where to find a replacement cranks arm?

jojdavies
jojdavies Posts: 3
edited January 2010 in Workshop
I have got the same problem - except that I can't find a new left crank arm anywhere (antique racing bike from 1985 - anyone seen a 172.5mm square ended left crank arm lying around / for sale?),,, did you really glue the bolt into the bottom bracket??

Comments

  • Ben6899
    Ben6899 Posts: 9,686
    I have some old gear in the garage - I'll have a look at the crank tomorrow and report back. For clarity, is crank length measured centre to centre (BB spindle to pedal spindle)? In case it isn't stamped on the part itself.

    Ben
    Ben

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  • Thanks. That's really kind. It's got the length stamped on it - it's a shimano 600
  • balthazar
    balthazar Posts: 1,565
    Generic left cranks should be sold at any LBS, about a tenner I think. They're likely to be 170 or 175, though, which you may have to live with. I managed to put a few thousand miles on a commuting bike once before I noticed the cranks were different lengths though — it doesn't matter much. BTW, yes, they are measured centre to centre.
  • maddog 2
    maddog 2 Posts: 8,114
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • Ben6899
    Ben6899 Posts: 9,686
    Jo,

    This is what I have in my garage - it came off the Peugeot which I stripped down before building into my winter bike. It's square taper, but unfortunately the crank length is 170mm and I'm not even sure what model it is, only that it's Shimano.

    Anyway here are a few photos of the whole, although I'm guessing it's not what you're after. The whole lot's available for the price of postage - the BB came out easily so there should be no damage to the threads.

    IMGP0987.jpg
    IMGP0988.jpg
    IMGP0990.jpg
    IMGP0991.jpg

    Ben
    Ben

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  • sheffsimon
    sheffsimon Posts: 1,282
    jojdavies wrote:
    I have got the same problem - except that I can't find a new left crank arm anywhere (antique racing bike from 1985 - anyone seen a 172.5mm square ended left crank arm lying around / for sale?),,, did you really glue the bolt into the bottom bracket??

    Bike shop??
  • Stellite
    Stellite Posts: 544
    Try the bike station in edinburgh, they are selling a shimano 600 chainset on ebay at the mo

    http://shop.ebay.co.uk/thebikestation/m ... ksid=p3686
  • andrew_s
    andrew_s Posts: 2,511
    jojdavies wrote:
    Thanks. That's really kind. It's got the length stamped on it - it's a shimano 600
    That's the model number (old Ultegra), not the length.

    As stated, finding 172.5 rather than 170 or 175 will be difficult. However, it may be that you won't really notice odd cranks after a bit.

    Another point is that square taper cranks come in two orientations: with the diagonal parallel to the crank "diamond", and with the sides of the square parallel to the crank "square".
    If you get it wrong the cranks will be at 135deg rather than opposite each other.
    Shimano seem to be diamond, but TA Zephyr are diamond and TA Carmina are square, so you can't necessarily just rely on the brand name when buying..
  • balthazar
    balthazar Posts: 1,565
    andrew_s wrote:
    Another point is that square taper cranks come in two orientations: with the diagonal parallel to the crank "diamond", and with the sides of the square parallel to the crank "square".
    If you get it wrong the cranks will be at 135deg rather than opposite each other.
    That's a very good point, I'd completely forgotten that this can vary. Take heed OP!