Reducing Handlebar Vibration

[jpcoetzee]

With the original grips there is a lot of handlebar vibration on my 3½.

Any ideas for fixing this? I have heard of people filling the bar with lead shot, or adding bar weights. Has anyone tried these?

Many thanks

[EVguru]

Fix the engine!

It's going to be;

Ignition timing wrong on one cylinder (pickup or transducer).

Carb balance (stops and cables).

Uneven compression (worn bores, poorly seating valves, different head/bease gaskets).

Loose engine bolts.

If it's always been like it, then the engine may be out of balance.

[3narf]

Loose engine bolts.

I once lobbed in my spare engine for a Surrey MRC night and in my haste left the front bolts loose.

I couldn't believe the vibration, I thought the bottom end was shot (first time I'd used it).

Halfway there, it miraculously cleared! How we all laughed, at the pub, when an eagle-eyed member (Anne Cooper) pointed out the missing bolts.

[jpcoetzee]

I don't think there's anything wrong with the engine - it's just been rebuilt by Jim McLean here in Bristol and running very sweetly. Or do you get ZERO vibration on your bars at 70mph?

I think it's normal (my old Strada used to be worse) but I'd like advice on damping it.

[3narf]

Is it bog standard, or has it had a capacity increase?

Heavier pistons will cause increased vibration.

Early Stradas had rubber mounts for the 'bars, but the fork pitch is less than the later ones...

There's always a bit of vibration; primary balance isn't perfect (72degree V).

Sorry if you knew all this stuff already.

If you spend a lot of time at that speed, try a 40 tooth back sprocket to raise the revs slightly.

[Morinijen]

I fitted some bar end weights to my 3 1/2 Sport and they didn't seem to make much of a difference. Mind you, they are only lightweight aluminium ones, maybe stainless ones might be more effective.

On my Royal Enfield I fitted some barrel shaped 'Gran Turismo' handlebar grips and they really did dampen the vibration reaching my hands. The only down side is that they increase the reach to the levers which can be a bit difficult if you have short fingers.

You can get the grips from Hitchcock's Motorcycles for £6 ... http://www.hitchcocksmotorcycles.com/
... If you ordered them on line tonight you would probably receive them on Wednesday.

Best Wishes,
Jenny.

[3potjohn]

Sometimes I get a bit of a tingle in my fingers even on a K75S which is about as smooth as you can get. I think it may just be an age thing.Perhaps this is the reason I cannot get my hand into my wallet at the pub. I don't find my 350 overly vibratory in any rev range and just use thin rubber grips.Red ones of course.

[jpcoetzee]

Is it bog standard, or has it had a capacity increase?

It has NLM oversize pistons, 375cc.

If you spend a lot of time at that speed, try a 40 tooth back sprocket to raise the revs slightly.

I spend most of my time at about 40mph...

I have heard of poeple using lead shot or other techniques to weight the bars and I wondered if anyone here had tried it.

Thanks for all the help.

[corsaro chris]

If you're riding it at 40 mph in top gear that's your problem (possibly). You need to keep the revs above 3,500 - at 70 mph you'll be at the sweet spot around 5,500 - 6,000...?

If its not this, then follow the other suggestions

CC

[mgill]

My CB350 racer came with bar end weights and they help quite a bit,
although it still shakes alot up around 10,500. The rotor and all that extra Quieting weight has been removed though.
Be careful you don't over tighten them in the bar ends.
I'm guessing you could find a nice set of proper bar end weights
for less than 15 bps (sorry I've only got $ signs on my keyboard)
The lead shot thing sounds a little goofy.
Mathew