high speed wobble

[sweet78xs]

On my way home tonight, I was passing a car swiftly and when I came back in lane, my bike devloped a slight high speed wobble. Enough that I backed off the throttle and let it straighten out. I was riding the highway earlier in my commute and at speeds of 90+ had no problems. What could cause this and how do I eliminate it? I have no handling mods. I was thinking about a steering damper. Anyone add one here?

Thanks

_Carey

[ross]

i'm not the guru.....

hey there sweet78xs......could of you possibly lost a wheel weight....like i mentioned b4...not the guru, but might be worth investigating....just my 2 cents.....talk 2 ya later...ross

[DiverRay]

1. check tire pressure front and rear
2. verify that the axles have been installed properly, Large nut tightened and THEN the pinch bolt, front and rear.
3. get a TKat fork brace
Just a quick list....

[sweet78xs]

I don't think I lost a weight, but possible. the road was a bit wavy, which I thought caused the wobble. I have ridden that road before, just not as aggressively

[sweet78xs]

Also, one other thing. I am constantly looking over the bike, feeling and looking for things amiss. I noticed that, right off the bat, the forks move foreward and backward going down the road. It's not like anything is loose, I made sure when I put new tires on. It's a flex type movement, enough sometimes that the front end seems like I lost a weight like Ross said. The fork brace wouldn't stop that would it?

[TopCatGr58]

Hey Sweet,

Check out these links:

http://www.xs11.com/forum/showthread...=&threadid=181

http://www.xs11.com/stories/handling.shtml

The XS's front forks are NOT as big around or robust, and so you "could" be seeing some flexing, but surprised you're seeing it on a Standard? I could see it more on the Special because they have longer upper tubes!? Are you hearing any kind of clicking or thumping with this?? If so, could be loose steering head bearings and triple tree tension/slack!?
T.C.

[olebiker]

Originally posted by TopCatGr58
Hey Sweet,

Check out these links:

http://www.xs11.com/forum/showthread...=&threadid=181

http://www.xs11.com/stories/handling.shtml

The XS's front forks are NOT as big around or robust, and so you "could" be seeing some flexing, but surprised you're seeing it on a Standard? I could see it more on the Special because they have longer upper tubes!? Are you hearing any kind of clicking or thumping with this?? If so, could be loose steering head bearings and triple tree tension/slack!?
T.C.

Yep I am with you on the loose bearings.

[Bunk]

Wobble

I used to ride a Honda V45 magna, and this bike was very sensitive to front tire pressures. Just a little low and it could get scarry. You could not take both hands off of the handle bars without your life passing before your eyes. The early V45"s were known to have skinny forks that caused this problem.

[strippedFJ]

All motorcycles will develop a speed wobble under the right "conditions". With cradle frames made of "water pipe", rather thin front forks, and an excess of 'free' length in the fork stanchions make it an inevitability when pushing hard on a bike from this era. On contemporary Honda CB9's you could watch the forks flex sideways under hard cornering, very disconcerting, especially if you come into a corner too hot.

An undulating surface will make the wobble problem worse, at certain speeds. Early-mid 80's Suzuki's were especially prone to it at around 180 kph. In fact the GSX1100EF had a bad (albeit undeserved)reputation for speed wobbles, and even the first generation FZR's used to be prone to it. Steering damper sales increased significantyly with the release of Big Jap 4's from the mid 70's.

Check all the items listed in the other posts, worth checking them occasionally anyway. But if nothing shows up as bad then I'd put it down to the specific situation causing the wobble.

A fork brace and steering damper will reduce/remove the problem. As will better quality front springs such as Progressives.

[Dennyz]

Don't over look the rear shocks. The rear swing arm of the XS is not very rigid. I believe that it is possible to get into an oscillation when in a hard turn. The swing arm can twist causing the shocks to become unbalanced. Particularly if one is bad.

My 'F' would only wobble when I was in a right had turn. My wobble went away when I installed new progressive rear shocks with stock springs.

[skids]

Yeah what he said. Also, try adjusting the swing arm at the pivot points.

Originally posted by Dennyz
Don't over look the rear shocks. The rear swing arm of the XS is not very rigid. I believe that it is possible to get into an oscillation when in a hard turn. The swing arm can twist causing the shocks to become unbalanced. Particularly if one is bad.