Hi All,

I went to Hamstrley forest today and ahd a cracking time. Some well rough parts which are my favourite type of riding.

I run my rear shock as per the manual in terms of pressure (RP2). I have a travel indication ring and I noticed that although I really did abuse the bike today it was about 1.5cm from the bottom. Surely this means that I’m not using all of my travel.

Do you lot think that I should let some pressure out? It feels fine but it may feel better still if even more plush. I once read that you should aim to bottom out at least a couple of times per ride, is this right or just bollocks?

All opinions are very much welcome.

The “bottom out every ride” thing only makes sense if you only ever ride in one place.

But worth experimenting anyway- you can always put it back to how it was.

Have a play and let 5 psi out see how it feels. The lower the starting pressure though the more chance of the bike feeling soft under normal riding. Are you sure the shock is supposed to use it’s full body length, some don’t I think.

You shouldn’t be bottoming out at all if your suspension is set up correctly.

Are you sure the shock is supposed to use it’s full body length, some don’t I think.

I’m not jonba. Does anyone here know?

I do understand that it shouldn’t bottom out all the time but I do feel that my bike is producing about 100mm of travel and I want to get it all.

How much sag do you have?

If you let all the air out you’ll see how low the shock will go, and therefore where the “end” really is.

The general principle says you should bottom out your shock 2-3 times per ride, although thats difficult with an air shock. It does depend where you ride. If you consider maybe a 3-4 drop enough to bottom it out you’d need more air than riding general trails with roots and undulations in.

So a lot of it has to do with feel, Soft may equal more comfy yet more “movement” of the bike, harder is the opposite. You need to set it where you are comfortable.

To give you an example, my bike’s manual recommends 170psi for me. That gives me about 20% sag. Howver I’ve set mine to 160 PSI – nearer 30% sag as I like it to feel super-plush/moving. I (i have an rp23) ride with propedal on, set to 1. That supports it a little in the initial part of the stroke, but allows it to move well through the rest. I get about 85% of my travel on my normal ride.

Play about with the pressure 5psi at a time as mentioned above and see what you prefer.

Hi GHill, I’m running at 30% sag and the standard is between 25% and 33%, isn’t it?

Remember there is a difference between “bottoming” and “using all the travel”.

A shock “bottoms” when it hits the end bump stop still moving at a significant velocity, and with significant energy still left to absorb.

A shock “uses all it’s travel” when it reaches and just kisses the bump stop, but does so at a small and controllable velocity.

You feel a “bottom out” as a rider, you don’t feel “using all the travel”. Remember also that every time you hop or pick the bike up the shock lands on it’s top stop (rebound limiter) (because when the shock hits the stops with excess velocity the effective “rate” rapidly increases, and the loads are transfered directly to the bikes frame, and from their to your ass!)

Further to all that, you can use compression damping to effectively add a degree of velocity dependant travel control. Run the shock fairly plush(low pressure = low spring rate), giving you lots of sag (and hence traction at low speeds) but set a hard compression damping rate to limit how far it can travel as the shock velocity increases on large hits etc. For an air shock, the rate increases with compression travel, so actually hitting the hard end stops is actually quite difficult

Thanks very much you guys, I’m off to test tonight and I will let you know… 🙂

I had a Fuel EX9 from 2008 and used to run the shock with between 115-120psi max in it. The bike rode so sweet and plush. I weigh 12 1/2 stone and the sag would be around 35-40%.

I’m around 13stone and run the rp2 on my 2011 fuel ex8 at 205psi.

Riding in wales I use the full travel with the indicator a few mm from the bottom, riding elsewhere(Less rocky) I usually don’t get it much more than 10mm from full travel. Took a lot of playing with the pressures and rebound settings so I was happy. FYI i run the rebound 6 clicks from full fast.

With my trek ex8 I use these pressure settings

Roughly my body weight in kilograms for the forks, and my body weight in pounds for the rear shock. So 62kg = 62 psi or 130lbs = 130 psi.

This gives me the required sag, doesnt bottom out, and
doesnt feel spongy.

Does anyone else use a similar idea ?

I had a 2011 EX8 and ran 130psi rode great 11stone.