1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
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Thread: Air up or Down?

  1. #1
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    Air up or Down?

    I come from a world of 4x4 offroading where you air down when offroading. Does the same principle apply here?
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    pretty much.

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    What Slozomby said. Try around 35 psi, go up or down if you are or are not getting pinch flats with tubed tires.
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    Yep same mechanics, more of the tire's surface area is touching the terrain for more traction. I aired down to below 20 psi on tubed tires...big mistake. Can't wait to build my tubeless 26er

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    do you need "tubeless rim" for tubeless tires or can/do you modify existing wheels for this?
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    Quote Originally Posted by henmar77 View Post
    do you need "tubeless rim" for tubeless tires or can/do you modify existing wheels for this?
    Lots of methods to convert, do a search on "ghetto tubeless" for one of the most common.
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    OK i have went through 4 tubes since i started this thread and im tired of it. I think im going tubeless to see if i can avoid flats. the only thing i wondering about is what happens if the sealant fails and you get a flat on the trail, then what?
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    carry a spare? i use tubes, i air down to 20 or so for sand and really loose dirt. you just have to be aware of your tire pressure. i'm not going that low if i'm doing drops or hitting roots and stuff while going really fast... but even tubeless you can still bend a rim. if you're getting pinch flats with a relatively decent pressure, then you're probably riding too rough.. i carry a frame pump with me and i'll put some more air in when i get to some concrete or hard packed dirt that i know is going to last a while.

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    Quote Originally Posted by henmar77 View Post
    OK i have went through 4 tubes since i started this thread and im tired of it. I think im going tubeless to see if i can avoid flats. the only thing i wondering about is what happens if the sealant fails and you get a flat on the trail, then what?
    My friends who ride tubeless, they carry spare tubes. I imagine repairing a flat on the trail would get messy due to the sealant.

    If I were flatting four times in four days, I'd be tempted to nudge my pressure upwards just bit.

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    Quote Originally Posted by henmar77 View Post
    OK i have went through 4 tubes since i started this thread and im tired of it. I think im going tubeless to see if i can avoid flats. the only thing i wondering about is what happens if the sealant fails and you get a flat on the trail, then what?
    Do you know why you are getting flats? Every single time you get a flat you need to determine why it went flat and fix it. From thorns to your rim strip being off center to too low an air pressure can all be reasons your tire went flat.

    If you are running tubeless you carry a spare tube with you, just like if you were out on a ride with a tubed tire. You take the tubeless valve out and throw in your tube. Depending on the cause of the flat, sometimes you can just shake the sealant into the puncture and it will re-seal its self; you can just pump up the tire to the proper pressure afterwards if that happens.
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    [QUOTE=zebrahum;9524974]Do you know why you are getting flats? Every single time you get a flat you need to determine why it went flat and fix it. From thorns to your rim strip being off center to too low an air pressure can all be reasons your tire went flat.

    If you are running tubeless you carry a spare tube with you, just like if you were out on a ride with a tubed tire. You take the tubeless valve out and throw in your tube. Depending on the cause of the flat, sometimes you can just shake the sealant into the puncture and it will re-seal its self; yo

    ok maybe i didnt phrase that question right. Im more concerned about how your re seat the bead on the trail if the sealant doesnt fill the puncture before the tire goes flat. Will a hand pump reseat it or does it usually stay seated after a flat?
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    Quote Originally Posted by henmar77 View Post
    ok maybe i didnt phrase that question right. Im more concerned about how your re seat the bead on the trail if the sealant doesnt fill the puncture before the tire goes flat. Will a hand pump reseat it or does it usually stay seated after a flat?
    If it's just a puncture and you don't knock the bead off then it will usually just be able to be re-inflated. If it comes off the bead then most portable pumps can not reseat a bead. Some CO2 inflators should be able, but CO2 is said to cause issue with some sealants so I'm not sure that's any better of an option. Really, you just carry a tube and put that in there if you run into an issue which you can't inflate on the trail. I think you'll find that it happens far less frequently than you are imagining.
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    well I still have a couple of tubes left and i dont want to switch over until i get another wheelset. we shall see. thanks ...
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    outta curiousity what pressures were ya running on what tires?

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    I run 40psi in my tires and I never get flats... I would rather sacrifice a small amount of traction for reliability. Besides, you will get more rolling resistance from a 20psi tire than a 40psi tire. Some situations lower would be better, but the majority of the time 40psi seems fine.

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    i was around 40. got the last flat on the street last night. They are Kenda Nevegal tires with specialized tubes. Haven't taken out the tube yet to see the cause. I run around 35 on the trail. I got a flat on the trail on Saturday which was a weird one. We stopped to rest and while the bike was on the ground it started hissing. Took the tube off and it was a hole that looked almost like the tube was stretched until it was pulled apart. It was kinda like when tires on cars get old and start to crack. new tube though.
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    Quote Originally Posted by henmar77 View Post
    i was around 40. got the last flat on the street last night. They are Kenda Nevegal tires with specialized tubes. Haven't taken out the tube yet to see the cause. I run around 35 on the trail. I got a flat on the trail on Saturday which was a weird one. We stopped to rest and while the bike was on the ground it started hissing. Took the tube off and it was a hole that looked almost like the tube was stretched until it was pulled apart. It was kinda like when tires on cars get old and start to crack. new tube though.
    odd those arent rediculously low. check inside the rim for metal burs or foreign objects.

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    Quote Originally Posted by Slozomby View Post
    odd those arent rediculously low. check inside the rim for metal burs or foreign objects.
    This ^ ^ ^ ^ ^

    Also check the inside of the tire to see if there is any debris damaging the tube.

  19. #19
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    Quote Originally Posted by 006_007 View Post
    This ^ ^ ^ ^ ^

    Also check the inside of the tire to see if there is any debris damaging the tube.
    clean as can be.

    BTY love the Avatar. that commercial is cool.
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