1983 GS1100ED - Michelin Pilot Activ - Speed wobble. :(

[CCM911]

32 front/36 rear. My first pull to 100 on the way to work was fine. Then the wobble came back!!!

This is driving me crazy!! So am I limited to under 100 on this bike? I may as well just ride my Ninjette 250 instead.

[Cipher]

So did you check the swinging arm bearings? Wheel alignment? Steering bearings?

[TxGSrider]

I'm not sure what the problem is... but I can tell you that I am envious of you guys that have a place to do 100+mph on your way into work. lol

[dantodd]

I'm not sure what the problem is... but I can tell you that I am envious of you guys that have a place to do 100+mph on your way into work. lol

You'll notice he didn't say "legally" go 100mpg.

[posplayr]

Well something is wrong. Did you ever drain the forks and replace the fluids. Differential damping rates can cause uneasiness.
When my bike was modified but with stock suspension I always has a low speed 30-35 mph wobble on the front steering with hands off but nothing about 50mph.

The main thing I had added was Ohlins rear shocks, Racetech emulators, progressive F springs and fork brace. Other than that went through everything.

[TxGSrider]

You'll notice he didn't say "legally" go 100mpg.

On top of that, he said on his way "to work"... Im not sure I've ever had a job that I wanted to get there in that big of a hurry. Now going back home is an entirely different scenario.

[ShadowFocus603]

On top of that, he said on his way "to work"... Im not sure I've ever had a job that I wanted to get there in that big of a hurry. Now going back home is an entirely different scenario.

Hahahaha so true.

[bonanzadave]

Did you ever drain the forks and replace the fluids. Differential damping rates can cause uneasiness. I did when I installed new fork bushings
When my bike was modified but with stock suspension I always has a low speed 30-35 mph wobble on the front steering with hands off but nothing about 50mph. Mine is fine hands off the bars from 40mph down to 0.

The main thing I had added was Ohlins rear shocks, Racetech emulators, progressive F springs and fork brace. Other than that went through everything.

Mine has progressive front and rear. Swing arm bearings. Fork brace. All Balls head bearings. New Avons. Aligned 5 different ways. It might be off .125" max front to rear. Tightened every nut and bolt and looked at all the welds.

It feels like its hinged down the middle of the frame. Not a wobble but more like a weave that Im afraid could turn into a non recoverable wobble.

[posplayr]

Dave my original comments were for the OP but turning to your bike I recall you discussing this for sometime back. I'm not exactly clear what you are describing but but relate one more odd behavior that I had on my ED prior to the suspension swap. This is something that I attribute to a combination of things in a stock suspension but as a necessity you need to have weak or inadequately stiff rear springs.
I had gone through everything as you describe and even had non adjustable Ohlins on the rear but with the blank springs for 200 lbs rider.


when I has the rear loaded with substantial camping gear this was exaggerated. When on a heaving road in a constant turn the bike would try and lay itself down as the rear sank from the undulation of the road. As the rear lightened the bike would stand back up. I don't think there is any effect unless you are not going straight.

with a stiffer rear spring it tends to completely disappear. I can also relate the was chef1166's 1990 g1100l used to ride like it was on rails even with a huge windshield. No weave/wobble or any hint of instability . Bill is a big guy and had heavy duty springs on his progressive rear springs.

something to consider as I know they don't have to wobble or. Weave.

[Griffin]

There are a lot of dynamics at play when a motorcycle is going down the road. The larger the mass and the higher the velocity, the more exaggerated any imbalances or harmonic interactions become.

When I first acquired my 1000G (which has been my main ride for six years now), it had pretty stiff Progressive springs up front, stock shocks in the back, and a Vetter Windjammer mounted. The previous owner rarely exceeded 75-80 mph, and wasn't a corner carver, and never had any issues suspension-wise as far as I know.

The first thing I did was remove the front fairing. After that, I took it for a shakedown run to see exactly what I had. As soon as I got up to about 85-90 mph, it startled to wobble. I swapped out front steering stem bearings, examined the wheel bearings (they had been recently replaced when the p.o. put new tires on), and made sure everything was tight. I began experimenting with suspension settings, and figured out the wobble was caused by the shocks being too soft to deal with the shaft drive accelerating and lowering the rear end while the bike was at speed and still accelerating. As I softened the setting, the wobble worsened. I swapped out the stock shocks for some Koni shocks with heavier springs and better damping, and it mitigated the wobble, but it still was there at about 100 mph.

I installed a Cooley-style fairing and took it for a run, and the wobble was completely gone. Rock steady at a calculated 110 mph. Near as I can figure, the fairing changed the forces acting on the bike to either lighten the back or increase the front load enough to balance things out.

The bike had Bridgestone BT-45s on it when I got it. The next tires were Spitfire S-11s, they were ok at first, but as they wore the wobble came back and the handling deteriorated rapidly. I now have Michelin Pilot Activs on the bike, and they are extremely confidence-inspiring for me. No high speed wobble, rock steady in curves, and grippy to as far as I want to push the angle in a curve.

I've no idea what they 'd be like if I removed the fairing. Might not make any difference, might bring the wobble back. All I do know is that after messing around with several possible sources of the wobble, it went away.

[bonanzadave]

Bill is a big guy and had heavy duty springs on his progressive rear springs.

Thats what I have (Im 175lbs) and spring pre-load is set on the #2 notch. Front pre load is set on the middle setting and dampening knob is on #2.

Im gonna crank that rear preload way up (I think there is 5 notches) and see what it does.

Sorry Mr CCM911 for the highjack. I hope my 82 and your 83 suffer from the same thing so we can sort this out. Although it does deter from the chance of a 100mph speeding ticket.

[posplayr]

There are a lot of dynamics at play when a motorcycle is going down the road. The larger the mass and the higher the velocity, the more exaggerated any imbalances or harmonic interactions become.

When I first acquired my 1000G (which has been my main ride for six years now), it had pretty stiff Progressive springs up front, stock shocks in the back, and a Vetter Windjammer mounted. The previous owner rarely exceeded 75-80 mph, and wasn't a corner carver, and never had any issues suspension-wise as far as I know.

The first thing I did was remove the front fairing. After that, I took it for a shakedown run to see exactly what I had. As soon as I got up to about 85-90 mph, it startled to wobble. I swapped out front steering stem bearings, examined the wheel bearings (they had been recently replaced when the p.o. put new tires on), and made sure everything was tight. I began experimenting with suspension settings, and figured out the wobble was caused by the shocks being too soft to deal with the shaft drive accelerating and lowering the rear end while the bike was at speed and still accelerating. As I softened the setting, the wobble worsened. I swapped out the stock shocks for some Koni shocks with heavier springs and better damping, and it mitigated the wobble, but it still was there at about 100 mph.

I installed a Cooley-style fairing and took it for a run, and the wobble was completely gone. Rock steady at a calculated 110 mph. Near as I can figure, the fairing changed the forces acting on the bike to either lighten the back or increase the front load enough to balance things out.

The bike had Bridgestone BT-45s on it when I got it. The next tires were Spitfire S-11s, they were ok at first, but as they wore the wobble came back and the handling deteriorated rapidly. I now have Michelin Pilot Activs on the bike, and they are extremely confidence-inspiring for me. No high speed wobble, rock steady in curves, and grippy to as far as I want to push the angle in a curve.

I've no idea what they 'd be like if I removed the fairing. Might not make any difference, might bring the wobble back. All I do know is that after messing around with several possible sources of the wobble, it went away.

With my Maier fairing, the train light was somewhat back set from the fairing light opening (at least when I last did it) and it provided quite a gap to allow air to flow around the headlamp but inside of the fairing. Although I couldn't prove it, it seemed as if this channeling of air stabilized the front end. This was with my updated suspension, so it might be hard to distinguish the two factors.

No sure how fast it would go but I was on a track once that had a long 6% grade in about 1/3 throttle and looked down to see 135; no wobbles.

[ptegsotic]

and looked down to see 135; no wobbles.

I didn't notice any wobbles when I had your bike wound out !

[posplayr]

I didn't notice any wobbles when I had your bike wound out !

Yea, no wobbles.

Name change I see; Glad to see you back. Where you posted at?

[JJ]

On top of that, he said on his way "to work"... Im not sure I've ever had a job that I wanted to get there in that big of a hurry. Now going back home is an entirely different scenario.

When I was working, the trip to work took 20-25 minutes. The trip back home could take anywhere from 20 minutes to 4-5 hours!