[mr_dove]

My current shock is a progressive 5th element coil from a number of years ago. They're not serviced any more but I called Avalanche but it was fairly expensive to have it rebuilt so I decided to find a cheap craigslist shock that I can still get serviced.

I found a Fox Shock Vanilla R that matches my 7.875 x 2.0 but it doesn't have a spring.

Can I take the spring from my Progressive and put it on the Fox?

 

[JRogers]

It's hard to say, but it would probably work. Older Van R shocks took a smaller diameter spring, but had no reservoir to rub on; newer ones are probably DHX size and I think a progressive spring fits those. So I think it would work, but it's hard to know without trying; springs from different manufacturers can sometimes rub on the shock body if they do not center properly and have bigger coils.

But I should add that, more importantly, I don't know if it matters if it will fit. 5th Element shocks used very low spring rates. Newer Van R shocks may have changed a bit, but they had really high spring rates. For example, I had a 5th element on a DH bike and I think it had like a #275 spring. I put on a Push-tuned Vanilla RC and the spring had to be more like #450. Whether your current spring would fit or not, I'd budget money for a new spring anyway.

 

[Nick]

1st: yes, the ID and OD measurements of the spring do differ, and you do want the correct size.

JR: that doesn't make any sense to me. The make/model of shock wouldn't effect the leverage of the frame, and that is what would determine the spring rate. I could see a small variance after custom tuning, +/- 50lbs or so, but not that much.

 

[JRogers]

JR: that doesn't make any sense to me. The make/model of shock wouldn't effect the leverage of the frame, and that is what would determine the spring rate. I could see a small variance after custom tuning, +/- 50lbs or so, but not that much.

Part of the equation here is whether we are talking about a new or old Fox shock. I do not know about the newer ones, but the old ones needed higher spring rates than a 5th in my experience- often more than 50lbs, especially if the frame has a higher leverage ratio.

The same spring rate might work for both in this case, but I think there is some chance it won't. Since price might be a real concern here, I might have overstated my case a bit so that the guy didn't buy the shock assuming that the old spring and/or rate would work without any issues. It might, but it might not.