I’ve just stuck an RP2 on my MX. At 12 stone, I need to pump it up to about 230psi to stop the shock bottoming all the time. But this means that I lose all my sag and the propedal switch effectively just becomes a lock out. Which doesn’t seem ideal.

What sort of pressures are other people running in Fox shocks on Prophets? And will I damage the shock by bottoming it out all the time?

Cheers!

don’t run a Fox so can’t tell you my pressures, BUT what kind of aircan do you have on your RP2?

I imagine it would say if it’s a high volume verion on the can itself, as the High volume can’s aren’t supposed to suit the type of suspension that the prophet has (linear?).

worth checking out, as it doesn’t sound at all right at the moment.

It’s a low volume can. The high volume one came off after one ride…

The Prophet has a regressive suspension design i.e. the further into the travel you go, the easier it moves through its travel. I believe all OEM shocks were valved accordingly. If you use a regular shock it may will blow through its travel very easily. I’ve used a Swinger 4-way and have used the SPV chamber volume adjustment to counteract the bottom out tendancy.

That seems wrong for someone who is 12 stone.

You should probably be at about 150ish psi (which should give you about the right amount of sag).

If it bottoms all the time when the sag is right you need more compression damping (assuming the shock is working properly).
What is the ‘compression tune’ on your shock (should say on a sticker)?

It sounds like either the shock is dodgy or you are riding it really hard and need more compression damping – send to mojo/tft for tuning.

I hated my Prophet with an air can and fitted a Vanilla RC – perfect!

The Prophet has a regressive suspension design i.e. the further into the travel you go, the easier it moves through its travel

You mean falling rate?

You mean falling rate?

Yup, the opposite to progressive or rising rate.

Cool, I’ve not heard that terminology before.

p.s. as dusty lilac has mentioned, the prophet has a falling rate design to counter rising rate air shocks and give a linear stroke (so large air cans are a no, as you’ve found out!).
This should work fine if the compression damping is correct, but perhaps isn’t the best design if you like big drops etc.

165psi at 13 stone here on an rp23 with standard volume can

I’m 12st and i have 170psi in my Pushed RP3 and like to run it on the softer side. I do bottom it out sometimes but only on fairly decent jumps and drops, never on ‘normal’ trail riding. I can’t see that bottoming it out all the time will do it any favours.

I’m guessing there’s something up with it or at least needs a good service?

I’m 12.5 stone and have around 160psi in the basic Fox Float R on my Prophet 2.

15.5 stone and 170psi on my RP2, never bottoms out but comes close which seems perfect to me.

Cheers guys. Not sure what to do. I spoke to TF Tuned and they reckon there’s not a lot that can be done to increase the compression damping. I’ll probably just run it at that pressure and put up with it (I’m only bottoming off jumps and drops, not during general riding).

The other option is to flog it and stick my knackered old rockshox pearl 2 back on…

I’ve got a PUSHed RP23 on my MX & Tim F recommended running it at around 200PSI (for 13st10 rider) which seems to be OK though its not great on small stuff. PUSH did recommend fitting a DHX bottom out bumper in the shock to help compensate for the falling rate when at the end of the shocks travel. Its fine really but not as nice as the PUSHed coil shock on my 224!

Brown – have you tried letting some pressure out and riding it with the ProPedal on? My RP23’d Prophet rides better (on everything) with the ProPedal turned on. ProPedal is not just to counteract pedalling-bob, it’s also a bit like low-speed compression damping all the way through the shock’s stroke.