My vibration problem solved

I was experiencing what appears to be a fairly common vibration from the engine at around 2400 rpm that smoothed out greatly when the clutch lever was pulled slightly. It wasn't enough to make the bike un-rideable but was annoying on long trips as the vibration from the handlebars left the hands a little tingly after a long ride. The bike almost seemed to "buzz" if held at 4000 rpm. I have long maintained that there had to be something going on with a bearing supporting the clutch. It made sense to me that when pulling the clutch lever you are basically pulling the transmission input shaft towards the front of the engine and that that action "straightened" out the bearing and reduced the vibration. I had the engine apart over the winter and finally got into the clutch. Right away there were several things that I noticed. 1). Because of the anti-judder spring between the gears, it pushes the clutch basket away from the crankshaft. 2). With a force of 5-10 lbs the clutch basket moves about 25 thou downward and only 5 thou upward (this is a result of observation #1). 3). After removing the clutch basket and looking at the back where the torsional springs are, some of them have thicker windings than others (read heavier)
The clutch basket rides on a needle roller bearing supported on a sleeve that is clamped to the input by the nut holding on the inner basket. I took the sleeve and mounted it perfectly horizontal and placed the clutch basket on it where it could rotate freely and there was a definite heavy spot that rotated down every time. I experimented taping different weights to the outside of the hub until it was balanced. One gram either way was noticeable so I think that I'm within a half a gram. I wanted to balance it with something that was reversible in case this didn't work out so that eliminated drilling or welding so I machined out a 1/2" flat washer to a press fit on one of the rivet heads as it lined up perfectly with the unbalance. I then epoxied it as well for additional insurance. Just for reference the washer weighed 6.39 grams after machining.

The results: Reving the engine in the shop it seemed to be better but it is really hard to remember back to last year when I ran it last. I have a helmet lock mounted on the handlebars and the clasp would rattle like crazy at 4000 rpm before but is silent now. I was able to take her for a quick ride today (brrrrrr only 33 degrees Fahrenheit) about ten miles and it feels much smoother to me. Pulling the clutch lever still makes an improvement but the vibration is reduced considerably. At a constant 4000rpm like after you have geared down and are waiting to pass someone, there is no longer any "buzz" and it feels very smooth. The ultimate test will be after a long ride but that is still a ways away. We still have a foot of snow on the ground. Will update later.

But you still have the vibration, correct?
Keep us updated
Good try. Worried about the epoxy giving up and coming loose. Welding will warp it

Did you press the rivets to make sure they were compress right. Some have been known to ne loose
Even on new purchased clutch baskets. That alone could cause a harmonic vibration. Good luck but I think you turned it into a hand grenade waiting for the primer to strike. There is a chance if it comes of it drops and hurts nothing. But man if it does you arse will take a bike bite out of the seat. I had the internal hub explode at 80 mph bending the input shaft on the transmission licking everything up. No time to pray as I was busy scoping out the best place to bail !!!!!!! Sphincter factor 9. (Thats 9 days before the pucker releases and you can have a bowel movement) you sir I shall pray for

TheKid said:

But you still have the vibration, correct?

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I'm am just trying to be forthright in my observations. All engines have some vibrations and I believe that mine have diminished significantly. When I take it for a long ride I'll know how much of an improvement I have made but there is a definite improvement.

Warp: I didn't check the rivets specifically but if they were loose I'm pretty sure I would have noticed. Not concerned at all about the washer coming off. It was a very tight fit on the rivet. I scratched up both surfaces before I epoxied it. I'm sure it would take considerable effort to remove it

Also to point out a few things in your post above yes the springs on the back are of different load tensions, they take up the thrust shock to the drive train and crankshaft gear by this fancy backlash eliminator. The loose springs in your picture are not loose when the backlash eliminator has the tension. This is when the clutch basket is engaged with the crankshaft.

Now as for anti judder spring its inside the clutch basket but really aroung the inner splinned hub. Is exerts pressure outwards unless you tossit it up on the shelf with the anti judder seat
So I'm not really clear as to where you think or how you think the only anti judder spring is between the hears when its between the inner clutch fiber the only one of a karger inside diameter to clear the anit judder spring and seat. So your either confused or re-naming parts I'm not sure.

While your at post a picture of the lifter piec because the 2010 roadster should have the old pre roadster lifter piece.

Now you have me worried! I don't have a pic of the lifter piece but I thought that 2010 was the first year of the new style. If anyone would know it would be you Warp. I think it was the new style. It did look like new though. No burn marks at all.

I'm not confused about how the springs function but I may have not used the correct terminology. I think that you may have misunderstood what I was trying to say. When the crank gear is meshed with the gear on clutch, the pressure from the backlash eliminator spring pushing on the teeth is what causes the two gears to want to push away from one another.

I know that you don't like my way of balancing the hub and I would have preferred a couple of tack welds if I knew for sure that this was going to work but the point of the matter is that the clutch hub was obviously out of balance and was a definite reason to cause a vibration. My math is a little rusty but I did calculate that the weight of my washer at that radius would exert a force of about 10lbs at 2400 rpm and 36 lbs at 6000rpm.

Leftstarted in the 2011 touring right is 06 to 2012 standard, classic, roadster all black motors silver motors have a different backlash eliminator plates, pressure plate and lifter piece.

Thanks for posting the pics. I must have the older style lifter piece. Is it more prone to break the button end off? How worried should I be? I did just upgrade the clutch springs. On that note, I read in one of your posts that you tapped the clutch spring retainer bolt holes all the way thru and replaced the bolts with longer ones. Can you tell me your reasons for doing that. Did you have a problem of some sort that caused you to do it?

More on the vibration issue: Had her out for another ride today, about 20 miles or so. I tried to drive more like I normally would (just put Nev cams and pistons in and it's hard to restrain myself). I never really thought that there was excessive vibration at the higher revs(3000 and up) but I noticed today that just accelerating gently but letting the revs go to 4000, the bike seems way more "comfortable". It always seemed to be "buzzing" before. Same thing when gearing down. As the revs dropped, the clasp on my helmet lock would rattle etc and now feels very smooth. I am feeling more and more confident that this has made a big difference. Wound her out to 7 grand today and my washer is still hanging in there

31moppie said:

Thanks for posting the pics. I must have the older style lifter piece. Is it more prone to break the button end off? How worried should I be? I did just upgrade the clutch springs. On that note, I read in one of your posts that you tapped the clutch spring retainer bolt holes all the way thru and replaced the bolts with longer ones. Can you tell me your reasons for doing that. Did you have a problem of some sort that caused you to do it?

More on the vibration issue: Had her out for another ride today, about 20 miles or so. I tried to drive more like I normally would (just put Nev cams and pistons in and it's hard to restrain myself). I never really thought that there was excessive vibration at the higher revs(3000 and up) but I noticed today that just accelerating gently but letting the revs go to 4000, the bike seems way more "comfortable". It always seemed to be "buzzing" before. Same thing when gearing down. As the revs dropped, the clasp on my helmet lock would rattle etc and now feels very smooth. I am feeling more and more confident that this has made a big difference. Wound her out to 7 grand today and my washer is still hanging in there

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Not that it is more prone to breakage. But the newer one has a larger OD on the head which does two things. More contact surface on the lifter shaft which lessons the chance of burning the shaft. And it seems to have less room to rattle. Over all I'd say a improvement. Don't fret the next time your in her then you can change it out.