Do ics springs figure as part of total spring rate

[Bigman]

On a CRF Showa fork the spring rate is said to be .47. Do the inner chamber springs figure in that number? Or do you not figure those springs in the spring rate. The reason I ask is because for my weight(240) the charts say I should have a .49 fork spring, but I don't know if the ics spring figures in that #. If they do count what is their rating, and what springs do I need.
Bigman

 

[marcusgunby]

they dont come into the rating of the main springs,you have to figue the best combination for your riding, i think they go
1.6,1.8,2.0,2.2,2.4
im not sure of the std one on the 450.
goto www.mx-tech.com and punch in your numbers, most of the rates it produces are about right IMO.

 

[Jeremy Wilkey]

BGM..

The ICS Does impact functional fork spring rate! That's about all it does, besides impacting preload slightly.. (Almost nil in current forks).. If you have a .47kg/mm main spring and you have a 2.2kg/mm ICS Then you have a .51 kg/mm effective Spring Rate.. Changing ICS is a waste of time and money generally.. It has nothing do with style, or conditions anymore than adjusting spring rate.. I've posted some numbers off a spread sheet we use that calculates out rate as a simple mathematical relationship to Ratio of areas.. (Which is all there is going on)

I ran the same numbers using a lighter ICS.... For comparisons..



Main rate Kg/mm ICS rate 1 Kg/mm ICS rate 2 Kg/mm ICS piston radius mm cartridge shaft radius mm ICS shaft radius mm ICS Preload mm ICS Preload mm Main Preload mm Overall rate 1 Overall rate 2
0.47 2.2 1.5 17.00 6.00 5 2 2 6 0.511 0.498
907.46 113.04 78.5