Eric

Anyone here have a bike with this rear shock? I just got my new stumpjumper FSR w/ propedal and I am having the hardest time setting it up. The ride seems so harsh compared to my old fox float on my 2003 kona. I have read that I should set the sag to at least 25% of the shock stroke compared to 1cm sag used on my old shock. This seems odd because I would think that I would be losing 25% of my 4" travel (3") as well as lowing my BB at least an inch. I am not a shock expert and I could be wrong about what sag actually does. Does the shock just need a break in period or something? Should I just go out and hit as much stuff as possible to work this thing? Any input would be greatly appreciated. Thanx

Maelstrom 

25% is average for a trail bike. I run my sag at around 33% give or take. Remember you aren't loosing the travel, just changing it to the negative side. There is nothing wrong with having that travel there in case you do drops and such. Forks also run a long sag in comparrison to their actual travel.

Since you are used to no sag you could run 20% as long as you won't overextend your travel and bind your spring

BlackDiamond

No you'll want to set up the sag correctly.

Maelstrom 

Oh and do you have too heavy a spring? And I forget can you change the progression on those bikes. I know you can on bighits?

Eric

I found something out interesting. I was pumping the shock up to say 165lbs and when I remove the pump, I hear air leaving. I was told that this was just air leaving the air tube attached to the pump. I then reconnect the pump to find out that I have about 145-150lbs in the shock. My sag appeared at about 25% though...hmmmmm? I then over pump the shock up to say 180lbs and it seems to work a little better on the little stuff and I have around 25% sag still. I then take the bike for a spin and play with the rebound a things seem a little better. Is there a break in period for these shocks? Should I go out and just work the thing? My pump is only a year old (Wrench Force Pump), I got with a 2003 Kona.

Eric

I don't have a coil over shock. Maybe you think I am talking about a front shock. It is a rear air shock (2004 stumpjumper FSR)

Maelstrom 

oops. Then I probaby can't help anymore. I only use coil and they react and feel very different

Structure0

It is my understanding that the the hiss of disconnect is, indeed, the air leaving the pump and tube. When you reconnect to the shock and take a new measurement, the pump and gauge fill from the air in the shock and thus, pressure being equal, the new measurement is slightly lower. What this means is that you don't have to "overfill" the shock to account for the disconnect. Just fill it to the desired pressure and disconnect. The check valve in the shock will insure that the pressure stays the way you set it. When you attach your shock pump next time and see "oh, my shock is down 10lbs" or whatever, it is because you have attached the pump and bled the shock to fill its chamber and the gauge, not because you lost pressure when you orignially disconnected.

That being said, I'm none too sure about ideal pressures. I've tried higher pressure slower rebound, lower pressure higher rebound, and mid-level on each and I'm not sure what is better. I'd like to see some more knowledgable tuners posting their settings... Me--one not-knowledgable tuner--I put my Fox RL at about 5lbs under body weight and set my damper at about two clicks faster than halfway. For "racing" I up the pressure by about 10lbs over body weight and set the rebound about midway.

Al.canoe

I don't do sag. I set the pressure at my dressed body weight plus the weight of my hydration pack to start with and trimmed from there. I wound up about 15 lbs more than that on our local trails. The bike is a 2003 Stumpjumper FSR Disc.


Al

BlackDiamond

Eric, you are right on track. Yes you new shock will require a break in period. Your ride should improve as all the bushings etc...settle in. Good luck!