Old GS handling limitations

[glib]

If you are talking about the complete set up, you'll need two spacers in the place of the units...at least on mine I do. Look at yours, mine support the bottom of the headlite mounts.

I was able to move the forks up 7mm and maintain the function of the air pressure equalizer. Any more than that and it could leak. Then I simply released the pressure from the forks until I achieved the desired pre-load and I believe I got an excellent result. Felt great last weekend. Just need the new front tire and I think I'm good for the season.

[Steve]

Then I simply released the pressure from the forks until I achieved the desired pre-load ...

I thought you had different springs in there?

What springs do you have?

1.0 (Based on calculator recommendation) And I like them...

With proper springs in the forks, the only "preload" you need should be mechanical, not pneumatic.

It does not matter how fresh all of your parts are, you WILL leak air from the forks. When that happens, you will return to your "too much sag" condition. Determine how much sag you need to remove, pop the tops off the fork tubes. Remove the spacers, make new spacers that are longer by the amount of sag you want to eliminate. That way, you will need NO additional air, which is a very easy measurement to duplicate for every ride.

.

[glib]

I thought you had different springs in there?


With proper springs in the forks, the only "preload" you need should be mechanical, not pneumatic.

It does not matter how fresh all of your parts are, you WILL leak air from the forks. When that happens, you will return to your "too much sag" condition. Determine how much sag you need to remove, pop the tops off the fork tubes. Remove the spacers, make new spacers that are longer by the amount of sag you want to eliminate. That way, you will need NO additional air, which is a very easy measurement to duplicate for every ride.

.

So currently there is no pressure when the bike is on the stand. I tried letting out the pressure with the bike off the center stand but the front dropped further and besides too much sag, I was concerned about my fender hitting the fairing.

[Steve]

Measure the distance from two points on the forks, or from the fender to a triple, while the bike is on the center stand. Do the same thing with you on the bike, geared up and ready to ride. You will obviously need a helper for that. That is your "sag". (You probably already know this.) That amount should be about 15-20% of total travel. Our bikes have between 5 and 6 inches of travel, so about an inch is a good number to shoot for. If your sag is 1.5", check your spacers in the forks, make some that are 1/2" longer than what's in there. That will raise the bike 1/2".

No worries about adding or releasing any air, just add some length to the spacers.

.

[glib]

Measure the distance from two points on the forks, or from the fender to a triple, while the bike is on the center stand. Do the same thing with you on the bike, geared up and ready to ride. You will obviously need a helper for that. That is your "sag". (You probably already know this.) That amount should be about 15-20% of total travel. Our bikes have between 5 and 6 inches of travel, so about an inch is a good number to shoot for. If your sag is 1.5", check your spacers in the forks, make some that are 1/2" longer than what's in there. That will raise the bike 1/2".

No worries about adding or releasing any air, just add some length to the spacers.

.

I got it. I was just making the point that even if you button up the forks while on the center stand, there will be some pressure in the forks when the bike is off the stand. My sag is good without adding any pressure but if I release the pressure once the bike is off the center stand, it will drop down a bit more. It does turn out that the spacer measurements that came with the springs were right on once I stopped adding air.

[Steve]

Since the cap pretty much seals the fork tube, any compression of the tube WILL increase the pressure. Simple physics. That is why you do all your pressure readings with the bike on the centerstand, so everything will be at a fixed, repeatable volume.

If you release some of that pressure when the forks are compressed, then put the bike back on the centerstand, you will have a partial VACUUM in the forks.

You might be better off removing your Schrader valves (your air-fill thingies) and putting in some plugs, so you won't be tempted to play with the pressures.

.

[glib]

Since the cap pretty much seals the fork tube, any compression of the tube WILL increase the pressure. Simple physics. That is why you do all your pressure readings with the bike on the centerstand, so everything will be at a fixed, repeatable volume.

If you release some of that pressure when the forks are compressed, then put the bike back on the centerstand, you will have a partial VACUUM in the forks.

You might be better off removing your Schrader valves (your air-fill thingies) and putting in some plugs, so you won't be tempted to play with the pressures.

.

I guess I could be accused of playing with my pressures but I’m not about to remove my thingies...and I got an A in simple physics. Really though, pressure was relieved while on the center stand and sag is good...and it feels good on the road.

[Old Colt]

So currently there is no pressure when the bike is on the stand. I tried letting out the pressure with the bike off the center stand but the front dropped further and besides too much sag, I was concerned about my fender hitting the fairing.

Are your springs firm enough?
personally I would not slide the forks up if you intend to adjust preload with spacers. Just set the spacers.
Fork Brace, If you stand in front of the bike and clamp the wheel between your legs, then turn the bars. Can you detect any twisting in the forks?
If everything is in good shape there should be no detectable twist. If you detect any twist get a good brace on there. Anything that clamps over the rubber boots is for show only.

Do you have a Go Pro?
Rig one up so you can review your ground clearance after a ride. There can be allot to learn from that since on the road you can not creep in on limits as you can on the track.

[glib]

Are your springs firm enough?
personally I would not slide the forks up if you intend to adjust preload with spacers. Just set the spacers.
Fork Brace, If you stand in front of the bike and clamp the wheel between your legs, then turn the bars. Can you detect any twisting in the forks?
If everything is in good shape there should be no detectable twist. If you detect any twist get a good brace on there. Anything that clamps over the rubber boots is for show only.

Do you have a Go Pro?
Rig one up so you can review your ground clearance after a ride. There can be allot to learn from that since on the road you can not creep in on limits as you can on the track.

Good idea. I never thought of pointing it back at the bike to see what was going on there.

The front is tight but I am going to put a fork brace on before my next ride. Just have to go through some shelves of parts to find it. The springs, Sonic 1.0, I believe are perfect.

[mmattockx]

"Shifting to the realm of unrealistic expectations, I rode on Saturday with a guy on an Aprilia 1000r and I was left wanting in the corners.

So am I expecting too much or is there more work to do?"

Since nobody has said it yet, yes, you are expecting too much. You can't compare a heavy 30+ year old bike with a flexi-flyer frame and skinny bias ply tires to a modern, stiff frame bike on big fat radials. That said, you certainly can make your bike much better and there is lots of good info here to do that.

Nearly new Michelin in back (3/4 in "chicken" strips).

You can lean much, much farther in that case. On my 1100E I have Shinko 230's, the front is scrubbed to the edge and the rear has about 1/4" of chicken strip (I assume from being pinched on the narrow rim). I have not touched anything down getting there in moderately aggressive street riding. I have 1" longer IKON shocks, Sonic springs with RT emulators up front and a Kerker 4-1 canister system that probably has significantly more ground clearance than the stock pipes. Cases and footpegs are stock and haven't touched at all.

Fast street riding is 50% how many chances you're willing to take, 40% rider ability, 10% bike.

If you and the guy on the Aprilia switched bikes, what would have happened?

That's a good breakdown and a fair question. I find riders are usually the determining factor, even on the track (at duffer speeds). A fast rider on a slow bike works way better than the other way around.


Mark

[glib]

Since nobody has said it yet, yes, you are expecting too much. You can't compare a heavy 30+ year old bike with a flexi-flyer frame and skinny bias ply tires to a modern, stiff frame bike on big fat radials. That said, you certainly can make your bike much better and there is lots of good info here to do that.




You can lean much, much farther in that case. On my 1100E I have Shinko 230's, the front is scrubbed to the edge and the rear has about 1/4" of chicken strip (I assume from being pinched on the narrow rim). I have not touched anything down getting there in moderately aggressive street riding. I have 1" longer IKON shocks, Sonic springs with RT emulators up front and a Kerker 4-1 canister system that probably has significantly more ground clearance than the stock pipes. Cases and footpegs are stock and haven't touched at all.




That's a good breakdown and a fair question. I find riders are usually the determining factor, even on the track (at duffer speeds). A fast rider on a slow bike works way better than the other way around.


Mark

Yes I realize that am the biggest challenge in the equation. I have a habit of seeking those with more skill from whom to learn so that I grow faster but then I get impatient quicker too. But it didn't help having the setup so far off.

[mmattockx]

Yes I realize that am the biggest challenge in the equation.

I wasn't dumping on you, I expect that is the case for most of us here. I am certainly the weak link on all of my bikes. Until you are at least an expert level roadracer I would say the bike is almost irrelevant as long as it is in good operating condition and well set up for your size/weight/ability. On the street I am not significantly faster on my GSXR1000 or ZX6R than on my 1100E for the most part.


Mark

[bonanzadave]

When you first said this.....

Since nobody has said it yet, yes, you are expecting too much. You can't compare a heavy 30+ year old bike with a flexi-flyer frame and skinny bias ply tires to a modern, stiff frame bike on big fat radials.

and then said this....

On the street I am not significantly faster on my GSXR1000 or ZX6R than on my 1100E for the most part.

I was a bit confused. So how about on the track ? Those are some pretty good choices to buzz around. Whats faster ?

[glib]

I wasn't dumping on you


Mark

Thanks but I really didn't take it that way. I did think initially "I gotta get me one of those" but I realize the guy was incredibly comfortable on his bike and has some skills. It does make sense to me that I would probably see little difference on the street from one bike to another--I think because my fear level won't be altered much by a higher tech bike.

[RichDesmond]

When you first said this.....



and then said this....



I was a bit confused. So how about on the track ? Those are some pretty good choices to buzz around. Whats faster ?

Track and street are very, very different. On the street the bike is almost irrelevant, on the track it does matter, although rider ability is still more important.
For a given rider, a modern sport bike will be quicker than the old GS around the track. How much quicker depends a lot on the rider. In general, a high level racer is going to be able to exploit the abilities of modern bike and be a lot faster. Guys at a lower level hit their personal limitations a lot sooner and will have a much smaller gap in times.