Psi?

Discussion in 'Mountain Biking' started by Team01, May 6, 2009.

  1. Team01

    Team01 Guest

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    Wondering what sort of PSI you guys are running on average for trail riding?
     
  2. littleblackxj

    littleblackxj New Member

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    I run about 30psi. I'm not sure if that's considered high or low, but I always like stiff tires.
     

  3. BigDumbBear

    BigDumbBear New Member

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    Depends on your weight, terrain, style of riding, and conditions. I'm roughly 250 pounds and ride some fairly rocky-rooty terrain so I run about 50 psi front and around 60 psi rear to help prevent pinch-flats around every corner. The higher pressure also causes traction problems on steep hill climbs, but a little walking up a bad hill is better than a lot of walking to the car with a flat.
     
  4. beachbuggy

    beachbuggy New Member

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    I run 30 psi wet or dry. the tubeless tire is more forgiving at lower pressures. no pinch flat and lots of traction. less roll resistance too.
     
  5. Doc

    Doc Guest

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    IIRC the last time I filled em up I set it at 32, seems to be a good average for me.
     
  6. Dstompe

    Dstompe New Member

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    I usually run 35-40
     
  7. powderbock

    powderbock Guest

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    I tend to run around 35-40. Have only had 1 pinch flat in the past 5 years.
     
  8. tetonmtnbiker

    tetonmtnbiker Guest

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    I run 35 to 40 if I am using tubes or racing. If I am using tubless (not worried about pinch flats) and not worried about speed I run around 25 for maximum grip and feel.
     
  9. GrizzlyBear67

    GrizzlyBear67 Member

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    With that response I'd say you're not that dumb! I agree with everything you said and would add two points. Rim width and tire size. My new felt came with 2.2's and really skinny disc specific rims. I'm used to running 1.95's on the width of a Sun Rhino Lite or Mavic 261. I noticed that with the new combination I'm putting in only 45lbs. When running the wider rims with 1.95's I'm like you-up in the 50 to 60 lb range. With thinner rims and bigger tires you'll have less contact patch even when running the same pressure that you're used to, making your ride alot more sketchy.

    So to make it simple, I'd agree with my Bear cousin and say your weight will be the first factor then you can get as technical as you want from there. If you're over 200lbs than you will more than likely want to start at 45lbs but probably won't go beyond 60lbs offroad.
     
  10. BigDumbBear

    BigDumbBear New Member

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    HAHA, yeah... I'm really not that dumb. I just look that way. I do have semi-narrow rims, but I'm also limited to about 1.95 tires on the back of my Mt. Fuji Pro. It has a very close rear triangle. I'd love to be able to run a 2.35 in the rear but there is no chance of clearance. I am contemplating trying out the tubeless tires and lower psi to see what that does for me though.
     
  11. GrizzlyBear67

    GrizzlyBear67 Member

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    You'll notice the added rolling resistance really fast. Remember the old smoke 2.1? I tried running those front and rear and it felt like I was driving a monster truck...not that I ever have. 2.35 would be great if you are doing a lot of DH but isn't your bike an XC? If you're like me-a wanna be xc rider, I'd stick with the 1.95. I'm going back when my 2.2's wear out.

    So are you saying that with tubeless you can run lower pressures with the same tire floatation? That's interesting. I haven't done very much research into them, I just slime and go...
     
  12. BigDumbBear

    BigDumbBear New Member

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    I am more of a cross country rider... My logic behind running a wider rear tire is to get more traction on the hill climbs. I have a lot of problems with tire spin in the crux of a steep climb. The tubeless tire allow you to run lower pressures with no real chance of a pinch flat. I'm not sure if I am gonna make the switch or not. Just another idea I'm checking into. Hopefully I can continue my recent weight-loss trend and get my weight down to a point that I won't need to change the tire setup. I'm down 12 pounds in the last few weeks... Only about 30 pounds to go. lol.
     
  13. hophead

    hophead New Member Tavern Member

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    I'm running on average around 30 to 35 psi depending on trail conditions and which bike I'm riding. I'm around 190 and my mtn bike tires are all 26" between 2.1-2.5". I go to the high end if the trails are very rocky to prevent pinch flats, sometimes up to 40 psi.
     
  14. Neuner

    Neuner New Member

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    I agree. I'm 175lbs and use 2.1" width for XC. If it's a fast packed dirt I will run between 35 & 40psi for speed. If it's slower technical with a lot of rocks & roots I'll drop down to 20-25psi for added grip and cushion.

    When I hit chatty rock (common in Missouri) at higher speeds with high psi, it gets squirrelly and loose but then if I ride wrong with a low psi & hit something hard at a fast pace like the edge of a rock, I'll get a pinched flat. So you really need to try it out and feel what you are comfortable with and how you ride.
     
    Last edited: Jun 9, 2009