handle bar vibration

[DJones]

I have a noticable vibration in the handle bars that leave my hands numb after riding about 20 min. I have a `79 GS 1000E with aftermarket bars and Oury Road grips. I have checked the engine mounting bolts; one was missing. I replaced it and retourqued the others. What can I do to reduce the handle bar vibration?

[robinjo]

Re: handle bar vibration

I have a noticable vibration in the handle bars that leave my hands numb after riding about 20 min. I have a `79 GS 1000E with aftermarket bars and Oury Road grips. I have checked the engine mounting bolts; one was missing. I replaced it and retourqued the others. What can I do to reduce the handle bar vibration?

Balance the carbs
Set the ignition timing
Foam grips
Bar ends
Something called a "bar snake" or lead shot and silicone
Find a way to rubbermount the handlebar clamps

These options have been mentioned on this forum, I personally know the balancing the carbs does reduce vibration. Havent tried the other options myself.

[Anonymous]

Agree with the above post on the carb balancing/engine tuning. Also consider installing a jet kit if you haven't already. The lean mid-range jetting required for emissions laws also causes the bike to run somewhat rough.

I had a similar problem on my 97 ZX-9 (I know, I know ;-)) this summer and I installed a set of bigger bar end weights that I had a buddy machine up. They weighed about 40% more than the stock ones and made a MAJOR difference in the felt vibes. I would say they reduced vibes by about 35%-40%. I can send you a drawing of them if you want to have someone machine up a set for you, but you need to have threaded inserts in the end of your bars for them to work.

The bar snake is a heavy, flexible hose-like piece that you slide inside your bar and it sits loosely in there. The dirt bike people use them to reduce their vibe problems (if you think your GS shakes, try a big single...). I have not used one myself, but I have talked to several people about them and heard generally good things. Results do seem to vary some, though. YMMV

What you are really trying to do with all of this is change the natural vibration frequency of your bars so that they do not shake easily at the same frequency as the engine vibration. This means that you can lower the natural frequency (by adding weights), raise the natural frequency (by stiffening the bar), or add damping (the bar snake/silicon/lead shot/urethane foam approach). Or any combination of these if necessary. It can be analyzed and scientifically solved, but that takes major equipment and knowledge to achieve. For practical purposes, it is usually a cut and try sort of thing.


Mark

[DJones]

Thanks for the info!