Thread: Twin shocks

Originally Posted by rick130

The oil used in most all dampers is pretty average. I've done some rudimentary viscosity tests on OE Koni fluid and it was pretty poor, Silkolene Pro RSF 5wt leaves it for dead

Was this the clear fluid or the red stuff?
My twin tube front koni's have ATF in them, but others I've spoken with found clear fluid in theirs.

I agree completely that twin shocks are good idea if you're overheating singles. But you still need to keep the overall damping appropriate for the task.

Originally Posted by Dougal

It's quite simple.
Drive over corrugations slowly, the whole vehicle feels each one. Drive faster and faster and you'll only touch the peaks.
It's about frequency response. Damping reduces the speed (and frequency) that the wheel can move at. Resulting in in contacting the ground less often at higher frequencies.

Stability and traction are not the same thing. Acheiving a suspension setup that acheives both is the difficult part.

Slunnie's motor racing observations are correct, but he didn't mention that your average racing can has suspension that's twice as stiff (twice the natural frequency) as your average road car.
That needs a lot more rebound damping to control.
The difference in spring and damper rates between track racing cars and rally highlights the differences quite clearly. To travel quickly on a rougher road, you need a much higher frequency response.

My background in suspension tuning is mountainbikes, the scenario is quite similar to motocross with the biggest difference being chassis weight.
Making a 2.5" wide tyre stick to a dirt track shows you quite quickly and easily what costs traction, overdamped rebound (esp the high speed circuit) is a killer.

Ah ok. That's the background. I also do little bit of XC. It's really easy to overdamp the suspension on the MTB. The suspension on those has a huge range of adjustability.