sprocket against spokes myth

Discussion in 'Motorized Bicycle General Discussion' started by camlifter, Jun 14, 2010.

  1. camlifter

    camlifter Active Member

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    i built a cranebrook about a year ago, to get the chain to line up i bolted the sprocket right up against the spokes only using one rag joint on the back side. yesterday i took it apart to up grade to a 12 gauge spoke wheel and 36 tooth sprocket, guess what. the spokes showed no wear at all from being against the sprocket, thats with the 14 gauge huffy wheel and a lot of hard riding. so i think we can put the myth to rest that doing so will ruin your wheel.
     
  2. NunyaBidness

    NunyaBidness Active Member

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    It is NOT a myth, you just got real lucky. Putting the metal sprocket against the metal spoke DOES cause the sprocket to chew the spokes. If you want I can send you some spokes that will show you what happens.
    Again, it is NOT a myth, you just got really lucky.
     
  3. camlifter

    camlifter Active Member

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    i wouldn't say it was luck, mine showed no wear at all, and this bike has lots of hard miles on it. if your sprocket is loose it would rock back and forth and cause wear, but if it's tight you won't have a problem.
     
  4. charles.paskell

    charles.paskell New Member

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    I have to agree with camlifter on this one I too only use one rag joint and as long as your sprocket is tight and true against the spokes than you will be okay.
    Grubee Power!
     
  5. WayneC

    WayneC New Member

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    Guess I got "lucky" too. Before I changed to the HD freewheel I too went a year with the above
    setup. No wear; no tear.
     
  6. 2door

    2door Moderator
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    This is another case of the gospel, as we know it, not being quite so absolute. As with most methods, ideas and avenues there is, as they say, "more than one way to skin a cat".
    What works for some will not be so successful for another. We could site examples of these things all day and there would always be opposing opinions based on what works for some and what doesn't. Camlifer is right about the tighness and alignment of his sprocket. If the sprocket is tight and doesn't move then there is no wear. Its the friction of movement that will damage the spokes, not just the fact that there is metal to metal contact. Take a look at any machine and you'll see metal bolted to metal. Its only when things get loose that the wear begins. The only issue I see that might be a problem would be the distortion of the spokes from being bolted to a flat surface when they have a natural slant inward. I've not run into an alignment problem that required moving the sprocket outward that far but if I ever do I might consider mounting it without the rubber, but you can be sure that I'd keep a close eye on that potentially trouble prone area. Just my thoughts
    Tom
     
  7. Mac

    Mac New Member

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    I initially ran mine without the rag joint on the outside but I put a buttload of CA thick glue on the spoke/sprocket contact point and gave it a good shot of accelerator (it was clamped up and true already) just to prevent the fretting/galling. When I changed sprockets, the spokes were worn a bit(stock schwinn rim), I guess it could go either way. I'd hate to loose a rim at speed, even 25mph hurts allot.

    Mac
     
  8. nidyanazo

    nidyanazo New Member

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    Even if it's tight there will still be bending if you ride hard. 'popping' the clutch does damage. But you gotta wring those HT motors out if you want to move 'quick'
    Re*lace with 12ga spokes....
     
  9. Cabinfever1977

    Cabinfever1977 New Member

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    Mine shown no wear either, i mounted mine without the outside rubber cause it would have spaced out my sprocket too far, but i did use a very thin metal spacer to keep the chain from touching the spokes. I don't reccomend anyone do it,but that is how i chose to mount it.
     
  10. Dave31

    Dave31 Moderator
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    I have seen two customers bikes that did not use the rubber and I did see wear and one had several broken spokes from being worn down from the sprocket. If your sprocket does not have any movement, then yes you probably can get away without any wear. But too often many don't even bother to check anything after assembly.
     
  11. bulletholes

    bulletholes New Member

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    I have made over 15 builds and use a set of rag joint backing plates to space out the sprocket and use one rubber on the backside and tighten securely. I have never experienced a problem, as long as the sprocket is tight, with metal to metal wear.
    I always check fasteners for tightness.
     
  12. KCvale

    KCvale Active Member

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    My first build, like many others here, was a Huffy Cranbrook.
    And like them I had sprocket alignment and dust cover issues using both rags.

    I flipped the sprocket so the cup faced out and up against the 'tits' on the spoke heads coming through the rim and just used the back rag.

    [​IMG]

    Before I tightened it down I rotated the sprocket in the direction of drive force so the bolts were up against the spokes as well (no forward slip).

    [​IMG]

    The sprocket fits the hub perfect so no "wobble", no brake arm issues, and as mentioned no dust cap issue either.

    [​IMG]

    The guy in 'finical bind' I sold it to came buy several months later when the end cap of his tailpipe blew off and I checked it when I did chain matching on it (this was my first build, before I learned to scorn drive chain tensioners) and it looked great sprocket to spoke wise.

    I gave the mounts a re-torque because they were due but to date still no problems with the mount and he is on his 3rd set of tires from sheer mileage wear.

    i DO NOT recommend the Cranbrook bike though.

    Crap bike, hard to build, and it essentially has no brakes.
    I put a side pull front brake and larger rear pedal sprocket on, but by the time you add up the parts cost and time you could get a bike that has what you need anyway and goes together easier.
     

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