Newbie ? - Bottom Bracket size

Steven said:

I am updating the BB on my Giant tcr aero from a square taper to an
octalink (to fit my new crankset). I am not sure what size bottom
bracket to buy. One dimension is 109.5mm that is specific for the crank
but the other dimension I am unsure of.

It's 68 mm.

Quoted message said:

Any suggestions?

http://sheldonbrown.com/bbsize explains all about this, but 68 is all
you really need to know. All asian road bikes have 68 mm bbs.

Sheldon "Easy One" Brown
Santa Cruz, California
+--------------------------------------------+
| If it can't be expressed in figures, |
| it is not science; it is opinion. |
| --Robert A. Heinlein |
+--------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Steven said:

I am updating the BB on my Giant tcr aero from a square taper to an
octalink (to fit my new crankset). I am not sure what size bottom
bracket to buy. One dimension is 109.5mm that is specific for the crank
but the other dimension I am unsure of. Any suggestions?

Spindle matches crank, cups match frame.

Then some wag got the idea of making some BB shells wider so
now you also need to know of the bike is normal (68 for BSC,
70 for ITA) or wide ( 73mm)

In your case BSC and 68mm.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971