Advertise on Bikeforums.net



User Tag List

Results 1 to 16 of 16
  1. #1
    Commie
    Join Date
    Jun 2008
    Location
    Las Vegas
    My Bikes
    Trek 7.3 FX, old Haro(92)
    Posts
    278
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    ok whats going on here

    I switched over to 700x28C tire a few weeks ago. Im on my second flat already, but both times the hole where the leak starts was around the valve stem. I made sure to put the tube/tire on properly after looking up the method on a website. I dont understand why it tears near the valve. The sidewall states 120PSI max, so i put anywhere from 115-120 PSI(going by the gauge on the pump, topeak Joeblow sport)

    the tubes are bontrager 700x28-32c -1/8-1/4

    the wheel is a Bontrager camino 622-32 wheel

    this last flat happned over night, i rode yesterday morning several miles, came home and today the tire was flat when i went to go ride...

    is it getting pinched? should i not inflate so high, do i need a different wheel?

    thanks

  2. #2
    Senior Member BCRider's Avatar
    Join Date
    Mar 2008
    Location
    The 'Wack, BC, Canada
    My Bikes
    Norco (2), Miyata, Canondale, Soma, Redline
    Posts
    5,410
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Sounds like a bad batch of tubes to me.

    I'd try a different brand at least for the near future just so you avoid this issue.
    Model airplanes are cool too!.....

  3. #3
    Commie
    Join Date
    Jun 2008
    Location
    Las Vegas
    My Bikes
    Trek 7.3 FX, old Haro(92)
    Posts
    278
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    i hope that is all it is. I will keep my speed lower for a couple of weeks just in case, dont want to have a blow out going 25+

  4. #4
    Senior Member
    Join Date
    Sep 2007
    Posts
    835
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Is your tube touching metal where the valve goes through the rim?

    If so, cover the metal with something.

  5. #5
    Senior Member Matt Gaunt's Avatar
    Join Date
    Oct 2004
    Location
    London, UK
    Posts
    2,214
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by SPlKE View Post
    Is your tube touching metal where the valve goes through the rim?

    If so, cover the metal with something.
    +1 for a check. Also, try filing any sharp edges off the hole in the rim. Having said that, if you weren't experiencing problems before switching, it does sound like either a change in technique on your part or faulty tubes may be to blame.
    Matt
    2010 Kinesis Decade Convert2 Alloy fixie, Miche, Sora Pics soon...
    2008 Kinesis RC2 Scandium/Carbon Road, Ultegra, Ksyrium Elites Pics
    2007 Kinesis Pha5e Scandium hardtail, XT, Revelations, Rockets, M4s, Mavics Pics
    2005 Kinesis RC Scandium/Carbon Road, Ultegra, Ksyrium SLs Pics
    1996 Raleigh Max Steel, Deore XT, SRAM Attack shifters, homemade wheels Pics

  6. #6
    Senior Member mike's Avatar
    Join Date
    Jul 2000
    Location
    Snowy midwest
    Posts
    5,392
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Of course, check the condition of your rim tape and check the hole for sharp edges.

    Next, when you install the tube/tire, be sure to inflate about 30%, then push the stem back into the tire (push the stem back into the rim hole so it goes into the tire, but not so much that the stem falls inside the tire).

    This assures that the tube around the valve is seated properly inside the tire and helps make sure there are no tube wrinkles around the stem.

    I assume that you are also making sure the valve is 90 degrees to the rim and not laying cattywhompus sideways.
    Mike

  7. #7
    Senior Member Matt Gaunt's Avatar
    Join Date
    Oct 2004
    Location
    London, UK
    Posts
    2,214
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by mike View Post
    Of course, check the condition of your rim tape and check the hole for sharp edges.

    Next, when you install the tube/tire, be sure to inflate about 30%, then push the stem back into the tire (push the stem back into the rim hole so it goes into the tire, but not so much that the stem falls inside the tire).

    This assures that the tube around the valve is seated properly inside the tire and helps make sure there are no tube wrinkles around the stem.

    I assume that you are also making sure the valve is 90 degrees to the rim and not laying cattywhompus sideways.
    What's that now?

    edit: nice vocab.
    Last edited by Matt Gaunt; 08-06-08 at 03:09 AM. Reason: I used google
    Matt
    2010 Kinesis Decade Convert2 Alloy fixie, Miche, Sora Pics soon...
    2008 Kinesis RC2 Scandium/Carbon Road, Ultegra, Ksyrium Elites Pics
    2007 Kinesis Pha5e Scandium hardtail, XT, Revelations, Rockets, M4s, Mavics Pics
    2005 Kinesis RC Scandium/Carbon Road, Ultegra, Ksyrium SLs Pics
    1996 Raleigh Max Steel, Deore XT, SRAM Attack shifters, homemade wheels Pics

  8. #8
    Commie
    Join Date
    Jun 2008
    Location
    Las Vegas
    My Bikes
    Trek 7.3 FX, old Haro(92)
    Posts
    278
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    thanks all, will try suggestions.

  9. #9
    Senior Member oldbobcat's Avatar
    Join Date
    Jul 2005
    Location
    Boulder County, CO
    My Bikes
    '79 Gios, '80 Masi, '06 Felt, early '60s Frejus
    Posts
    2,455
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    We sell Bontrager and had a run of bad tubes in that same size. Punctured five tubes on a customer's bike, all where the valve stem is bonded to the tube, before we decided to try the next smaller size. Problem solved.

  10. #10
    Commie
    Join Date
    Jun 2008
    Location
    Las Vegas
    My Bikes
    Trek 7.3 FX, old Haro(92)
    Posts
    278
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    smaller size as in 48mm valve stem or 36mm? My lbs only stocks 48mm. I should find a new tube. So far i have not had a flat with 40+ miles on the new tube i replaced a few days ago. But i have a feeling in few days i will wake up with one.

    what are other brands of tube that are good quality, that isnt over 7 bucks

    I would like to mention i rode on the 32c tires for about 6 weeks without an issue at all, i kept them at 85 psi at all times. A week after i switched over to the bontrager 28c tire, now i have these slices near the valve..twice now..and a third is probably coming up soon, hopefully not at high speed.*knock on wood*
    Last edited by TalkingHead; 08-07-08 at 01:56 AM.

  11. #11
    Senior Member Matt Gaunt's Avatar
    Join Date
    Oct 2004
    Location
    London, UK
    Posts
    2,214
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by TalkingHead View Post
    smaller size as in 48mm valve stem or 36mm? My lbs only stocks 48mm. I should find a new tube. So far i have not had a flat with 40+ miles on the new tube i replaced a few days ago. But i have a feeling in few days i will wake up with one.

    what are other brands of tube that are good quality, that isnt over 7 bucks

    I would like to mention i rode on the 32c tires for about 6 weeks without an issue at all, i kept them at 85 psi at all times. A week after i switched over to the bontrager 28c tire, now i have these slices near the valve..twice now..and a third is probably coming up soon, hopefully not at high speed.*knock on wood*
    Michelin AirComp. Dunno how much they retail for in the US but for 4 over here they're fantastic.
    Matt
    2010 Kinesis Decade Convert2 Alloy fixie, Miche, Sora Pics soon...
    2008 Kinesis RC2 Scandium/Carbon Road, Ultegra, Ksyrium Elites Pics
    2007 Kinesis Pha5e Scandium hardtail, XT, Revelations, Rockets, M4s, Mavics Pics
    2005 Kinesis RC Scandium/Carbon Road, Ultegra, Ksyrium SLs Pics
    1996 Raleigh Max Steel, Deore XT, SRAM Attack shifters, homemade wheels Pics

  12. #12
    cab horn
    Join Date
    Jun 2004
    Location
    Toronto
    My Bikes
    1987 Bianchi Campione
    Posts
    28,292
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    What do you mean by "good quality"? A $4 MSRP kenda tube holds air perfectly fine.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  13. #13
    Senior Member oldbobcat's Avatar
    Join Date
    Jul 2005
    Location
    Boulder County, CO
    My Bikes
    '79 Gios, '80 Masi, '06 Felt, early '60s Frejus
    Posts
    2,455
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by TalkingHead View Post
    smaller size as in 48mm valve stem or 36mm?
    Sorry for not being more specific. Smaller as in 27x7/8-1", or 700cx20-25. These are actually easier to work with under a slightly wider tire, and the smaller cross section means they just stretch a little more.

    All road presta tubes that we stock have 48mm stems.

    I've personally had good luck with CST lightweight tubes purchased on an ebay store called nicebiketires.

  14. #14
    Senior Member DannoXYZ's Avatar
    Join Date
    Jul 2005
    Location
    Saratoga, CA
    Posts
    11,495
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Don't tighten down the valve-stem nut too far, just enough so you don't lose the stem into the tyre when installing the pump. Also only use floor-pump, no hand pumps allowed.

  15. #15
    deep stuff brucewiley's Avatar
    Join Date
    Jun 2007
    Location
    Nampa, ID
    My Bikes
    Road, Touring, Mountain Bike
    Posts
    250
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Leave the stem nut off, I haven't run any for years since I discovered the reason I kept busting stems was from tightening the nut because it rattled. Think of all the weight you save too!

  16. #16
    Your mom
    Join Date
    Aug 2006
    Posts
    2,546
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Are you inflating with a mini-pump? I killed tubes with mine for years before I invested in a stand pump. Haven't had a problem since.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •