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  1. #1
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    Recommended tire pressure

    Setting up for fire roads and moderate sand/mud tracks, no jumps unless I screw up and go off a cliff then it doesn't matter. Front tire Wierwolf 2.5 and rear Nikon NBC 2.1 on a Specialized Endure. I'm 6' and weigh 200#, bike weighs 33#. Looking for recommended air pressure guidelines and suggest what I should initially set up with. Tanks.

  2. #2
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    Air pressure is really entirely terrain specific. You will be faster on smooth hardpacked fireroads at higher pressure, but you will be able to corner better and maintain traction in the loose stuff with lower tire pressure. I am a huge fan of the Stan's tubeless conversion kit, and run 25-30psi in a Nevegal 2.35/Ignitor combo. If you are not doing jumps, tubeless with low pressure will really improve traction on loose terrain (sand, rocks, etc.). If you are running tubes, I would run as low as you can without getting pinch flats. I can't get away with anything less than 35psi or so.

  3. #3
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    35 psi is where i always run at on my fastraks and they do decent. No pinches yet, but I wonder if I dropped it down to 30 psi how they would feel as I could use the extra traction now and then.

  4. #4
    NormalNorm
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    Quote Originally Posted by TXPhisher
    If you are running tubes, I would run as low as you can without getting pinch flats. I can't get away with anything less than 35psi or so.
    Yeah, I cant go below much below 35psi either. I also weigh 235lbs, which dont help. I cant say for the 2.5, but the 2.1....i'd try around 35-38psi as a starting point for the rear.

  5. #5
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    I'm about Norm's size and I can concur with his results. If I let me pressure drop to 30psi I will only be good if I don't huck stuff... I typically run 35-40psi.

  6. #6
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    Thanks for the replies

    I'm trying 40 today and see how it goes.

  7. #7
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    I've been 250lbs and ran 25psi in a Panaracer 2.4 up front, and around 30psi in the back. The key issue with a large tire is to get a correctly sized tube so that it isn't insanely thin when it comes up to volume. If you're running a 2.1-2.2 tube with a (real) 2.4 tire, a thorn puncture can quickly become a large hole that will not be sealed easily, and can shred the tube as its pressure drops.

    With 2.2 and 2.3 Specialized tires, I've been running around 28psi up front and 35-38 in the rear depending on the tire model. These have been tubeless. I was running around 30-32 in the rear but the Mavic Crossmax SL rim is a bit sensitive to rock strikes if there's any sort of puncture that has to be sealed and the pressure drops. I will get a little more tolerant rim next time so I can go back to 32psi or so (and hopefully be down to 220lbs at that time).
    1997 Specialized Stumpy Pro
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    2010 Specialized Roubaix Expert

  8. #8
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    im a bit unordodox, i use tubes and have them as hard as i can pump them, its true i get less traction but i seem to be able to deal with it, i went on a group ride today 14 other riders, i could hear a lot of sssssing of riders letting some air out when we got to the downhill parts, 6 riders got pinch flats, thats a record, i havent had a flat yet, perhaps because im 130 and try to take the best lines but hard tires seem to work for me so im sticking to my guns

  9. #9
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    I have always run 40psi in the tires because I prefer a slightly harsher ride and I like to let the suspension do the work.

    There is a scientific study on this that I happend to read. The study says that 28 psi is the optimum tire pressure for grip, rolling and tread life for a standard compound tire with an average weight of (I live in England so I don’t work kilos pounds or lbs) 12.5 stone if you live in England you can translate that but I’m an idiot so I cant. Below 20 and above 35 psi results in shorter tread life because of increased tread flexing which also causes higher rolling resistance at lower and higher psi.

    28 sounds very low, but I have tried it at 28 and though it felt to me that it was better I didn’t like the bouncy feel on “transit to the trail roads” so I keep it at 40 and then let it run down to about 32 over a few weeks.

    I think they may have failed to take into account other riding surfaces away from England cos I’ve had a look and it was carried out in Yorkshire which is rocks and relatively hard dirt.

    I hope this makes sense, I saw it in a magazine about 3 years ago.
    Last edited by EGF168; 12-24-2007 at 08:37 AM.

  10. #10
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    I'm just an old trail rider so I dont worry much about corner speed much. And since I weigh 210# I run high pressure. Between 45 and 50 lbs. I just cant stand carcass roll. lol

  11. #11
    Mud Boy
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    Fan of Stans Tubeless here too!

    I converted over to tubeless over 4 years ago. Conventional rim's and tires, converted with Stan's rimstrips and sealant. I'm 190lbs with gear-5"travel Stumpy FSR. I have 2.1 Roll X pro's and run 32psi front and usually 30-32 back . Yes, you do feel the tire flex at first. But once you get used to the almost limitless grip, the sensation is gone.

    I have a digital presta gauge, so I lock in the psi before every ride. Tire psi is every bit as critical as shock psi. The Stan's conversion is money well spent. The lower pressures yield AMAZING traction, and lower rolling resistence. Personally, I think the lower pressure's allow the suspension to work better. The bike isn't bouncing over every rock and root because of the big tire pressure.

    Stan's will virtually eliminate flat's too. I know little guys...like 135 lbs, that run low to mid twenties psi. It's a great bike mod, IMHO.

  12. #12
    Vaginatarian
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    I weigh 220 and on my weirwolves I run 32-34 with tubes, on the ust weirwolves I run 28
    on my 29er rampages I run 33 or so
    If I go lower I pinch flat & the usts burp so thats about it
    I ride rocks & roots new england, not really buff unless its a new trail

  13. #13
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    Fire roads I run 40psi and single track I have been playing around with different pressures. Seems like 30 in the rear and around 28 or so in the front. I to run Stans conversion kit and love it. No more flats...pinched, thorns or otherwise.

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