Hi Mel!
Since graduating from hardtail to a full suspension Giant Trance 2 a couple years ago, I can't seem to find the right balance between tire and rear shock pressure. Our group does mostly XC riding on a fairly technical single track with lotsa stumps, rocks, roots and a couple short but nasty loose rocky climbs. On my hardtail I found that 2/3 "normal" tire pressure worked great. With my new bike I'm finding I either need more tire pressure or I need to boost the shock pressure about 20psi higher than what is spec'ed for my weight. Otherwise I have ratchet way too often to keep myself from burying my cranks in the dirt. The problem is I just can't seem to find the right pressure balance. Any suggestions? Thanks!

Hi Toby,

A dual suspension always behaves differently from a hardtail. My Fourstroke 01 is designed with a higher bb so that with the sag in the suspension you don't end up too low and bashing the cranks. Having not ridden a Trance I dunno what is happening exactly in your case. I would say that if you are hitting your cranks you are likely getting too much travel in the rear suspension. Using your tire pressure for traction would be your first approach. Depending on the tire you can decide how much air... less being required since you do have rear suspension to absorb impact. It sounds like you do have to go above the spec for the rear shock but I would also have it checked to ensure it isn't leaking air or having problems of some sort.

Too little tire pressure can add a lot of rolling resistance and too little rear shock pressure can sap the power from your pedal stroke. Maybe you need more of both?

Not really sure unless I actually witnessed the setup but those are my thoughts....

Hi again Mel!
Definitely more of both was the solution. I went for an absolutely awesome ride this evening. I dialed up the rear shock pressure 25lbs above spec. and pumped up my tires to 50lbs. Now I'm riding with signifigantly less sag. I really like that! I also played around with the rebound. I used to have it set far too slow. Now my bike reacts the way I like. Thanks Mel!!

Riding with your tires at 50 psi means you are getting absolutely no benefit from the tread. WAAAAAAY to much air!!

If you are riding tubeless, assuming you are riding offroad, you can ride anywhere from 20-40 psi depending on your weight and the terrain.

If you are riding tubes, maybe 28-45ish psi?

Given you are riding a duallie, even if you are riding tubes, the lower end of the spectrum is better but practicing to see what is the limit before pinch flats start is a good idea. It is important to learn what pressure you can run as it makes such a difference for cornering and traction. I would guess 50psi is bad for both of these.

Let some air out!!!

If you flat instantly, I owe you a tube but I still believe the ride pre-flat will be better

M

Yeah, I can see your point about traction Mel. The roots were pretty slippery yesterday! I used to ride with my tires at 35 - 40 psi and found them a little too soft, and yes, I did end up with a pinch flat on the first lap of an enduro last September. I weigh around 190lbs so I'm guessing tire pressure has to be somewhat relative to rider weight. I'll try backing it down a bit a see what happens next ride. Thanks again!
BTW that Fourstroke is one drool-worthy looking rig! You must love it!

Post edited by: Toby, at: 2007/04/23 13:07

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