External BB to square taper - possible?
Does anyone know if a bottom bracket / bearing kit exists for converting an bike that has external bearing cups (Shimano 6600 series) to an older square taper design bottom bracket?
I know this is a "backwards" conversion but I've got a old Specialized Allez frame with a square taper BB that I'm running as a single speed. It was my first bike and the shop I got it at sized me incorrectly (it's a 50 cm and I should be a 52 or 54). I also have a Trek Madone 5.2 frame (unfortunately just hanging on the wall) that is the correct size. Wondering if there is any way I can move my current crank over with a BB conversion kit rather than having to buy a crank and bearings. Thanks in advance. |
Originally Posted by Mojo GoGo
(Post 12691643)
Does anyone know if a bottom bracket / bearing kit exists for converting an bike that has external bearing cups (Shimano 6600 series) to an older square taper design bottom bracket?
I know this is a "backwards" conversion but I've got a old Specialized Allez frame with a square taper BB that I'm running as a single speed. It was my first bike and the shop I got it at sized me incorrectly (it's a 50 cm and I should be a 52 or 54). I also have a Trek Madone 5.2 frame (unfortunately just hanging on the wall) that is the correct size. Wondering if there is any way I can move my current crank over with a BB conversion kit rather than having to buy a crank and bearings. Thanks in advance. You can't use the external bearings, however. Different system, diameters and spindle length. |
Strip the frame and start over, as said above.
Unscrew the external bearings, they were machined to screw into BB's as they were made, right is LH thread. you Will need special tool to grip the external bearing cup, to unscrew them, so if there is no desire to buy that tool, to use once, get the bike shop to use theirs. the frame threading is unchanged, so you then install a square taper BB . package the external bearings with the crankset they came with. only a BB 30 set is needing a unique frame. |
Originally Posted by cyccommute
(Post 12691687)
You just need the proper bottom bracket for the square taper. The external bearings thread into the bottom bracket shell of the bike with the same thread pitch and direction as a cassette bearing.
You can't use the external bearings, however. Different system, diameters and spindle length. (just assumed some sort of backward incompatibility (e.g., external cups having external bottom bracket threading) had been designed in by the manufacturer) |
Originally Posted by Mojo GoGo
(Post 12691785)
So if I understand you correctly (I haven't looked at Madone frame in a year), the external bearing cups thread into the inside of the bottom bracket. So the square taper bottom bracket I'm currently running just needs to be removed from my Allez and should screw into the Madone frame no problem.
(just assumed some sort of backward incompatibility (e.g., external cups having external bottom bracket threading) had been designed in by the manufacturer) |
Originally Posted by Mojo GoGo
(Post 12691785)
So if I understand you correctly (I haven't looked at Madone frame in a year), the external bearing cups thread into the inside of the bottom bracket. So the square taper bottom bracket I'm currently running just needs to be removed from my Allez and should screw into the Madone frame no problem.
(just assumed some sort of backward incompatibility (e.g., external cups having external bottom bracket threading) had been designed in by the manufacturer) |
All times are GMT -6. The time now is 11:57 PM. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.