Tubes rim damage coming from nipple?

Discussion in 'Bicycle Repair' started by sabala, Mar 30, 2009.

  1. sabala

    sabala Guest

    Hi all,

    Had a flat Saturday from a metal wire thingy. Puncture proof Slime tube didn't work and Slime was all over back of down tube, front derailleur, back of shirt, outside of tube and inside of tire. Put in my spare tube and made it home ok.

    Sunday coming home about 7:15pm my new (non Slime) tube popped, upon inspection there was about an inch long slit in tube and also slimey from all the Slime that was inside the tire. I was carrying an older patched spare tube and put that in, took off and 1 mile the tire again went flat! I gave up and walked/carried my bike the rest of the way home along the beach bike path...finally made it home at 11:15pm.

    So that's the set up in case anyone needs that info.

    Ok, so today I'm changing the tube at home and cleaning up the Slime and sand/dirt all over the wheel rim. I notice the nipples close to the cassette side of the rim are damaged and the side of the rim each nipple has been scraped against. The nipples and rim on the opposite side are undamaged. I'm wondering what may be causing this?

    How bad is it that this is happening? Is it safe to ride on? Should I get the damaged nipples replaced ASAP? I couldn't find anything on the web yet so I'm unsure of what to do about it.

    I was running 2.1 Continental Town & Country with Slime puncture proof tubes at 60 psi. I was using a pretty thin rim liner with a layer of duct tape over that but I'm thinking of slicing an old tube to use as a rim liner instead.

    For the last week I'd been taking care of a friend's pets so I was doing about 16 miles a day riding. No problems at all until after that 1st flat on Sunday, then today saw the rim and nipples and was wondering if that had anything to do with it. I tried to take pics, sorry, not the greatest. You can't really see the nipple damage but I think you can see where they rub against the rim.

    Any thoughts??
     

    Attached Files:


  2. TINKERER

    TINKERER Member

    I've seen alot of strange things happen to a bicycle, but never anything like that. I am also scratching my head on this one.
     
  3. fetor56

    fetor56 Guest

    From your pics i can only speculate that the damage seems to be caused by the nipples from the drive spokes only....the non-drive spoke nipples don't appear to have contacted the rim.Possibly it's due to flexing of the spokes caused by incorrect spoke tension,or maybe even the spokes are too thin for your setup & can't handle the power.
    Whatever reason i'de get the toughest rim/spoke combination i could afford...make it a dual-walled rim so the spoke nipples are recessed into the rim & can't do damage.
    There are glues for spoke nipples but i've never tried them & besided think their unnecessary.
    You have the right idea with the thorn resistant tubes/tyre liners/slime,it's just a question of better hardware.........THINK TOUGH. :thinking:

    PS...if u havn't already done so cable-tie your spokes.
     
    Last edited by a moderator: Mar 30, 2009
  4. bamabikeguy

    bamabikeguy Active Member

    This is conjecture, but part of the principle of zip-tie-ing all the spoke intersections it that the spokes are moving in unison, right and left are sharing the stress.

    I've never seen scratches like that, but some sort of deep, potato-sized hole in the road could have pushed the nipples up on one side.

    That is why I wrap 4 layers of electric tape over the rubber gasket. Even then, when I look at it after a thousand miles, (say rotating tires front to back), a few of the nipples have nearly rubbed through that tape.
     
  5. bamabikeguy

    bamabikeguy Active Member

    As a P.S., I'm thinking there may be a quality difference between those slime puncture-proofs and the non-slime Pyramid brand I get from the bike shop, nearly the same price.

    I think I'm going to stick with Pyramids only this year, see if I can report on the quality control issue.
     
  6. arceeguy

    arceeguy Active Member

    The title caught my eye - didn't know what it had to do with bicycles until I read it.

    Remember - nipples up!
     
  7. meatwad

    meatwad Member

    .

    What I think what you are seeing is a rim built offset on the hub. What is sometimes necessary to do is to grind off the spoke heads where they extend past the nipple and into the tube area. The marks are from a grinder tool bumping the side.

    If not and it is due to rubbing something dangerous is going on.
     
  8. fetor56

    fetor56 Guest

    For sure,nipples up & don't have them rubbing on anything abrasive.
    Reminds me of Taters thread "how do i mount speedo?".....read through it and you'll see what i mean. ;)
    http://www.motoredbikes.com/showthread.php?t=10156&highlight=mount+speedo
     
  9. meatwad

    meatwad Member

    I should add that if it is due to rubbing..

    And i'm assuming that grey colored thing is what the belt goes onto..

    that there is too much torque being put onto that side of the wheel and that this side is wrapping up a bit. Should make the bike feel quite squirrely.

    Also believe or not 60 psi is enough to release a lot of tention off the spokes. That being said the wheel would still need to be tightened up from what it is now.
     
  10. sabala

    sabala Guest

    Well, the wheel is the "Eagle/Velocity 26" Rear Wheel w/105g spokes" I ordered along with my GEBE kit so it should be pretty bulletproof shouldn't it? I didn't think I'd need to put zip ties on but will do so in the future I guess! I'll also beef up the rim liner too.

    I weigh 165 lbs and I always pedal up to 10 -12 mph before engaging the throttle. I like pedaling a bit as I ride too. I have 315 miles on my bike and maybe 100 or so is pedaling without using the engine at all.

    While the last 4 months I've finally been learning bike maintenance, I haven't even touched on wheel building so my knowledge there is zero. I kinda understand truing but not 100% yet. Maybe I can take it into the bike co op I've been going to and see what they say.

    I wonder if anyone else out thar who ordered that wheel has the same thing happening? I never would've looked if slime didn't get everywhere.

    I feel sorry for my poor nipples.
     
    Last edited by a moderator: Mar 31, 2009
  11. fetor56

    fetor56 Guest

    I would have thought a custom GEBE wheel would be more than adequate for the job.....i also would have thought being such a custom wheel it would have been dual-walled.
    Dunno in reality how thick/strong these 105g spokes are,they look fine.Keep in mind your essentially driving your wheel through one side of the spokes.
    PM "the wheelmaster" & ask his advice,or email him on his website.If anyone knows he does,& please post results.
    http://www.thewheelmaster.com/
     
  12. Grinder scuffs

    (Quote from Meatwad) "What I think what you are seeing is a rim built offset on the hub. What is sometimes necessary to do is to grind off the spoke heads where they extend past the nipple and into the tube area. The marks are from a grinder tool bumping the side.

    If not and it is due to rubbing something dangerous is going on."


    Meatwad, your name doesn't give you enough credit ! your exactly right, you see, the wheel being offset toward the cassette, the spokes protrude through the nipple and into the tube unless their ground off flush, only the spokes on the cassette side stick through in this case because nearly all the tension is on that side of the wheel, the marks you see are from the grinder slipping off the top of the nipple while grinding, this has to be done otherwise the spokes that stick through would pop the tube instantly, it's very difficult to perform this task without having a few nicks on the rim.
    1, The rim has not been harmed and is still every bit as strong as before.
    2, Electricians tape makes a great rim band and keeps dirt out, combining tape And a rim band would be a great way to go.
    3, Make sure the spokes aren't sticking out anywhere past the nipples, if they are, grind them off better and smoother without going to far and taking to much nipple with it, (Bad things can happen if your not careful).
    4, The wheel looks sturdy, but you know who to contact if you continue to have trouble.. :wink:
    5, Double wall rims eliminate the bumps from the nipple and are less prone to flats, but a good tape job and liner should cure your problem....

    Best of Luck ! ! ! ! ! !
     
  13. arceeguy

    arceeguy Active Member

  14. sabala

    sabala Guest

    Thanks, that makes a lot more sense than the damage being caused from riding. I cut an inner tube for a liner, put the old liner on too and a layer of tape over that.

    I noticed my Conti T&C tire also had an inch and a half long slit going right through the tread and recessed area of the tire. Must've gone over somethin' fierce for that 2nd flat! So, not the nipps causing the flat after all.

    Had a couple mtb tires lying around and threw one on this morning. Just got back from a 16 mile ride and everything's ok!

    Thanks Wheelmaster and everyone else!
     
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