Rear Shock - what should the NM strength be for the Spring?

[marty400]

Hiya All,

For the Bod standard OE shock on a NC29.

What should the NM strength be for the Spring?


Is 125NM sound the right ball park?



Cheers
Martin

[greggo]

Mate I tried to work this out be converting to Kg/mm but something aint right. All the measurements I know are in Kg rather than NM.

If you can work back the other way you are looking for something in the vicinity of 5kg/mm I think. For racing you go up to about 6.5kg/mm.

Someone please correct me if I am wrong.

[stimpy]

i know a stock cbr600 spring is a 12kgper summinsummin...it went back to 8kg when i first had it set up...ran wide,so a new spring fitted up to summin like 16kg...
all i know is,after that last spring was fitted,when i got on the throttle the bike tightened up on the line instead of running wide...thats the only info i could offer the suspension guy
really,im no help lol
stimpy

[greggo]

My understanding of the rear suspension hoodoo is that the spring rate is related in some way to the leverage and linkage. You can have quite different springs on bikes of the same weight.

I say this in case I got my previous post completely wrong.

It's known as 'blame shifting'

[CMSMJ1]

Spring rate is a function of force over distance.

The leverage a system puts on the shock can be altered with linkages that alter the force per mm travel.

If the force exerted drops off at the end of the stroke - it is a falling rate system (not too common)

if it ramps up - it is rising rate - used to make sure you can have supple start of the stroke and it then gets stiffer to stop bottoming.

...shit..got work..

[Cammo]

Racetech has some measurements on their site, none for the nc29 but you might be able to compare it to the 600 that peeps install.

http://old.racetech.com/evalving/menu/searchstreet.asp" onclick="window.open(this.href);return false;