Track Cranks

Discussion in 'Cycling Equipment' started by davf1, Feb 24, 2008.

  1. davf1

    davf1 New Member

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    Hi
    I need to get a new set of track cranks to replace my SR. I have a particular requirement and maybe someone can help out.

    1/ Needs to be square taper and 144bcd.

    2/ I need to maximize the offset between pedal location and crank bolt location to allow clearance for my ankle.

    Can anyone make some suggestion especially with actual dimensions. ie the difference in Q-factor measured at the pedal thread compared to the equivalent dimension measured at the crank axle (outside-outside)

    I know that Miche Primato are one option with a crank offset of approx 4-5mm each side. Does anyone know what Campag is. Cannot find the information elsewhere

    many thanks
    Dave
     
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  2. alfeng

    alfeng Well-Known Member

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    If you need to increase the Q-factor, Harris Cyclery has what they call "kneesaver" pedal spacers which offsets the pedal from the crankarm ... maybe, by much too much for use on a Track bike:

    [​IMG]

    http://sheldonbrown.com/harris/pedals.html

    Which pedals are you currently using AND how much did you actually want to increase the Q-factor by?

    If it only a couple of millimeters, you can put a spacer/washer between the pedal & crank arm.
     
  3. shazzy

    shazzy New Member

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    Track cranks all tend to be very low Q, but the business cycles (US) tech page has some Q factor numbers for them.

    Also, pedals may be a way of widening the Q- keywins for example come with a few different axle lengths so as to give some adjustability.
    Good luck.
    S.
     
  4. davf1

    davf1 New Member

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    Thanks for all the feedback guys.

    I didn't actually want to increase the Q-factor as such, but reduce the clearance at the bottom bracket, if that makes sense. Anyway I have ordered a set of the Miche Primato which I hope will give me enough for what I want. Guess I will have to stop pedalling like a duck lol.
    Would be grateful if you could post a link to the US site you mentioned. Might be a useful source of info for other stuff.

    cheers
     
  5. shazzy

    shazzy New Member

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  6. alfeng

    alfeng Well-Known Member

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    If you just want(ed) a shorter spindle, I am pretty sure that you can mount your crank onto a 102mm Campagnolo Record/Chorus BB ... the taper hasn't changed from way-back-when till now. You probably have one, so you could do a "quick" test fit ...

    I'm not sure if those Campagnolo BBs have more (initial) resistance than you want -- you could "flush" the grease out & relube (tedious?), accordingly ... or, go to a bearing shop & hopeully get replacement (non-sealed) cartridges OR possibly some unsealed "caged" bearing cartridges with the right dimensions ... maybe, someone has ceramic bearings/cartridges that will fit.

    The double-cartridges on the drive side were poorly spec'd, IMO ... it would have been better if the cartridges were the same size as on the non-drive side where the actual size of the ball bearings inside the cartridges would not have been closer to Red Ryder BB-size than to the size that is typically found in a BB ... consequently, you CAN crack those bearings under heavy load & you should probably anticipate replacing them.

    If your frame has an Italian threaded shell, I think I would consider mounting the Campy 102mm BB in reversed position where the single cartridge is on the drive side and the two smaller ones are on the non-drive side ... OR, reverse it IF/(after) you need to replace the bearings due to an actual failure (sounds ominous, no doubt).

    If the 102mm spindle is what you want, you CAN probably get a cartridge bearing that will sleeve onto the drive side of the spindle whose outer diameter will nest in a NORMAL ("vintage") BB cup, so THAT inner diameter dimension of the cup can be the outer dimension of the bearing -- all of that may be more fiddling than you want to do. Anyway, in that vein, I've mounted Shimano BB cartridges into French BB cups & a set of old/proprietary Raliegh cups by using internal shims to "center" the cartridge.

    I had not given a lot of thought to reversing the internals of an English threaded 102mm Campagnolo BB, but, it could probably be done without too much effort if you use OTHER cups & are willing to fiddle with it.

    Of course, more importantly, I'm not sure if your crankarms will still clear your chainstays -- depending on your current BB spindle length, the arms will be 3-to-5mm closer to the stays -- I would think they would/should; but, you'll want to measure the existing gap to make sure you will have MORE THAN 1mm after mounting the cranks on a 102mm spindle.

    Of course, THE SHORTER SPINDLE WILL AFFECT THE CHAINLINE, so you'll have to weigh the dis-/advantages & may not want to use it.
     
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