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  1. #1
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    Bolt sizing for use w/ only one chainring?

    Hello,

    When you look at chainring bolts at places like SRP etc., they list a BMX 10 piece Ti or Alum bolt set. I'm guessing it's "BMX" because there is only one chainring in the front, which probably makes the bolts a bit shorter, correct? I have a Rohloff hub and only use one outer ring.

    Do you guys think the shorter BMX bolts are what I need? I've ordered two sets from SRP, but I did not request the "BMX" bolts. I did measure the steel bolts I'm using now, and I thought they were 8mm - I think I may have been off a mm or so. Are the BMX bolts generally 7mm in length?

    Thanks,

    SDW

  2. #2
    All 26.5" all the time!
    Reputation: Zanetti's Avatar
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    It's the nuts that are generally shorter on BMX/track chainring bolt sets.

    If you end up with a bolt set for a double crankset, you can use 10mm x 3mm tall axle spacers (from Wheels Mfg.) behind the longer, 'double' length nut, to fasten a single ring.

  3. #3
    Loose Nut Behind d' Wheel
    Reputation: Lucky's Avatar
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    Quote Originally Posted by swalters
    Hello,

    When you look at chainring bolts at places like SRP etc., they list a BMX 10 piece Ti or Alum bolt set. I'm guessing it's "BMX" because there is only one chainring in the front, which probably makes the bolts a bit shorter, correct? I have a Rohloff hub and only use one outer ring.

    Do you guys think the shorter BMX bolts are what I need? I've ordered two sets from SRP, but I did not request the "BMX" bolts. I did measure the steel bolts I'm using now, and I thought they were 8mm - I think I may have been off a mm or so. Are the BMX bolts generally 7mm in length?

    Thanks,

    SDW
    I have two leftover BMX chainring bolts in the parts bin. One has 8mm threads and one has 6mm threads. Both have 5mm nuts. The remaining 4 of each are in service holding single middle rings to std mtb cranks. The one with 8mm threads will just reach a little further into the nut. For a single ring, BMX bolts are what you need unless you want to run spacers like the other poster mentioned.

    Four of those bolts are here:


    Kathy :^)
    Look where you want to go. This is as true in life as it is in mtbiking.

  4. #4
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    So there really is no standard sized..........

    Quote Originally Posted by Lucky
    I have two leftover BMX chainring bolts in the parts bin. One has 8mm threads and one has 6mm threads. Both have 5mm nuts. The remaining 4 of each are in service holding single middle rings to std mtb cranks. The one with 8mm threads will just reach a little further into the nut. For a single ring, BMX bolts are what you need unless you want to run spacers like the other poster mentioned.

    Four of those bolts are here:


    Kathy :^)

    BMX bolt, as you have a 6mm and an 8mm, correct? Bolts I ordered from SRP were 8mm, I believe, and they did not fit. I suppose I will order a set of either 6 or 7 mm - that should do it.

    Thanks,
    SDW

  5. #5
    All 26.5" all the time!
    Reputation: Zanetti's Avatar
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    Quote Originally Posted by Lucky
    I have two leftover BMX chainring bolts in the parts bin. One has 8mm threads and one has 6mm threads. Both have 5mm nuts. The remaining 4 of each are in service holding single middle rings to std mtb cranks. The one with 8mm threads will just reach a little further into the nut. For a single ring, BMX bolts are what you need unless you want to run spacers like the other poster mentioned.

    Four of those bolts are here:


    Kathy :^)
    That's one kick-ass cruiser you got there, Kathy.

  6. #6
    Want to vent?
    Reputation: The SS Boz's Avatar
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    6mm is single
    "I'm supa-fly TNT, I'm tha guns of the navarone!"

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