modified coil rear shock?

single-pivot

Likes Dirt
Hey has any one shortend coil shock before ?
saw one for sale once

Wondering if its viable
resone for there are always cheap fox coil shock 4 sale in the 216 x 63 sizes . Looking to go 200x57
cheers
 

dug8713

Likes Dirt
Can be done if you're competent with tools. The RC4 is pretty easy to work on and you won't need too many specialised tools.

Provided you've got the donor shock & all the parts work, the parts you'll need to change over are the shaft, reservoir, body and metering rod. Bear in mind that Fox changed the shaft diameter in the later model RC4 from 5/8" to 1/2". You'll need to check the shaft diameter of the donor shock to make sure the new shaft will fit, otherwise you'll need a new seal head too.
 

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Boom King

Wheel size expert
Can be done if you're competent with tools. The RC4 is pretty easy to work on and you won't need too many specialised tools.

Provided you've got the donor shock & all the parts work, the parts you'll need to change over are the shaft, reservoir, body and metering rod. Bear in mind that Fox changed the shaft diameter in the later model RC4 from 5/8" to 1/2". You'll need to check the shaft diameter of the donor shock to make sure the new shaft will fit, otherwise you'll need a new seal head too.
So you can change a 216 x 63 into a 200 x 57, provided you already have a 200 x 57 as a donor?
 

dug8713

Likes Dirt
So you can change a 216 x 63 into a 200 x 57, provided you already have a 200 x 57 as a donor?
Hmm I meant donor shock that is of any length other than the desired 200 x 57. You end up using half the parts (i.e. HSC assembly, rebound piston, both eyelet assemblies etc) as they are the same through all shock lengths.

Thinking about it now, you'll be forking out for the donor shock along with parts to replace half the shock. It may end up costing as much as a brand new DVO Jade or CC Inline Coil.
 

SummitFever

Likes Bikes and Dirt
Cheap way is to add a 6mm spacer on the damper shaft below the piston to reduce stroke to 57mm and eye to eye to 210mm. Then two sets of offset bushings will shorten the eye to eye down to 204mm. This will get you pretty close without changing any major components.
 

dug8713

Likes Dirt
Cheap way is to add a 6mm spacer on the damper shaft below the piston to reduce stroke to 57mm and eye to eye to 210mm. Then two sets of offset bushings will shorten the eye to eye down to 204mm. This will get you pretty close without changing any major components.
I've thought about doing this before, but the problem that might stop it from working is the rebound port in the shaft. See photo with rebound port circled in red.

As the shock rebounds to full extension, the rebound port slides in behind the DU bush in the seal head and seals off the port. It effectively gives you a nice and soft hydraulic top out. To shorten the stroke using a spacer, you'll ideally need the spacer to have a similar fit to the DU bush on the shaft, and the spacer needs to be secured to the seal head.
 

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