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Old 01-21-2009, 07:38 AM   #9
Jonex
zipper suited sun god
 
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Joined: Mar 2006
Location: Central Wisconsin
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Correct, typically on the track you'd use less rebound damping to speed up the suspension so your tires remain on the ground. Traction is better when the tires touch the pavement .

This type of discussion gets all complicated when you start throwing in things like expensive, very adjustable shocks which can deal with a wider variation of suspension deflection rates. Typical OEM suspension just plain sucks and has a wide variation in adjustment and capability, so "it depends" is the real answer here. There is no "always", but there are some thumb rules such as: increased spring stiffness tends to reduce traction, increased rebound damping tends to reduce traction, zip ties on the forks can help when setting pre-load so you use the most of available suspension travel and avoid bottoming, low budget steering dampers can cause wallowing, etc. etc.

I like to keep it simple, and knowing that I prefer a more compliant suspension, I just set the sack to about 1.25" and run as little damping as possible - just enough to keep the bike from getting out of shape in the bumps and have predictable sliding. But, I've always had screen door closers and slinkies for suspension so my choices of knobs to fiddle with have been limited. Back in 1989, I raced a GS500 on bias ply tires with stock suspension. I had to run max shock preload to keep from bottoming in turn one at Blackhawk farms. I had to carry the brakes way into the corners to keep the front end bottomed to prevent pogo sticking - basically the front tire WAS my front suspension. It doesn't get much worse than that. I felt all decadent when I got a bike with damping adjustments, and happily cranked all the kick out, only to find out the thing pushed like a Dodge Dart with bald tires.


Quote:
Originally Posted by FlyingFinn
Not claiming to understand all the interactions but the above statement doesn't make sense to me.
Faster speed -> need suspension to allow tires react quicker to road surface irregularities does make sense.

But to make "suspension faster" you would use LESS rebound damping, not more. Right?

For track use I can see how stiffer springs might make sense to reduce the change in bikes attitude and reduced ground clearance when either heavy on the brakes on way banked over. The stiffer springs (less suspension travel?) would in turn require more rebound damping to keep movements controlled.
But is springs are kept same for street vs. track setup, I don't quite get why more rebound damping would be good on track IF the rebound is properly set for street use.

In other words, the way I see it a suspension that's comfortable (compliant, responsive and doesn't "wollow") is also good for fast riding. No?

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Mikko

Jonex screwed with this post 01-21-2009 at 05:38 PM
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