front suspension acting up

[Thewogster]

So I have been checking out and adjusting my new to me 97 TLS. The Olihns rear is magical but the front......hmmm. It's suppose to have Race tech springs and valves. I have adjusted the suspension several times and it seems to be fine with the amount of dive on braking and being stable.Buuuut As I'm going over a bumpy road (and we have them in New England for sure) It seems like the forks are bouncing back towards the bike rapidly. The road doesn't have to be big bumps just not smooth.
So I got home late and in the AM I'll check the steering head bearings
Dazed and confused.
Paul

[Hobo]

Re: front suspension acting up

Sounds like your rebound dampening needs softening up a bit, try goin down 2 clicks on that, mine was doing that.

[cyclecamper]

Re: front suspension acting up

The wording of your description can be misunderstood. I'm not sure exactly what you mean by "forks are bouncing back towards the bike rapidly" since that's impossible as the forks are mounted to the bike and the fork itself does not ever move toward or away from the bike, they only turn left or right. Are you taking about when you hit a bump too much shock is transmitted to the bike (problem with stock '97 compression valve body flow limitation but Gold Valves fix). Or do you mean that on the backside of the bump the wheel does or doesn't return quick enough / too quickly. If you ride over a washboard road with many constantly repeating bumps, does the suspension tend to pump up (front rises) or pump down (front gets lower)? Does the wheel bounce on the tire? Does the bike bounce on the road?

Can you describe the problem better?

[Mikey75702]

Re: front suspension acting up

The wording of your description can be misunderstood. I'm not sure exactly what you mean by "forks are bouncing back towards the bike rapidly" since that's impossible as the forks are mounted to the bike and the fork itself does not ever move toward or away from the bike, they only turn left or right. Are you taking about when you hit a bump too much shock is transmitted to the bike (problem with stock '97 compression valve body flow limitation but Gold Valves fix). Or do you mean that on the backside of the bump the wheel does or doesn't return quick enough / too quickly. If you ride over a washboard road with many constantly repeating bumps, does the suspension tend to pump up (front rises) or pump down (front gets lower)? Does the wheel bounce on the tire? Does the bike bounce on the road?

Can you describe the problem better?

from what I am gathering from the limited description, it sounds like the bike rides normal except Sharp edged bumps cause to much suspension travel.( high speed compression) if this is the case you need to have your forks rebuilt by a competent suspension guy. Since we don't have high speed adjusters on our forks, the shim stack is used to set this. The varying thickness and amount of shims controls movement over bumps that try to force the forks to much.

[Thewogster]

Re: front suspension acting up

The wording of your description can be misunderstood. I'm not sure exactly what you mean by "forks are bouncing back towards the bike rapidly" since that's impossible as the forks are mounted to the bike and the fork itself does not ever move toward or away from the bike, they only turn left or right. Are you taking about when you hit a bump too much shock is transmitted to the bike (problem with stock '97 compression valve body flow limitation but Gold Valves fix). Or do you mean that on the backside of the bump the wheel does or doesn't return quick enough / too quickly. If you ride over a washboard road with many constantly repeating bumps, does the suspension tend to pump up (front rises) or pump down (front gets lower)? Does the wheel bounce on the tire? Does the bike bounce on the road?

Can you describe the problem better?

Yes forks are not moving back, it was bouncing so quick (tire off the road) it looked like they were.
So as I said just getting the bike and on my first good ride I noticed right away it was set up wrong. I had a minute today and while checking things out I noticed the rear was going down when I sat on it but was not rising back up when I lifted up off the bike. So I backed the rebound on the Olhins off and lightened the compression. adjusted the front some and took it for a ride and it was Much better.
Sunday I have the time to get it right as I can, I'll set the sag front and rear and start the dialing in.
Paul

[Thewogster]

Re: front suspension acting up

from what I am gathering from the limited description, it sounds like the bike rides normal except Sharp edged bumps cause to much suspension travel.( high speed compression) if this is the case you need to have your forks rebuilt by a competent suspension guy. Since we don't have high speed adjusters on our forks, the shim stack is used to set this. The varying thickness and amount of shims controls movement over bumps that try to force the forks to much.

Yes the info was limited when I bought it, he had the forks set up with Racetech goods buy a local stealership I believe.I sent an email to him to ask some things.It had Lindemann Engineering Motorcycle Race Suspension stickers on it but I don't know if he had them set it up, if so I don't get the joke. He is lighter than me and this thing was set up way to stiff front and rear.The Ohlins was not even working the way it was set.
I'll see what Sunday brings, it's much better with the small adjustments I've done. I'll do it all properly then.
Paul

[cyclecamper]

Re: front suspension acting up

Can you desctibe the problem symptoms better please. Use your own words to describe what it feels like as you approach the bump and as you leave it.

The Wogster thinks it's got too little compression damping, like the Racetech has too few shims on the stack and the gold valve bodies are allowed to flow too much. But now you say the opposite, that it's too stiff up front. Yet the other guy was lighter...

You've got to learn low-speed damping from high-speed damping and low-speed rebound from high-speed rebound and how that all feels seperate from the spring rate and preload.

The adjusters are low-speed adjusters but of course that low-speed bypass also bypasses at high-speed (but at high speed it has less effective compared to the large amount flowing when the stack opens).

Start with the basics. Evrybody has a different procedure, mine is just speedy and from the gut. Check the static sag with you on it and set the preload. Then I like to open the adjusters and evaluate just the springs, bouncing on it, trying to tell whether the spriging is too progressive due to the fluid level, or doesn't have enough fluid to prevent bottoming out. Then I increase both compression and rebound until it controls the wheel. Then I drive on a really rough road and see if it pumps up or down and whether the wheel follows the surface or skips over it, and I adjust the rebound appropriately. I like stiff springs to control pitch and dive, instead of the hydraulics. Good luck.

It really really helps if you have a friend with a really good video camera and can get it to the track and get movies of it going over some bumps.

[cyclecamper]

Re: front suspension acting up

Count the turns to close each of hte adjusters, and write each down. Then you can always return to those settings or know where you started.

Then fiddle with them (keep the two sides of the fork the same as each other). That's how you learn what each does.

If the problem is the fuid level, which creates a progressive spring to prevent bottoming out, or too much fluid can limit travel, then that's a little harder ot experimeint with.

So first off do you "think" the prolbem is in springing or damping?

Do you "think" the springs are too stiff or not stiff enough (like with the damping opened)?

Do you "think" tha damping is too much and making it stiff or slow, or pitching and diving too fast? Do the wheels or bike bounce like the suspension is locked too solid, or bounce and keep bouncing like there's nothing absorbing the bounce?

[Thewogster]

Re: front suspension acting up

Count the turns to close each of hte adjusters, and write each down. Then you can always return to those settings or know where you started.

Then fiddle with them (keep the two sides of the fork the same as each other). That's how you learn what each does.

If the problem is the fuid level, which creates a progressive spring to prevent bottoming out, or too much fluid can limit travel, then that's a little harder ot experimeint with.

So first off do you "think" the prolbem is in springing or damping?

Do you "think" the springs are too stiff or not stiff enough (like with the damping opened)?

Do you "think" tha damping is too much and making it stiff or slow, or pitching and diving too fast? Do the wheels or bike bounce like the suspension is locked too solid, or bounce and keep bouncing like there's nothing absorbing the bounce?

I was bouncing like they were locked, but not hitting hard. I guess you could say like an old ridged frame only in the front.The back like I said is much better from when I changed the setting. The front is also better. But like I said I'll get into it on Sunday the proper way. Your advise is well taken.
I'm trying to get some info on exactly what was done inside the forks.
I'll get it sorted.