I'm in the process of getting a set of Bilsteins re-valved and need to know the wheel rate for 21mm torsion bars, which looks to be 172 lbs/inch, but would appreciate confirmation. There is a large degree of variance over on the bird board.

I can't find the rear wheel rate anywhere. Someone must know. I have a very vague recollection that is 0.9 or 90% of the spring rate. Assistance appreciated.

Howie.

Noone?

Maybe I should have asked the question like this:

If the rear wheel goes up and inch how far does the shock move?

H

Well, it's been a long time, but IIRC the motion ration for the rear is 1.17:1.

Memory challenged....

Andys

Thanks Andy. Therefor 1/1.17 = 0.85. So for each inch of wheel travel the shock moves 0.85 inches. Which means that the wheel rate is 85% of the nominal spring rate.

For every inch of wheel travel, the shock mounting point travels 1.17 inches; BUT the shock is at an angle, so you'll have to calculate the required rate using one of the online calculators like this one:

http://www.qa1.net/technical-support/stree...pring-rate-tech

or

http://www.hypercoils.com/spring-calculator

Andys

No guarantee on accuracy, but my kinematics model shows an overall spring motion ratio between ~0.9-1 depending on suspension position (in this case I'm running stock suspension points with 25" tires so the trailing arms are essentially level @ 0).

Click to view attachment

Thanks. That helps.