Bars shaking when not holding on

[Hatchetman240]

Occasionally I like to take my hands off the bars for 3-5 seconds to crack my right wrist. On my trip this weekend, while the bags were on and loaded I let go of the bars like that and there was an ever so slight wobble that began and within a few seconds was approaching tank slapper severity. This happened randomly, about 30-40% of the time that I did it.

It seems to only happen with the bags on but I cant be sure. I am leaning more to blaming the wear of the front tire (6100 miles on the stocks). Has anyone else experienced this that might enlighten me? I will be getting pilot roads on there come Friday and will retest for this issue to see if it is resolved.

[Beach]

There was a long discussion on this topic a short while ago. I'm a bit lazy to do a search to find the link for you...

Someone dug up a list of possible causes for this to happen. A change in weight distribution can upset the balance of bike quite easily.

As a follow up to my experience with this - I was running Shinko tyres when I noticed this head shaking. There was a mention that it could be the construction of the tyres, as per the list that was posted.

After that, I have run a set of Bridgestone's with no 'bar shaking UNTIL the tyres neared the end of their life. The front cupped a little so that would seem to be indicative.

I now have another set of Shinko's fitted and so far the bike is rock steady, despite worn suspension that badly needs updating.

As a side note, I find the Shinko's to be a very good tyre. If anyones interested in trying a set, send me a PM.

Brett.

[4N099]

If you're running the factory tires they will indeed shimmy and shake if you let go of the bars. I don't think it matters whether you're running the bags or not, I think it's because they start cupping at about 3-4K.

[steventhechef]

4N099 is spot on. You'll notice the head shake stop if you change the tyres out. The BT's cup and will give the symtoms you describe.

If it still persists check the head stock next but I'll bet it is the tyres myself.

[MrFixit]

I think it is probably wheel balance related. I have fairly new michelins on and just noticed a small shimmy at about60 kmh (35 mph) with my hands off the bars. I don't feel anything with my hands on the bars so will just ignore it.

[soccert]

Originally Posted by 4N099

If you're running the factory tires they will indeed shimmy and shake if you let go of the bars. I don't think it matters whether you're running the bags or not, I think it's because they start cupping at about 3-4K.

Noticed the same thing last week and replaced tires this weekend and slight shake is gone. The BT OEM tires were cupped and had 6800 miles on them.

[Sprint_DA]

I never noticed that on my BT's, but I did have an issue with it while running some ContiRoad Attacks! I think it's just bad luck and tire wear. New tires should get rid of it.

[zuzka600f]

Hi
Another reason of shimmy (except luggage) can be wrong (low) tyre pressure. Try to check it.

[oldndumb]

I am far from being a tyre or handling guru, but I do know that all MC front tires will cup to some degree sooner or later. Some of our tyre shredding members will wear the front out before the cupping becomes evident. The less skillful riders, such as myself, will more than likely cup the fronts before they wear out.

I have never had a bike do a bar wobble from cupped tires. I did +200 miles yesterday morning on a cupped front tyre and was able to do the usual hands off periods with no wobble.

Again, I am not a tyre or handling guru. This is just my personal experience, but if my bike wobbled, I would not blame it exclusively on a cupped tire. If that was the sole cause, there would be one heck of a lot of wobbly bikes on the road.

[LoVel]

I had a similar problem a few weeks ago that I attributed to the cupped front tire. It only occured at very low speed such as a quick stretch coasting up to a red light. New tire and the problem is gone.