Boxerworks.com

I have a 1979 r65 and have always experienced vibrating mirrors and hands at
certain engine revs BUT have got some lead to cut up and put inside the bar ends .
What weight is sufficient in your experience for each bar end ?
Thanks to all and this forum for help in the past , I now have minimum stiction in
the front forks .
JIM

carb sync?

I cast some solid lead weights to be a tight fit inside the bar ends they would have been approx. 100mm long. Sorry I can't tell you the exact weight. They made so little difference that I drilled them out again and had more success playing with the torque settings of the engine mounts. I concluded that there must be more science involved than just a dead weight in the bar ends. I should have known better because back in the 80's I had factory fitted bar end weights that made a significant difference on a Suzuki. They were steel bars a little smaller in diameter than the bar aperture and fixed at the outer end only by welding. I wondered if this was so that the weight was free to vibrate inside the bar. Certainly when I removed the welded steel bars and replaced them with lead I never achieved the original level of vibration reduction.

It matters little what the composition of the weight is. Far more important is the total mass and the damping. Both the weight and damping would have to be found by experimenting, unless someone has done the work and published it.

hal wrote:carb sync?

+1 and check at higher rpm's too. But first go ride a Harley and then you'll realize how smooth it is...

As mentioned on my website, a carb sync is done by most at idle. Do it at the road speed where it vibrates the most. This can make vibration decrease in many cases, but then the sync will be off just off of idle. I think it clear which is more important.

The objective will be to disrupt a resonant harmonic frequency.
I have achieved successful results by injecting polyurethane foam ...

Duane Ausherman wrote:It matters little what the composition of the weight is. Far more important is the total mass and the damping. Both the weight and damping would have to be found by experimenting, unless someone has done the work and published it.

http://www.suckindiesel.com/thingy/view ... ?f=2&t=463

Duane Ausherman wrote:As mentioned on my website, a carb sync is done by most at idle. Do it at the road speed where it vibrates the most. This can make vibration decrease in many cases, but then the sync will be off just off of idle. I think it clear which is more important.

Yes, it is clear: around town it's the off-idle. Touring it's at cruising speed.

What's "most important" is always dependent on the situation.

I use another tiny trick on my own riders. I leave the left carb cable lock nut only finger tight. That way I can go down the road, reach down with my left arm and adjust the throttle easily.

You are probably wondering about the rubber sleeve that keeps water out of the carb top. It isn't designed to be lifted up and down quickly. I cut the bottom ring off of it so that it slips up and down easily. It no longer will tend to seal out any air, thereby allowing some air in at the carb top. It does keep out any rain and that is more important than the possibility of an air leak.