[kwrangln]

I tried this in the newbie section because I thought it would be elementary, guess not since it only got one reply. I got the the numbers are compression and rebound like I thought and that european vendors like bilstein use metrics, so start splainin.

Somebody explain shock valving to me. I'm looking for a replacement for my 5 year old rancho 9k. Read the product review for the bilstein 5150's and it lists 2 different valvings available. 170/60, and 255/70 so what the hell do these numbers mean? Simple terms please. guessing one is compression, and one rebound, how do these numbers compare to vehicle weight or unsprung weight? Trying to get away from the one size fits none approach to chosing shocks, help me out here.

Not listing vehicle or specs here because I need to understand the process, not just what will fit with no explination.

Thanks.

 

[KC_JoNeS]

"The amount of damping force produced by any shock absorber, twin-tube or mono-tube, is dependent upon the speed at which the shock's piston is traveling when the damping force is measured. Therefore, the velocity that your race car's suspension travels vertically determines the piston speed inside the shock. The faster the piston is forced through the shock's reservoir of oil, the stiffer the shock becomes on both the compression and rebound strokes."

shock valving

The basic point I want to try and make is that a shock with the stiffer valving might be a good candidate for a vehicle that moves comparably slower.

KC

 

[jeepman00]

Me too

I am also interested in this!

 

[KC_JoNeS]

another good read.

valving calculations

The Bilsteins are Metric, so the numbers you ask about are

170/60 -- or 170Nm for the compression / and 60Nm for rebound.

255Nm for compression / and 70Nm for rebound.

 

[Beat95YJ]

Just out of curiosity what is the vehicle application? Different vehicles will require different damping rates.

Toyota p/u's generally require very little damping in both rebound and compression. There is not a lot of spring rate, so excessive rebound is not required and interleaf friction provides compression dampening. Also excessive damping will set off chassis harmonics or shake in the vehicle.

Leaf spring Jeeps typically require very little compression, with quite a bit of rebound. The leaf spring typically will provide roll stability and compression stiffness by way of inter leaf friction. The arch in an aftermarket Jeep spring typically makes the rate very progressive, which will make it require more rebound than say a Toyota leaf. The rebound is really neccesary when the spring has been compressed as a lot of energy will build up in the spring.

Coil Spring Jeep vehicles typically require more low and midspeed damping to for adequate chassis control. Generally they have low friction bushings or joints which gives improved roll over (washboard type events) even with more damping than a leaf vehicle.

I hope this helps.