Non-puncture related flats

Discussion in 'Cycling Equipment' started by Resistorlead, Jul 12, 2010.

  1. Resistorlead

    Resistorlead New Member

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    Just curious- how many people have had flats due to what I consider wheel defects? That would be sharp edges or burrs in places that aren't completely covered up by the rim strip. There's the classic too-long spoke, but that's obvious on casual inspection. I just spent an hour with a Mototool and Craytex rubber abrasive wheel, polishing the edges where the drilling was a bit off center from the rim strip depression, giving access to a sharp edge or burr. Also, do you talc tubes or install clean?
     
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  2. Mojo Johnson

    Mojo Johnson New Member

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    I have been the victim of many of these types of flats. I didn't know what I was doing wrong until closely inspecting the rim tape. The tape I had was old and not quite wide enough to cover all the the sharp bits in there.

    I purchased some wider rim tape that completely covered all of the spoke holes and actually turns up slightly on the edges of the rim. Since applying this rim tape I have experienced zero internal punctures. No talc applied, just "proper" tape job.
     
  3. Sid Nitzerglobi

    Sid Nitzerglobi New Member

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    I had one these recently but I'm not sure exactly where I place the blame. Got a cut along the base of the valve stem while disengaging the pump. Not really sure if this was due to sharp edge of stem hole in the rim, defective stem joint on the tube, over tightening of stem nut (it was one of those fully threaded dealies), or other user error.

    Replacement tube is a non-threaded Giant model w/ a metal sleeve going a few mm below the rim so hopefully I won't have the same thing happen again any time soon.
     
  4. OldGoat

    OldGoat New Member

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    I've had one flat due to thin, worn-through nylon rim tape. On inspection, there were lots of little oval-shaped marks all round the inside of the tube--one for each spoke hole. Replaced w/ Velox. No problems since.

    I talc a new tube if replacing in my shop. I think it helps the tube "set" properly in the tire upon inflation. Tube will eventually adhere to the inside of the tire, but that's OK w/ me. Tube & tire pull apart easily when swapping tubes out on the road.
     
  5. alienator

    alienator Well-Known Member

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    I don't get any like that. If you apply rim tape properly, then even off-center spoke holes will be covered up. Inspecting a new rim before use is always a good idea. I don't talc tubes. Never have. I don't see why I would want to.
     
  6. swampy1970

    swampy1970 Well-Known Member

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    Just like putting on a pair of pants that are way too small, putting on narrow rim tape onto a wide rim is just plain silly and possibly dangerous...

    Spoke holes still showing after applying said tape? Check the packet and make sure you didn't apply a roll of rim thong.
     
  7. dhk2

    dhk2 Active Member

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    Talc coating for tubes is an old-school standard, maybe from the time that tubes were made from rubber and could stick together or stick to the inside of the tire. The butyl tubes I use (Conti) aren't coated when new anymore and don't seem sticky so I figure they don't need talc.

    My buddy still believes in it though. Before putting a spare tube in his seatpack, he carefully applies talc to the entire surface, then rerolls it and packs it in a ziplock bag (to keep the talc from getting all over). OTOH, I just pull the new tube out of the box and put it in my seatbag. I've carried "clean" spare tubes for years without having any problems.
     
  8. Resistorlead

    Resistorlead New Member

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    Needless to say, the rim strip (Velox) is the correct width for the wheel. The wheel is a narrow 27" from 1984, similar to a Mavic A119 in cross section. Not sure who made it, but I've had several just like it before, and with exactly the same problem. The problem is that the nipple access holes should, ideally, be centered in the trough where the rim strip goes. The spoke holes and reinforcements should, however, be offset slightly. In reality, the access holes tend not to be perfectly centered. When this happens, there's a cut into the wall of the rim strip trough and typically a sharp edge. OK, I should have taken a picture. The only cure, other than new wheels, would be a rim strip that was very wide and went up the side of the trough (not at all how it was designed to be), or smoothing the edges so that no tube damage can occur in those tiny circular areas the rim strip can't cover. I went with smoothing the edges. We'll see how reliable the wheel is now.

    I typically talc, but not religiously. Depends on how close the bottle is.
     
  9. cyberlegend1994

    cyberlegend1994 Moderator

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    None from the wheel itself, but I've had a few stem flats caused by receding rim tape, exposing sharp edges of the stem hole. A quick Dremel tool job to remove the sharp edges and a touch-up with cloth rim tape did the trick, haven't had a stem flat since.
     
  10. alienator

    alienator Well-Known Member

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    One thing to consider if you've got a rim with spoke holes that can't seem to be covered with rim tape or summat: use glass fiber packing tape to cover said holes. That said, any decent rim is going to have spoke holes drilled properly. Even the rear rims with offset spoke holes I've had were easily taken care of with Velox and no need for special prep.
     
  11. Resistorlead

    Resistorlead New Member

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    I've never been able to afford parts with no flaws so,

    "May your parts always give pleasure and never fall off!"
     
  12. widgetr

    widgetr New Member

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    because my hands go numb with carpel tunnel and my neck bends too much on a down bar road bike I am thinking about buying a Marin Mill valley bike....but wondering if I could ride a road bike with a stem extension to make me sit up higher..........so confusing...I need low gears...
    here is the link for the marin....hope to hear from someone with help...should I look at a road bike..then if it does not work out change to flatbar...........hope to hear
     
    http://www.bikepedia.com/QuickBike/BikeSpecs.aspx?Year=2010&Brand=Marin&Model=Mill+Valley&Type=bike
     
  13. Steve_A

    Steve_A Member

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    I'm going to sound like an ad here, but please do some reading on the Rivendell Cycles website. I'm not saying buy one of their bikes (although I'd love to) but there's a lot of information, some of it counter to the common wisdom of modern cycling. You may get some ideas and changed concepts. Velo Orange has similar bikes and equipment, some of it at lower prices than Rivendell.
     
  14. davereo

    davereo Well-Known Member

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    You should go to your LBS and speak to them about your specific issues. You should also try out any and all bikes you are interested in and make your final selection based on comfort and performance. A properly fitted bike is the best bike to own. The only way to find out what it is is to go out and ride it. Why go out and buy a bike that you may have to rework to suit your needs when you can ride away on one from the LBS.
     
  15. JM01

    JM01 New Member

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    You need to find a bike that fits. Your hands go numb and tingle because you're pressing on the nerve at the base of your palm...too much weight on hands that are not placed correctly. Your neck problems results on a top tube that's too long or a seat post that's too high. You need to ensure the correct position over the crank, not just the seat tube length but you may need to get a saddle with longer rails and move it forward.
     
    A riser stem and bar may help, but speak with someone who knows how to fit a bike when you're ready to buy again...1" on a bike is huge.
     
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