Advertise on Bikeforums.net



User Tag List

Results 1 to 13 of 13
  1. #1
    Senior Member
    Join Date
    Dec 2005
    Posts
    687
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Spoke-induced flats

    Just posted re this in the Road Cycling forum (Wheel Woes (Reynolds Alta Race)--Help?, but this is probably a better place.
    Bottom line is my spokes on my Reynolds Alta Race wheels keep causing flats. I have rim tape on there. Is there anything I can do or are these wheels just not for me?

  2. #2
    Senior Member
    Join Date
    Sep 2001
    Location
    Montreal
    My Bikes
    Peugeot Hybrid, Minelli Hybrid
    Posts
    6,521
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Those are double wall rims, so the spokes should not be coming anywhere near the tube. I think you have been getting pinch flats caused by hitting bumps in the road with too low tire pressure. If you are running tires 23 or 25 mm wide, the pressure should be over 110 psi at the back and close to 100 psi at the front. If the rim tape wasnt fitted right, the punctures could have been caused by the tubes being forced against sharp edges on the holes at the base of the rim.

  3. #3
    Senior Member
    Join Date
    Feb 2005
    Location
    Oklahoma
    My Bikes
    Trek 5500, Colnago C-50
    Posts
    9,122
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    How do you know the spokes are causing the flats?
    How are they getting through the Velox? This doesn't seem credible.
    Are you sure the holes in the tubes are on the rim side?
    Are you indexing the tires so that you can align the holes in the tubes with the location of the tires?

    Running low pressure will not help and can cause more problems.

    Al
    Last edited by Al1943; 09-26-06 at 04:36 PM.

  4. #4
    Senior Member barba's Avatar
    Join Date
    Nov 2005
    Posts
    4,083
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It is not clear to me that it is a spoke problem. Have you felt around inside the tire and rim for any debris or burs stuck in the carcass of the tire or on the rim? Is the flat happening at the same place in the tube over and over?

  5. #5
    Senior Member Retro Grouch's Avatar
    Join Date
    Feb 2004
    Location
    St Peters, Missouri
    My Bikes
    Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
    Posts
    23,840
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Check your rim tape. It has to completely cover every single spoke hole. It the tiniest crescent of spoke hole is exposed, air pressure will force the inner tube into that space and eventually cut the tube. It's best if your rim tape is wide enough to completely span your rim from flange to flange but rims come in more width sizes than does rim tape.

  6. #6
    Senior Member
    Join Date
    Dec 2005
    Posts
    687
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    To answer all the questions:
    I felt around inside the tire; nothing. I just pulled the tire off in the comfort of my house and the tire's perfect. No puncure, no debris.
    The puctures occurred in different places in the tube, but each time on the inside, facing the rim. I just checked my last patch and it's right over a spoke hole.
    I had another flat after I put the Velox tape on, though I think it was because the tape was pushed to the side. Stupidly I bought the 1cm Velox as opposed to the 17mm. I had the original rim tape wrapped around the Velox, but they look like they were both pushed to the side. When I got my next flat (number 7), I put the second roll of Velox on the same rim, so I had 3 layers of tape--2 Velox and the original tape (which was the more elastic rubbery stuff). That's also when I decreased the tire pressure. After that, no flats.
    I'm pretty confident that inflating the tire to a high pressure contributed to this problem, since I flatted much more quickly when the tires were fully inflated, and once I dropped the pressure down way low I had no more flats.
    I also checked for burrs, and nothing significant, though I suppose there is a VERY slight burr around some of the holes. How should I smooth those out?
    Looking at the wheel again it does seem like it would be very odd for the spoke to be causing this problem. They are far from the tire.
    I don't think they were pinch flats since I've had those before and none of them had the tell-tale "snake bite" holes. They were all single hole flats. Plus, I had 7 of them, and there's n way I'd have 7 pinch flats in 60 or so miles.
    It was not happening inthe same place each time, which also puzzled me.
    This is pretty wierd. The most logical explanation is the holes in the rim were causing the problem, but I've never had this happen before.

  7. #7
    Senior Member
    Join Date
    Feb 2005
    Location
    Oklahoma
    My Bikes
    Trek 5500, Colnago C-50
    Posts
    9,122
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by NRRider
    The most logical explanation is the holes in the rim were causing the problem, but I've never had this happen before.
    This is actually very common. With high pressure tires the tube will extrude into the spoke hole and will fail.
    It's important to have the correct width Velox.

  8. #8
    Senior Member
    Join Date
    Sep 2001
    Location
    Montreal
    My Bikes
    Peugeot Hybrid, Minelli Hybrid
    Posts
    6,521
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I have had 3 flats on the 17 mile ride to work due to bad rim tape leaving holes partially exposed. You can remove sharp edges from the holes with a Dremel, or by running an oversize drill in them slowly by hand. Then use rim tape that covers the bottom of the rim from wall to wall.

  9. #9
    so much for physics humble_biker's Avatar
    Join Date
    Aug 2006
    Location
    over there
    My Bikes
    Scott CR1 team, Fuji track pro, NYCbike, Cannondale, Free Spirit, GT Edge
    Posts
    562
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Are there little "blow off" holes on the inside of the rim near where the vertical part meets the horizontal part? Often times if these little holes are present and depending on the quality of the tube they can be the fault. (Sorry for the weird description) If this is the case cover those holes with a wider tape or change to a heavier weight tube.

  10. #10
    Senior Member
    Join Date
    Dec 2005
    Posts
    687
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by humble_biker
    Are there little "blow off" holes on the inside of the rim near where the vertical part meets the horizontal part? Often times if these little holes are present and depending on the quality of the tube they can be the fault. (Sorry for the weird description) If this is the case cover those holes with a wider tape or change to a heavier weight tube.
    I'll have to check that when I get home. You mean right where the sidewall of the rim meets the part that the rim tape is applied to (sorry I don't know the correct names either)?

  11. #11
    Dog is my co-pilot 2manybikes's Avatar
    Join Date
    Jun 2003
    My Bikes
    2 many
    Posts
    13,745
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Al1943
    This is actually very common. With high pressure tires the tube will extrude into the spoke hole and will fail.
    It's important to have the correct width Velox.
    I have also had this happen with the stretchable plastic rim strips, the strip went right down into the hole enough that the tube was stretching down into the hole too much. Only at 130 psi. Not at 125.
    I fixed it with Velox.
    [SIGPIC][/SIGPIC]

  12. #12
    Senior Member
    Join Date
    Dec 2005
    Posts
    687
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by 2manybikes
    I have also had this happen with the stretchable plastic rim strips, the strip went right down into the hole enough that the tube was stretching down into the hole too much. Only at 130 psi. Not at 125.
    I fixed it with Velox.
    Very interesting. This may be what happened. The Road Morph pump that I use seems to inflate to a level higher than indicated on the guage, so it's possible that I was overinflating, though the first flat was on a wheel inflated using my home pump, which should be accurate. I still think it's something like this, or perhaps a combination of this and rough edges around the holes. Should stick with Ksyriums and I wouldn't have to deal with this nonsense.

  13. #13
    Senior Member
    Join Date
    Dec 2005
    Posts
    687
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Follow-up: Stopped at the LBS and picked up some 17mm Velox yesterday, installed it last night, filled the tires to 110 psi and rode 30 miles this morning. No problems. Hopefully that solved the problem. Thanks everyone for your help. Now if I could only eliminate that clicking in the BB. Time for a new thread....

Posting Permissions

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