jmross Posted December 19, 2016 Report Share Posted December 19, 2016 (edited) I need help picking a spring rate for the rear shock. I only ride sand dunes. +6 swingarm and I weigh 240lbs. I called race tech they said I need a 12.something kg/mm. That didn't sound right to me. Thanks. Edited December 19, 2016 by jmross Quote Link to comment Share on other sites More sharing options...
jmross Posted December 19, 2016 Author Report Share Posted December 19, 2016 On racetechs spring rate calculator they list a 8.12kg/mm with my weight and a +3 swingarm. Im just shocked that another 3" in swingarm length needs a spring that much stiffer. Quote Link to comment Share on other sites More sharing options...
Sandking Posted December 19, 2016 Report Share Posted December 19, 2016 What you want is a 0900.225.0500 spring from eibach which is local to racetech and they can get it when doing a rear shock rebuild, I have it on both of my +4 swingarm bikes. Quote Link to comment Share on other sites More sharing options...
jmross Posted December 19, 2016 Author Report Share Posted December 19, 2016 Just put an order in with racetech. I went with a 12.5 kg/mm or 700lb/in as per their recommendation. Had to get a set of collars with it also. I'm guessing it's a bigger diameter then the factory spring. My shock has already been re-valved too. Hopefully the valving matches well with that stiff of a spring. Quote Link to comment Share on other sites More sharing options...
Sandking Posted December 19, 2016 Report Share Posted December 19, 2016 I had to do the collars also. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted December 19, 2016 Report Share Posted December 19, 2016 On racetechs spring rate calculator they list a 8.12kg/mm with my weight and a +3 swingarm. Im just shocked that another 3" in swingarm length needs a spring that much stiffer.When you make the swing arm longer it creates more leverage on the spring. Kinda like using a 24" crow bar vs a 36" crow bar. Far more leverage. Similar principal. Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted December 20, 2016 Report Share Posted December 20, 2016 FAST actually stocks and sells different springs as far as I know. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.