…

    I have one more question though
    Does new Royal Enfields only available in 500 CC in Germany/Europe or are they available in 350 CC as well?

    Cheers
    Gyan

  106. Brian Quadros on February 19th, 2013 4:25 am

    ?

  107. Michael on February 20th, 2013 12:02 am

    Hi Gyanendra,
    only a “subset” of the 500cc models are sold here. However, 350 pre-unit have been sold a long time ago – perhaps on a private basis. Expats returning from India after a minimum 9 months stay may return with their Bullet as a “household” item and bypass many of the regulations. But yes, only 500cc are available here. The model range is likely to be extended by the upcoming cafe racer. :-)

    Cheers
    Michael

  108. LK on February 20th, 2013 10:48 am

    I am now owner of Bullet 350 UCE (Heavy Crank) and my sincere THANKS to Jay and indiancarsbikes.in. Its only this article and all the comments here that helped me to decide for 350 UCE.

    Very happy with my decision. All things said here are true. 350 UCE is bullet of 21st century. Still turns all the eyes on road. But definitely when a well tuned cast iron bullet passes by, it shakes the earth and I feel to have nothing but a shiny toy in my hand.

    Those who can still manage to maintain a cast iron bullet, hats off to them. They are true bulletiers ridden by passion. As for me, I’m happy to balance passion and practicality. Std Bullet still carries the century old look which every indian is familiar with, atleast I inherited that from old legacy. And I can still do daily office commute without much of a toolbox… :)

    -LK (Mumbai)

  109. Pushkar Dey on February 24th, 2013 10:34 am

    Now days they are giving 10000kms and 1 year which ever is earlier waranty….i have expired it in 3 months… am sad…

  110. Tushar Kamath on February 27th, 2013 12:23 pm

    Brilliant piece. Honestly, I've had enough of this cast iron chauvinism. First if it's not a a cast iron it's not an enfield, then if the gear shift isn't on the right it's not an enfield. I mean come on, where do you draw the line to this stupid idea that unless you get a fracture starting it or if it doesn't break down it's not a Royal Enfield.
    I'm a proud rider of a 2010 Tbird. There are many UCE riders who spend every weekend, cleaning, servicing and learning everything about their bike with their mechanic, more so than most cast iron riders I know.
    Yes, the CI's have character and riding a 4-speed right side shifter is just nirvana {having riden a 1967 std 350 on several occasions}, but this annoying statement of "UCE's not being enfields" is bogus & it's high time riders learn to appreciate a good move forward by RE.

  111. Biju Bullet on February 28th, 2013 2:36 pm

    That only a person who doesn't mind to get grease on their pants can understand!

  112. Biju Bullet on March 13th, 2013 7:17 am

    What is life without problems? U ride a bike which gives no trouble and eventually u forget what bike u r riding! I get closer and understand better as we goes on solving the problems.
    BTW, I learnt many things during my tenure with my "Black Monroe" and breaking down on a nowhere highway is just another hiccup for me now! Well, thanks for sharing ur view!

  113. vikas gururani on March 25th, 2013 4:32 pm

    Thanx Jay for your valuable inputs.I own a UCE Standard 350 cc BULL & after reading your article I am proud of it as initialy I was feeling very down that it does not produce the thump of the CI bullet but now I realize that there are other important factors than only the THUMP.thanx again…

  114. Rathu on May 7th, 2013 3:14 pm

    I guys i like to buy a Royal enfield 350cc standrard in 2nd hand i think its 1994 model is it worth to buy that model r i buy a new UCE type

  115. hitesh on May 7th, 2013 10:47 pm

    @ Rathu: if it’s RE Bullet std 350 cc then simply go for it. u will love it.

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