Viper Shock Spring rates

carey

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Oct 20, 2015
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138
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PA
I recently picked up a pair of KYB gas shocks from a Viper. I want to install them on my 2002 Venture, but I don't know if the springs will be stiff enough. I know the spring rates for my Venture shocks, but no amount of searching will reveal Viper spring rates. I can't find any marking on the springs.

Both shock bodies are stamped S25F, and both springs look to be progressively wound. The center shock spring measures 215mm/8.5 in. long, with no preload and the rear shock spring measures 406mm/16in long with no preload.

Anyone know how I can identify what spring rates I have?
 

I show center shock 1.3-3.0 kg/mm for the Viper and 1.2 for the Venture.
rear shock 3.0 - 5.0 for the Viper I think the Venture is the same. Try them if they don't feel right swap your springs onto them......................SRXtreme
 
I show center shock 1.3-3.0 kg/mm for the Viper and 1.2 for the Venture.
rear shock 3.0 - 5.0 for the Viper I think the Venture is the same. Try them if they don't feel right swap your springs onto them......................SRXtreme

Thanks for the reply. I decided to pull the spring from my Venture shock. With the spring on my bench, I took measurements and used a spring rate calculator. My measurements may not be 100% accurate, but they told me the Viper spring was 170 lb/in and my Venture spring was 201 lb/in. I'll install my Venture spring on my Viper shock.
 
The Viper springs are variable rate though. Just something to keep in mind......................SRXtreme
Both springs that I measured were progressive, but it wasn't very uniform. Both rear shock springs were about 16" long, and the progressive part was only the first few inches, the remainder was fairly uniform.

I decided to put the OEM shocks and springs back on my Venture for several reasons. First, based on my measurements and observations, I don't think the Viper spring rate on the rear shock is heavy enough and the non-gas shock on the Venture definitely has more rebound damping than the KYB. Since I haven't even ridden this sled yet, I decided to ride it stock to see what, if anything, needs changed. Long term, I'll probably have the Viper shocks revalved and resprung for my Venture.
 


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