on a 06 crf450, im 157 lbs stock spring is 5.5, ihad 2 1/8 static sag when race sag was 4. i put a 5.0 spring on and it only changed stati sag to 1 3/4. strange thing is mx tech spring generator says i need a 5.2, which would make the static sag even more. most shops say static sag should be 1/2- 1 inch . what do ya think
When you put the 5.0 on, did you set the race sag to 4? Had to ask. 170 sounds about rider weight for a stock 450 to me. Some other variables, your actual weight with all your gear on, bike full of fluids, air in the forks, exactly where you are measuring, and I like working the suspension up and down a few times before I settle into me exact riding position, up on the tank?
Other than a miss marked spring? Never heard of that one, so what the heck, you have to have a variable somewhere? Use masking tape to show exactly where your at? Static sag has to be correct, or your shock will never work correctly.
there will be a free sag difference from pushing down on the rear and letting it settle vs. lifting it up and letting it settle.
take both values and get the mean value
ok, i tried it again last night with axact reference points. magic marker line on number plate. its actually 1-1/2 "mean" pushing down and letting it rise and pulling up and settling. as for race sag, i bounce on the seat and try to let it settle down. actually i dont have my boots and helmet on or fully gassed. i guess that would make a difference. ill try that and get the fork free sag also. i havnt seen a spec on fork sag thanks for the suggestions. i havent got to ride it yet but im curious how it works compared to the other spring.
There is no fork free sag measurement. The forks should work evenly with the back. If you change the rear spring, you will have to put the same weight springs in the front. What is 1 1/2? Your static sag? What does your manual say the range is? Gas, boots and helmet? 10 to 15 pounds? Gotta follow the rules.