Old GS handling limitations

[Sandy]

Really? 10mm will do that? That would be about 7mm at the bottom of the header pipe and at a 45 degree lean that would be 5mm. Wouldn’t a bump in the road be more significant than that?

Well, my example might be a little extreme but I have done that on a previous GS1000 with track compound tires so yes it can happen .....maybe. 10mm might not be that critical but you do have to realize that under hard cornering the suspension does squat a whole bunch and if the road isn't perfect bumps will eat up some more. Ground clearancewise these old heavy bikes need as much help as they can get and stiffening up the suspension and dampening too much will just transfer the loads to an already wobbly frame. Don't get me wrong though, with a good setup and decent tires these things will handle quite respectably. Too soft they'll squat and scrape like crazy and too stiff they can get wobbly, gotta find that balance.

[glib]

Well, my example might be a little extreme but I have done that on a previous GS1000 with track compound tires so yes it can happen .....maybe. 10mm might not be that critical but you do have to realize that under hard cornering the suspension does squat a whole bunch and if the road isn't perfect bumps will eat up some more. Ground clearancewise these old heavy bikes need as much help as they can get and stiffening up the suspension and dampening too much will just transfer the loads to an already wobbly frame. Don't get me wrong though, with a good setup and decent tires these things will handle quite respectably. Too soft they'll squat and scrape like crazy and too stiff they can get wobbly, gotta find that balance.

Ok, I get that. In fact, when I got my bike it had Works shocks (which I recently rebuilt but have not installed), and they were leaking and had no nitrogen pressure (they take 245 lbs). I did scrape the pipes and scared myself before I realized what was needed. What a mess. I forgot what a learning experience this has been.

[Carter Turk]

Are the Works 13.5" eye to clevis? That extra 1/2'' out back makes a difference, not sure if yours are that length.
I get that the air fork crossover doesn't allow lowering the forks in the triple clamps much, maybe 3mm or so but I think even that helps a hair with turn in.

I have some ancient progressive springs in my forks, but ditched the 83 forks for older 80-81's as they have some preload adjustability on top and some minimal dampening adjustment on the bottom of the fork legs, which I don't believe the 83's have. No anti-dive BS either.
I think the pvc spacer I have in the forks is about 4" long, and the preload ramp on 2 or 3 of 4.
No air in forks and 250ML of 20W fork oil per leg.

I'm pleased how well the spindly 37mm forks perform doing trackdays, considering their age amonst all the modern machinery usually on the track.
They seem to work, though I do scrape alternator in long radius left handers, might be just my girth.

[Baatfam]

What do you mean by "wobble?"
No matter what you do, these old bikes will flex when cornering hard. You should feel the frame bending and moving around. Nothing to worry about, and I've always kind of enjoyed it.

[greg78gs750]

my 1100 es has a fork brace, emulators and rt springs up front, ikons in back and roadriders front and back. at track days, I don't notice any wobble and have ground the peg bumps off on both sides....any handling issues are due to my lack of ability rather than the bike.I would say I push about 8.5/10 at the track, not as hard as some, but much harder than I do on the street. I agree, replace the tire and go from there?

[Sandy]

What do you mean by "wobble?"
No matter what you do, these old bikes will flex when cornering hard. You should feel the frame bending and moving around. Nothing to worry about, and I've always kind of enjoyed it.

I mean exactly what you describe, fork brace helps. I find it sort weird that you can sort push past the flexiness once you're used to it or comfortable with it.

[mrbill5491]

With new Sonic fork springs, emulator, fork brace and the right fork oil, forget the air you don't need it.

[glib]

my 1100 es has a fork brace, emulators and rt springs up front, ikons in back and roadriders front and back. at track days, I don't notice any wobble and have ground the peg bumps off on both sides....any handling issues are due to my lack of ability rather than the bike.I would say I push about 8.5/10 at the track, not as hard as some, but much harder than I do on the street. I agree, replace the tire and go from there?

I'm going to replace the tire and add the fork brace. What rear shocks do you have and how much sag? My front feels much better with the 1.0 sonic springs but how much is too stiff and my rear feel mushy. I had half the usable range of motion (68mm) used up with sag.

[glib]

Are the Works 13.5" eye to clevis? That extra 1/2'' out back makes a difference, not sure if yours are that length.
I get that the air fork crossover doesn't allow lowering the forks in the triple clamps much, maybe 3mm or so but I think even that helps a hair with turn in.

I have some ancient progressive springs in my forks, but ditched the 83 forks for older 80-81's as they have some preload adjustability on top and some minimal dampening adjustment on the bottom of the fork legs, which I don't believe the 83's have. No anti-dive BS either.
I think the pvc spacer I have in the forks is about 4" long, and the preload ramp on 2 or 3 of 4.
No air in forks and 250ML of 20W fork oil per leg.

I'm pleased how well the spindly 37mm forks perform doing trackdays, considering their age amonst all the modern machinery usually on the track.
They seem to work, though I do scrape alternator in long radius left handers, might be just my girth.

My Works shocks are 13.0" eye to eye. I'll try raising the forks and adding the fork brace.

[Baatfam]

I mean exactly what you describe, fork brace helps. I find it sort weird that you can sort push past the flexiness once you're used to it or comfortable with it.

Yes Sir...I have a fork brace on the 1100E, plus replaced the bearings in the swing arm, steering head, and wheels a few years ago. It all helped, but you can still feel her flex, especially after riding one of my Triumphs...

[greg78gs750]

ikon shocks in back, don't know the sag off the top of my head, but i set it up "correctly" when I put them on. they are a bit over length from stock, 13.5 if i remember correctly....

I'm going to replace the tire and add the fork brace. What rear shocks do you have and how much sag? My front feels much better with the 1.0 sonic springs but how much is too stiff and my rear feel mushy. I had half the usable range of motion (68mm) used up with sag.

[RichDesmond]

I'm going to replace the tire and add the fork brace. What rear shocks do you have and how much sag? My front feels much better with the 1.0 sonic springs but how much is too stiff and my rear feel mushy. I had half the usable range of motion (68mm) used up with sag.

Is the 68mm the front or rear sag?

[Tom R]

I’ve had my ‘80 GS1100L on the track with a stock front end, Hagon 14” shocks on the rear and a fresh set of shinko 230s.... I had no problems scraping foot pegs and no wobble to speak of. Would mismatched tires contribute to this?
Move heard arguments on both sides about mixing tires.

[glib]

Is the 68mm the front or rear sag?

Sorry I wasn't clear on this. 68mm was the total travel in the rear with the Ohlins shocks (measuring from the base of the shock body to the bump stop with the shaft fully extended) and I was 32mm of sag if I remember correctly.

[glib]

I guess I haven't said so yet but I'll freely admit that I have limited skills but I think I'd do better on a track where the curves are completely visible and losing the rear won't splat you into a mountainside or to unseen hazards over a drop off. That said, I do think I'm fighting something other than fear and lack of skill and I appreciate the help in tracking down the possible details I've missed.