Advertise on Bikeforums.net



User Tag List

Results 1 to 11 of 11
  1. #1
    Member
    Join Date
    Nov 2009
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Crank Clearance when bolts are torqued- single speed bike, help appreciated

    my friend bought Sugino grand mightys for his urban outfitters singlespeed bike (dont ask me why -_-)
    he asked me to install it because i have the tools.

    i have a slight problem that could get bigger.
    i installed the bottom bracket, i seated the cranks and torqued in the bolts to +/- 25 ft lbs

    i rode it around a bit to test it out my work....not so good, the drive side arm was kissing the stay everytime it went up.

    i sat down with the bike, cried a bit, then started over.

    i double checked the bottom bracket, reinstalled it. reseated the cranks but this time i didnt push the drive crank all the way in with the wrench (so the drive side is not torque +/- 25 ft lbs). and WAH LAH, the crank clears the chainstay.

    my question is: Is there anyway for me to torque the crank around 25 ftlbs without pushing it all through the spindle? i need about 1mm or 1.5mm of space for the crank to clear the stay.

    thank you for reading, and any help/comments appreciated.

  2. #2
    17yrold in 64yrold body
    Join Date
    May 2010
    Location
    Northern CA
    Posts
    922
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You should be able to find that size shims for BB's at loosescrews.com or bikeparts.com. Just make sure you have sufficient clearance for the 'shift' on the left crank arm.

  3. #3
    Member
    Join Date
    Nov 2009
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    what would the shims do for the BB?


    ahh nevermind, now i get it. hmm okay thanks, spacers should help
    Last edited by sagbuya; 08-04-10 at 10:45 PM. Reason: NOW I GET IT

  4. #4
    Member
    Join Date
    Nov 2009
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by badamsjr View Post
    Just make sure you have sufficient clearance for the 'shift' on the left crank arm.
    AHH i just checked, the left crank might not clear, any other suggestions?

  5. #5
    Senior Member
    Join Date
    Nov 2008
    Location
    Bay Area, Calif.
    Posts
    4,824
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Yes, there are a few approaches to take. A spacer under the fixed cup of the BB is one - that'll move the cranks over a little to the right, so be sure you have enough clearance on the left side crank before doing this. A longer spindle would be a second method but requires that you're able to find one of the right length.

    Our tandem had a similar problem, but it was on the left side and the crank rubbed on the lockring for the adjustable cup. Eager to get the bike up and running without having to wait for yet another part, I cut a shim out of a soda can and put it around the square taper of the spindle on the NDS. Tightened everything down and that gave sufficient clearance. Admittedly it's not the preferred solution, but it has held up fine for over 30 years and quite a few repackings of the BB bearings. Of course when/if the spindle ever wears out I'll try to replace it with one that's longer on the left side (which isn't completely NDS since the captain's drive power is on that side).

  6. #6
    Member
    Join Date
    Nov 2009
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    the problem for is that i can't find a longer spindle for him, for cup and cone BBS

  7. #7
    Senior Member
    Join Date
    Nov 2008
    Location
    Bay Area, Calif.
    Posts
    4,824
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by sagbuya View Post
    the problem for is that i can't find a longer spindle for him, for cup and cone BBS
    Which was my problem as well. That's why I cut up the Coke can to make a shim that I wrapped most of the way around the square taper of the BB spindle before sliding on the crank.

  8. #8
    Member
    Join Date
    Nov 2009
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    i want to try it, but my can cutting skills are lacking.

  9. #9
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    25,596
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    If you can't find a longer spindle for the current cup-and-cone bb, consider a Shimano cartridge. The UN-5X series is available in spindles of 122.5 and 127.5 mm.

    I had an older Trek MTB that had the same problem and it took the 127.5 mm bb to let both crank arms clear the chainstays.

  10. #10
    DRF aka Thrifty Bill wrk101's Avatar
    Join Date
    Jan 2008
    Location
    The NC Mountains
    My Bikes
    Too many to list, all vintage
    Posts
    19,461
    Mentioned
    57 Post(s)
    Tagged
    1 Thread(s)
    +1 Just buy a new cartridge bb. The Shimano UN26 series (that's their bottom line) can be found on line for $10, in many different spindle lengths.

  11. #11
    Old fart JohnDThompson's Avatar
    Join Date
    Nov 2004
    Location
    Appleton WI
    My Bikes
    Several, mostly not name brands.
    Posts
    12,643
    Mentioned
    9 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by sagbuya View Post
    AHH i just checked, the left crank might not clear, any other suggestions?
    A longer axle?

    How wide is the bottom bracket shell? Are you perhaps installing a bottom bracket intended for a 68mm shell into a 70mm shell?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •