Suntour Raidon issues

[Benji Mtb]

In January this year I purchased a ragley marley 2.0 from chain reaction cycles. I was very pleased with the bike but the sr Suntour Raidons it came with act very strance. The rebound is extremely slow at the fastest setting and the fork seems to have no bounce. I have tried adjusting the air multiple times and have it set to around 20% sag ( the recommended amount )

With the recommended amount of sag the fork doesn't compress, with more air the fork is rock solid and with less when compressed the fork does not come back up.

I've heard of using volume spacers in the fork, what do they do?

Please leave any suggestions
Thanks

[Duck!]

Sounds like you have a damper problem, not a spring problem. Volume spacers - if they're even available for the Raidon fork - will not help you.

What do volume spacers do? As the name suggests, they alter the volume of the air spring chamber, which changes the compression ratio of the spring. If the air champber volume is reduced, x suspension travel uses a greater percentage of the chamber depth, which increases the rate of air compression in the chamber, making it more resistant to further compression..... But as I said, that's not your problem (plus as far as I'm aware, no Suntour forks have volume spacer compatibility unless they've changed very recently).

Your problem is in the other side of the fork, the damper. This controls the speed at which the fork can compress and extend. The damper is valved in such a way as to only allow the oil to flow one way through the system; compression opens one valve to allow oil to transfer to different chambers. When the fork is no longer in compression, that valve shuts off, forcing the oil to return through a different set of valves on the rebound stroke. Poor fork speed indicates either the damper valves are poorly adjusted, or simply the oil is too thick and cannot flow properly through the damper.

One way or another, you need a damper service.