Tire Pressure

[kevine3]

As of right now I am running Kenda Small Block Eights and I’m wondering what are some good tire pressures that other people have found.

[8valvegrowl]

Tire pressure is very dependent on a bunch of things, i.e. your weight, sidewall stiffness, UST Tubeless vs Stan’s Tubeless vs tubes, terrain/trail conditions, and just plain ol’ personal preference.

Me, I like to run things on the soft side, usually between 18-30psi depending on the tire and terrain. I find that a softer tire is often faster in that it conforms well to the rocks and roots instead of rebounding off them. Grip is better, and drifts are more progressive. I run high volume tires with Stan’s NoTubes and it’s very forgiving at low pressures. You just don’t want to be inmpacting your rim on square edge hits and the like.

I say experiment with pressures, but be sure to be pretty methodical about it.

[ltud]

I try to run my tires as low as possible, but as pointed out above, it’s dependent on so many things. My method is not super methodical, but it’s super easy.

I tend to pick a starting point a little higher pressure than I expect to end up with, and then work down from there. I’ll ride for a bit, making sure to hit a few hard edged obstacles at speed, and if I don’t hit my rims, I let some air out – easy with Presta valves. I repeat this process until I feel/hear my rims starting to strike. Then I add a bit of air. It’s a little risky if you run soft tire or thin tubes, but I’ve never damaged a tire or tube doing this and my rims are still solid. I might not do it this way if I had nicer rims lol.

[Corey Maddocks ✓ supporter]

I saw an interesting formula on the Stan’s NoTubes website:
rider weight (with gear) divided by 7
+1 psi for the rear
-1 psi for the front

That puts me at 29 for the rear and 27 for the front, which is about what I’ve been running for several years, without knowing that formula.

i’m currently running irc trailbears a little heavy but i am not a pro or racer so i don’t worry about that but i run 29-30 rear 26-27 front. weight 180. i have never had any issues at that pressure. and don’t forget to let r rip.

[ltud]

"maddslacker" wrote

I saw an interesting formula on the Stan’s NoTubes website:
rider weight (with gear) divided by 7
+1 psi for the rear
-1 psi for the front

That puts me at 29 for the rear and 27 for the front, which is about what I’ve been running for several years, without knowing that formula.

Interesting formula, and a good starting point. It doesn’t factor in tire volume though. I find that using my method described above, I end up putting different amounts of air in different sized tires.

I also tend to put a little more air in the front than the back (unlike on my motorbike) as I want the back to deform for traction and I want the front to stay relatively round. My ideas may be out of whack though.

[fat_billy]

Due to my rotund personage I run a lot of air pressure. One of the trails I ride a lot is rock city. The rocks are loose, planted, sharp, pointy ect. Too little air makes it pinch city. I run Michelin folding tires and they are thin and probably helping the pinch problem. They are light and work great even with high pressure (40-50 psi). One advantage of higher pressure is less rolling resistance. It seems that all the new style tires have less depth of tread so softer may be better. I do know in muddy and slick conditions a higher pressure will help the tire reach down better to where the traction is. My tires do deform in the contact patch( due to weight) and grip well. I demoed a 29er the other day with the "new" style tires and I ran 45 psi and the tires worked fine. I see people all the time with low pressure in their tires doing fine. I pumped up a roadbike tire today and 120 psi made my tire pressure seem low enough. My bike is a hardtail and pinching is easy with out higher pressure. I think I could get away with lower pressure with rear suspension. Next time I get tires I’ll look into anti pinch models. 😄 Later,

[bmakabayan]

the smaller the tire size the higher PSI, the larger the tire size the lower PSI.

[Dwhitt1981]

I’m running small block 8 also (which I love) and run around 38 psi in mine any more and and it kills my back. Also I weigh 230 lbs.

[Dustin Gaddis]

Another data point:

WEIGHT: 170lbs
BIKE: 29er hardtail
FRONT TIRE: 2.0" wide, 20psi
REAR TIRE: 2.0" wide, 23psi

I’m tubeless tho.

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