Too much Compression on Rear shock?

freddy-b

Hey,

I Recently bought a Specialized Stumpjumper FSR expert.

I notice that when i bunny hop the fork compresses itself a lot, i can see that with the o ring that the shock has on it.

It leaves a something like a 0.3cm distance from the end of the shock. And i feel a that the shock hits the end.

The sag is at 25% of the shock.

i weigh 53Kg

What should i do?

Thanks,

nicklouse

Ride it.

Sag set in the normal riding position/attack position?

As do you mean shock or fork? You mention both.

And you do not mean compression as that controlls the speed it compresses thorough it's travel not how much travel it moves.

diddyfunk

I have a Stumpy Evo and although I had the Sag setup correctly I still needed to put in a few extra PSI.

Best thing to do is have a play and take a shock pump out with you and see what works for you.

I'm still playing!

freddy-b

nicklouse wrote:

Ride it.

Sag set in the normal riding position/attack position?

As do you mean shock or fork? You mention both.

And you do not mean compression as that controlls the speed it compresses thorough it's travel not how much travel it moves.

sorry, i mean the shock..

and yes sag is set at 25% the normal position.

cooldad

Try experimenting with the sag - around 20% and see how it feels.
But suspension should bottom now and again, or it's not all being used, and if the bike is handling properly it doesn't matter what it 'looks' like.

delcol

stick a real shock on it something with a coil spring....

diy

I believe this model is fitted with brain fade. This is similar to propedal, you can make the shock firmer by turning the blue dial on the remote "brain" unit clockwise, the alternative is to up the pressure in the can and tune the fade the otherway. I'd start with a firmer brain, but if it gets unresponsive you might want to try the reverse.

bails87

freddy-b wrote:

i weigh 53Kg

What should i do?

Eat more pies & drink more beer!

Stu Coops

If it's a Fox Shock check the info that is printed on the shock as the Velocity Tune may say L if it does this maybe the problem which means the shock has been set up light, if this is the case as on my mates bike you can either increase the PSI or Mojo can change the Velocity Tune to M obviously Medium for about £35

Giant work with Fox and do this Rear Shock set up on some of there bikes and I don't understand why because it's always to soft for average weight riders in the UK. My mate rang Mojo by the way and they said just increase the pressure, the common understanding is roughly 1PSI for every 1LB you weigh then just minor adjusting needed but he has put in 230PSI and weighs only 175LBs but the bike is fine now

nicklouse

Stu Coops wrote:

the common understanding is roughly 1PSI for every 1LB you weigh

sorry but total rubbish. a Common Missunderstanding is more acurate

just add what you need to get the sag you want and then adjust.

give same weight and same shock a bike with a 1:1 ratio suspension will not have the same pressure as a 2:1 or a 3:1 suspension system.

Stu Coops

nicklouse wrote:

Stu Coops wrote:

the common understanding is roughly 1PSI for every 1LB you weigh

sorry but total rubbish. a Common Missunderstanding is more acurate

just add what you need to get the sag you want and then adjust.

give same weight and same shock a bike with a 1:1 ratio suspension will not have the same pressure as a 2:1 or a 3:1 suspension system.

Couldn't agree with you more as I was led to believe this until my mate stuck 230 PSI in his, so no dispute from me on this one.

diy

By pure coincidence it comes up to within 10psi of the right answer for me.

bails87

diy wrote:

By pure coincidence it comes up to within 10psi of the right answer for me.

As nicklouse said above, (and for the benefit of anyone else) this really will be pure coincidence. Different bikes have massively different ratios of wheel:shock movement.

freddy-b

nicklouse wrote:

Stu Coops wrote:

the common understanding is roughly 1PSI for every 1LB you weigh

sorry but total rubbish. a Common Missunderstanding is more acurate

just add what you need to get the sag you want and then adjust.

give same weight and same shock a bike with a 1:1 ratio suspension will not have the same pressure as a 2:1 or a 3:1 suspension system.

Sorry.. but i cant really understand this..

can you give me an example?

cooldad

Leverage. If the leverage ratio is 2:1 the shock would need be firmer than 1:1.
It's not something you have to think about. Just set up your bike for you.