what taper are TA chainsets?

maddog 2
maddog 2 Posts: 8,114
edited November 2007 in Workshop
ISO or JIS

:D
Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer

Comments

  • maddog 2
    maddog 2 Posts: 8,114
    found my answer

    ISO

    http://www.sheldonbrown.com/bbtaper.html
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • scherrit
    scherrit Posts: 360
    Yup,
    most euro are ISO... I'm mostly worried about track specs and use the business cycles site for the low-down:
    http://www.businesscycles.com/tr-refspec.htm
    If you're as fat as me, all bikes are bendy.
  • satanas
    satanas Posts: 1,303
    I'm not convinced that Sheldon has the whole story right...

    In my experience:

    1. Older TA cranks (ie Cyclotourist) had a larger-than-ISO taper
    2. Fitting an ISO crank on a same length JIS spindle moves the crank out much less than 4.5mm; IME I'd say 1-1.5mm is closer to reality
    3. Avocet (made by Ofmega) cranks work fine on ISO taper spindles; the trick is finding one with the right length. This could be a problem as axle length was similar to Campag/SR Royal/Sugino Mighty of the same era - i.e. asymmetrical

    As Sheldon says, it is possible to mix ISO and JIS but there are things to watch out for and they are hard to describe without pictures. You are more likely to have major problems fitting JIS cranks on ISO spindles as these can bottom out on either the end of the spindle or the bottom of the flats; if this happens the cranks can be damaged.
  • maddog 2
    maddog 2 Posts: 8,114
    I must admit I also thought the 4.5mm value was dodgy.

    I fitted a TA Vega to a mates bike and used a UN73. You could tell the crank was a bit too far out but it was perfectly useable.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer

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