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-   -   Carberry comes up with 'Vibration Reducing Plate' for Royal Enfield UCE engines (https://www.team-bhp.com/forum/motorbikes/194636-carberry-comes-up-vibration-reducing-plate-royal-enfield-uce-engines.html)

A week back, Carberry Motorcycles (the company who are selling the 1000cc V-twin RE and engine) have come up with a very interesting little part for the Royal Enfield UCE 350 and 500 motors.

http://www.carberrymotorcycles.com/Accessories.php

I did some research on this and learnt a bit about it:

The current UCE motors have 2 bearings on the crankshaft on the left side (primary chain side) but just one on the right (clutch side). Behind the clutch housing lies a plate covering the cams.Now, because of this arrangement of bearings and the quality of materials used by RE, it might be possible that the crankshaft flexes a bit at higher RPMs leading to extra vibrations (over and above what is already exists lol:.)

What Carberry have done is create a new plate that enables them to place another bearing at the end of the crankshaft after the gear that drives the cams. This in theory should yield additional stability to the crankshaft and reduce vibrations at higher RPMs. Honestly how much difference will it make? I do not know yet, but it is very interesting nonetheless.

The cost of this plate set is INR 3000 (as per Carberry site) but is out of stock. We can send mails to Carberry in case we wish to buy one (which i have done already.)

Cheers.

Well I am in line too, thanks for the heads up.

This just might make me stay for a while longer on RE platform.

I will definitely pay that money if it makes a drastic difference in the amount of vibration post 60 kmph. I read on the Internet that the mouthing of the engine has to be done on rubber bushes to counter the vibrations.

I cancelled my booking after I rode a friend's CL 500 long distance and experienced first hand the horrendous vibrations after 70kph. Prior to this I had never really had the chance to go over 60 kph on the test drive bikes and had booked the Gunmetal grey CL 350 on an impulse driven by what is possibly the beginnings of a midlife crisis.
As things stand now, I am not that keen on a RE Classic given that these are rubbish if you need to take them out on the highway. If this solution by Carberry does work, I might just change my mind.
I have been riding the aforementioned CL 500 for a couple of months and after 2000 km on the clock have come to realise that these machines are indeed very flawed. There is, however, a certain undeniable character to these bikes but vibrations are unforgivable. Obviously there are solutions but RE is too busy making money to bother.

Hope this is a work in progress, rather than the finished product.

For those who think it is going to tackle REs vibration problems, the short answer is no, its not.

Regards
Sutripta

So, is there any way to actually damp the vibrations? Any reason you feel that Carberry's solution won't work?

No. One has to appreciate the source of the vibrations, and then realise nothing short of a major architectural change (from engine design, to how it is mounted in the frame) is going to tackle it.

My opinion: - This tackles a non existent problem (radial loading of overhanging portion of a shaft). And its implementation in my mind raises a lot of red flags. Which is why I said I hope its a work in progress.

Regards
Sutripta

PS - if Carberry people are on the forum, would love to hear from you.

I think I would like to see some real data comparing the vibrations before and after at various engine speeds before I would consider buying this plate and bearing.
This sort of information is easily obtained with several high quality accelerometer's positioned on the engine.
Surely a company like Carberry has such information. Hopefully, they will share it with us.
As for vibration of the Royal Enfield UCE engine, I found mine is considerably less than a Honda CX500 I once owned.

I often ride my 2011 Royal Enfield at speeds of 90-105 kmph (56-65 mph) for long distances on highways and IMO, there is very little vibration at those speeds.
In fact, it is rare for me to ride any distance at any speed below 65 kmph (40 mph) even when I am riding in the city.

If your Royal Enfield seems to have excessive vibration check the steel bar that connects the rear of the cylinder head with the frame. (It's called a "head steady").
If this is broken or loose, a great deal of vibration will be felt.

Also, check the lower engine mount bolts to make sure they are tight.
If they are loose at all a large amount of vibration will be felt throughout the machine.

While looking at the engine mount bolts, also look closely at the frame tubes.
Occasionally, a crack at the weld joints will happen and if it does it will give the same apparent vibration as a loose engine mount bolt.

From the description it seems they are doing a tuned Mass damper. If it can reduce vibrations on a new vehicle it is good. However if you use it to mask the symptoms of worn engine mounts etc., I would not recommend it.

I understand where you are coming from and was in the same boat years back when i rode other, more modern bikes. But after riding my Bullet i can now tell that it's characteristics like vibrations and weak brakes are more of something you accept rather than something you have to accept. If you plan on using your bike to cruise around on weekends, it is a nice relaxing bike to ride. Choosing the type of bike you want comes before the choice of model. As for this plate, i am sure it wont make a world of difference and for sure wont completely change the character of the motor but might make a slight difference if you are on a 400 kmph ride with friends on faster bikes.

I would say that a problem might seem like a problem after it is solved. The crankshaft flex might be present at higher RPMs not due to the design but quality of materials used (not an expert, cannot be sure of this.) Hence this plate could iron out some vibes as it will transfer the crankshaft radial flex energy to the crank case itself through that bearing they place. As mentioned by others, solid data will give a clear picture.

Thanks for the tip, Jim. Looking at the international reviews on youtube, I suspect that vibration damping on the CL500 sold in international markets is far superior than on the Indian version. The mirrors seem to be steady even when the reviewer accelerates hard. I have ridden a handful of 350s and a 500 so far and once you start to accelerate, you can't see anything in the mirrors. An Australian reviewer also mentioned that the bike cannot be started with the side stand open and its a pity RE did not see fit to bless us with this feature.

You do have a very good point. Even with all its defects, I look forward to riding the bike and have always returned after a ride with a big grin on my face. There are tractors that are more refined but this thing does grow on you. That being said, I am still sitting on the fence where buying one is concerned.

A number of points:-

Torque pulses - The way to tackle these is with a rotating tuned mass attached to the shaft. Thus the dog pulley vibration damper, and now the dual mass flywheel. A single cylinder is going to generate huge torque pulses, and is going to overwhelm these these solutions.
And do you see any changes to the magnet assembly - the rotating mass attached to the shaft?

In terms of NVH, this comes well below those caused by unbalanced reciprocating masses.

In the traditional RE, the engine is part of the frame. No isolation.

The flywheel obviously cannot have a support. (The pilot bearing supports the GB input shaft. Not the other way around.) But have you come across any case where the pulley end of the crankshaft is not overhung? Even with the OCD Germans who put CVs instead of UJs on propeller shafts.

Regards
Sutripta

One question. Is it a actually a Mass damper? Because the crankshaft vibrations are not because of offset load due to crankshaft design but just its flexing due to mismatch in main bearing and location and numbers for each side. I am sure had this shaft been a single forged piece, this sort of solution might not have been needed. Just my thought.

Cheers.

Well, I doubt the effectivness of it. No offence to anyone.
If Carberry can do then why can't RE themselves with the help of their much stronger R&D team?
Is it just a gimmick? Need to wait and watch

Even I doubt that this will make a huge difference but if it can improve things a bit, it's probably worth the 3k they are asking you to fork out.
As @naturaldisaster pointed out, this can make a difference over a 400km ride. The fact that this thingamajig is already out of stock is a bit suspicious. I refuse to believe that they flew off the shelves that quickly.
To answer the second bit of your post, RE will never do this because they dont give a rat's rear about their customers. They feel that things like vibrations, rusting, broken sprags are not defects but part of the "character" of the bike.