Coil Shock for 2016 Stumpy

John Wh

Hi All,

I'm tempted to try out a coil on the rear of my Stumpy. I carry a bit of weight (15st8) and have read that coil springs are more progressive than air (with a slight weight penalty).

The problem is, according to the specs of my bike, the stock shot measurements are 197x47.6mm. I've had a look at a few coil shocks and I'm not sure what size I should be looking at as none of them match the measurements.

I've seen a few 200x50mm though, so I'm wondering if this is the right size and then the stroke length is altered somehow?

Anyone got any advice for me?

benpinnick

You have read wrong I am afraid. Coils offer exactly no progression whatsoever. None. Zip. Entirely linear. Not to say it wont be cool, but you wont get the effect you're thinking you will. It might still be good though. If you have enough progression in the shock curve, then a coil will let you run a heavy spring without the downsides of a high pressure air spring.

John Wh

Cheers for clarifying Ben, I think I've just got a bit confused with the terminology.

So, do you think they are more suited to heavier riders? I find that I have to run quite high pressure in the shock I have now. I'd like to try one, but not sure if I can get one in the correct size.

rockmonkeysc

Probably less suited to heavier riders. You will be constantly bottoming. I don't think you will get one to fit anyway because of the shock hardware that Specialized use.
A good air shock will work much better.
Bikes designed to run coil shocks have the progression in the linkage, bikes designed to run air shocks have a lot less progression in the linkage.

John Wh

Ah OK, cheers for the explanation Rockmonkey. I guess the best course of action would be to get the original shock Push tuned then?

The Rookie

Or set up right......depends what you have now and how you have set it up, also you have the option of changing air can volume to make it more or less progressive.

rockmonkeysc

A PUSH tune on the Fox float shock can improve it quite a lot. Options for upgrading are limited by the clevis hardware.
Can Creek shocks are available to fit it but they really don't work well on FSR bikes.

Antm81

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19696435#p19696435]John Wh[/url] wrote:

Ah OK, cheers for the explanation Rockmonkey. I guess the best course of action would be to get the original shock Push tuned then?

Looking at your thread on your stumpy it looks like you've got an evo model shock, unfortunately they can't be PUSH tuned, it's something I looked in to but after speaking to TF Tuned it's not possible.

John Wh

Cheers for all your feedback. I'm still finding my perfect setup with it, so maybe I'll be happy once it's sorted. I'll keep the stock shock for now and put the money towards a better fork (and some skills classes).

benpinnick

FIrst thing to do is to fill the thing with spacers, then see how she rides.

John Wh

Hi Ben,

Sorry to pester, but could you be a bit more specific?

Is it a similar thing to adding the bottomless tokens to a Rockshox fork, reducing air volume and enabling you to run lower pressure? It's something I'll look into (can't see it being too expensive to test at least).

benpinnick

Yes thats the deal. Basically glorified rubber bands. You let the air from the shock, unscrew the can, add said rubber bands inside and do it all back up again. That reduces the air volume which increases the progressive rate of the shock, meaning it will reach full travel (given the same input impact) without bottoming out harshly when running lower pressures than before.

rockmonkeysc

Newer shocks seem to all come with high volume air cans and the first thing everyone does is fill them with spacers to reduce the volume.

John Wh

It seems like change for the sake of it sometimes. I'll give the volume spacers a try. Looks like about £33 for a pack with float fluid, and easy enough to do looking at the videos.