Advertise on Bikeforums.net



User Tag List

Results 1 to 5 of 5
  1. #1
    Hills hurt.. Couches kill RacerOne's Avatar
    Join Date
    Jun 2008
    Location
    Brazil, IN
    My Bikes
    1991 Specialized Sirrus Triple, 2010 Trek Madone 6.5 Project One, 2012 Cannondale Caad10, 2013 Trek Crockett
    Posts
    3,361
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)

    Flats at the valve stem

    I've had three flats on my cyclocross bike in the past couple of weeks, all of them at the valve stem. At first I thought it was the cheap rim strip that came with the "Vuelta XRP Cross for Disc or Rim DoubleWall, black anodized" wheels allowing contact between the stem hole and the tube / stem junction. I replaced it with quality tape but low and behold I flatted in the same way yesterday.

    Basically it looks like they are getting cut right at the base where the stem joins the tube. I'm running about 35#'s in my 34mm tires with Kenda Q 27-32 tubes. When I put the tape on I checked for sharp edges but didn't notice anything out of the ordinary.. any suggestion?

  2. #2
    Senior Member CACycling's Avatar
    Join Date
    Feb 2008
    Location
    Oxnard, CA
    My Bikes
    '08 Fuji Roubaix RC; '07 Schwinn Le Tour GS; '92 Diamond Back Ascent EX
    Posts
    4,441
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It is usually either the rim (check the valve hole carefully for burrs or other sharp edges) or operator error (being too rough on the stem when inflating).

  3. #3
    Senior Member
    Join Date
    May 2008
    Posts
    1,215
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Grab one of the flatted tubes, it's basically garbage now anyways. Chop the valve stem out of the tube so you have about a square inch of rubber with the valve stem in the middle. Rip the stem out and you will be left with a square patch with a little circular hole. Place this square patch over your new tube's valve stem and it will protect against future valve stem damage.

  4. #4
    2 Old 2 B New B spudston's Avatar
    Join Date
    Mar 2009
    Location
    East Bay Area
    My Bikes
    '09 Trek 7.5 FX, '90 Trek Antelope 830, '07 Dahon Mariner
    Posts
    110
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by RacerOne View Post
    I've had three flats on my cyclocross bike in the past couple of weeks, all of them at the valve stem. At first I thought it was the cheap rim strip that came with the "Vuelta XRP Cross for Disc or Rim DoubleWall, black anodized" wheels allowing contact between the stem hole and the tube / stem junction. I replaced it with quality tape but low and behold I flatted in the same way yesterday.

    Basically it looks like they are getting cut right at the base where the stem joins the tube. I'm running about 35#'s in my 34mm tires with Kenda Q 27-32 tubes. When I put the tape on I checked for sharp edges but didn't notice anything out of the ordinary.. any suggestion?
    Is the cut on the thickened area next to the stem, or right next to the thickened area? I've noticed a big difference in the size of the thickened area between different brands of tube. Recently I replaced a REI/Kenda tube with a Michelin Airstop tube. The Michelin's thickened area was twice the size of the REI/Kenda's. The REI/Kenda tube failed right next to the thickened area, but I've had no issues with the Michelin tube. I didn't find any rim strip problems or rim burrs either.

  5. #5
    Hills hurt.. Couches kill RacerOne's Avatar
    Join Date
    Jun 2008
    Location
    Brazil, IN
    My Bikes
    1991 Specialized Sirrus Triple, 2010 Trek Madone 6.5 Project One, 2012 Cannondale Caad10, 2013 Trek Crockett
    Posts
    3,361
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Good suggestions guys, I'm going to recheck for burrs, double up the area with a spent tube cut-out and possibly change brands. the cut is about an 8th of an inch below the stem / rubber joint.

Posting Permissions

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