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double to triple

Old 09-10-08, 10:08 AM
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saibiker
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double to triple

Just bought a 1983 Trek road bike, mint cond (630 I think, based on the vintage Trek site) ) wanting to change from double to triple for climbing. Will this work?

Current:
Crank: SR40/52
FD: SR blueline
BB: square tapered
RD: Short cage SR

What I'm thinking of buying is Sugino xd600 crank. Will this work? Will there be a chainline issue that I'll need to deal with? Other?
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Old 09-10-08, 10:39 AM
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sch
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Likely will need a triple length BB, usually about 118mm long.
BB shell length is likely to be 70mm, easy to measure this.
So you would want a square taper BB axle 70x118mm size.
RD would be best changed to a long cage for chain wrap
reasons. FD might work as is. Shifters? If downtube,
should handle the triple ok. You want take offs? I might
have some.
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Old 09-10-08, 10:59 AM
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saibiker
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BB length is 68.

Current setup is downtube shifters, which I'm changing to barcons. Found a pair of older Suntour on CL.

What do you mean by "take offs"?

Jon
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Old 09-10-08, 11:03 AM
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Al1943
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sch has given you some very good information. The BB length is not 68, but it may be the BB shell diameter.
If you count the teeth on the inside chainring you may find that it is a 39 instead of a 40.
Good luck with your project.

Al
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Old 09-10-08, 02:27 PM
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sch
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LBS do a lot of takeoffs, ie removal of stock stuff to 'upgrade' to better.
I vaguely recalled taking off my squaredrive triple about 10yrs ago and
changing to a octalink 9spd. Since my first post I checked and have
a 68x118 square drive Shimano BB and 105 level cranks for triple also
sq drive. No crank CW screws or apparently any CW. Yours for dirt.
Maybe 2kmi on the BB. Can check on CW, maybe another box.
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Old 09-10-08, 02:37 PM
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AlamoCoach
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Originally Posted by sch View Post
Likely will need a triple length BB, usually about 118mm long.
BB shell length is likely to be 70mm, easy to measure this.
So you would want a square taper BB axle 70x118mm size.
RD would be best changed to a long cage for chain wrap
reasons. FD might work as is. Shifters? If downtube,
should handle the triple ok. You want take offs? I might
have some.
For the Sugino XD600 he is considering, Sugino recommends a 113mm square taper bottombracket for 135mm rear wheel mountain frames and 107-110mm for 130mm rear road frames
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Old 09-10-08, 02:51 PM
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saibiker
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Sch...Thanks for checking. I'm definitley interested. What are CW's?
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