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  1. #1
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    Another Tire PSI Question - About The Effects Of Running Too Low Of Pressure.

    I've read Many times about people running as low of PSI as possible for traction, etc. Today my PSI was low when I got out to the trails. I rode anyway since I had enough air to keep from pinching, but the tire seemed squishy side to side if I pushed on the fork or chain stay to the side. I ended up landing a jump a little off and my front tire washed out upon landing and I wiped out. A couple of times my front tire seemed to push out more than it should have in the turns. It was only my second time out this season, though, and I was riding harder than last time, so I'm not sure if it was that or because of the low PSI. When I checked my PSI back at home It was ~20. Will pressure that low give you more traction or is it so low that it may have been why my front tire seemed to have less traction than it should have?
    90 Miyata 914 with full Dura-Ace
    74 Ellis-Briggs, full butted 531
    80s Cierra Professional 5000, Tange Champion 2 and Shimano 600
    2011 New Belgium Cruiser
    Fetish Cycles "Discipline" built up with DJ2 fork and Shimano XTR, LX, Avid BB7.

    Quote Originally Posted by scyclops View Post
    Oh yeah, sure, what if everyone thought that way? Then internet forums would merely be places where rational people exchange useful information and ideas - instead of the chaotic, emotionally-charged circuses that they are.

  2. #2
    "I got a fever..." dminor's Avatar
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    That depends on the tire itself. A 2-ply DH casing tire will benefit from low pressures like that. But the sidewalls on single-wall folding-bead tires run real low can buckle or deform, which negates your traction and compromises handling.

    Quote Originally Posted by Clutch
    Please allow me to adjust my pants / So that I may dance the good-time dance / And put the onlookers and innocent bystanders into a trance

  3. #3
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    Awesome. Thanks. I'm running the "Race" version of WTB MotoRaptors, which I'm pretty certain fall into the second category.
    90 Miyata 914 with full Dura-Ace
    74 Ellis-Briggs, full butted 531
    80s Cierra Professional 5000, Tange Champion 2 and Shimano 600
    2011 New Belgium Cruiser
    Fetish Cycles "Discipline" built up with DJ2 fork and Shimano XTR, LX, Avid BB7.

    Quote Originally Posted by scyclops View Post
    Oh yeah, sure, what if everyone thought that way? Then internet forums would merely be places where rational people exchange useful information and ideas - instead of the chaotic, emotionally-charged circuses that they are.

  4. #4
    Senior Member rumrunn6's Avatar
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    judge pressure by performance. you didn't like the performance of the pressure you used today so go higher next time. soon you will know what works best for you. I did the same with studded snow tires while bike commuting through the winter. some days I liked max pressure, other days I let 2lbs out.
    cycling is like baseball ~ it doesn't take much to make it interesting

  5. #5
    one less horse cryptid01's Avatar
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    Quote Originally Posted by dminor View Post
    But the sidewalls on single-wall folding-bead tires run real low can buckle or deform, which negates your traction and compromises handling.
    ...and also makes you ruin your shorts when it rolls over during hard cornering.

  6. #6
    "I got a fever..." dminor's Avatar
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    Quote Originally Posted by cryptid01 View Post
    ...and also makes you ruin your shorts when it rolls over during hard cornering.
    Yeah and that too.

    Quote Originally Posted by Clutch
    Please allow me to adjust my pants / So that I may dance the good-time dance / And put the onlookers and innocent bystanders into a trance

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