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BB sizing Q - mid 80's Trek(6 posts)

BB sizing Q - mid 80's TrekSenorPedro
Oct 22, 2003 7:35 PM
Hello all,

I have a mid 80's Trek road bike that I bought used and have done a healthy amount of upgrading to for use as my rain bike. Having put quite a few miles on this bike in the past years the B.B. decided to implode today. It feels like there is a bunch of gravel spinning around while I pedal and the spindle appears to be loose (small amount of play when grasping the pedals and rocking them)in the shell.

Definitely time for a new one, plus I have been running this older bb with Tiagra cranks and the left side taper doesn't allow for the crankarm to come inboard as far as it should, creating a screwed-up Q factor.

I am just wondering what length spindle I should get, I am fairly sure it is a 63mm shell. If it helps at all, the bike originally had Shimano Exage Sport cranks and is/was running a Tiagra double.

Thanks in advance,

re: BB sizing Q - mid 80's Trekrussw19
Oct 22, 2003 7:48 PM
Pedro, it's most likely a 68mm shell (think you had a typo) but it's easy to tell. Measure it... if it is about or less than 70mm, it's definately a 68. If it's longer it's a 73mm. Trek never made an Italian BB so it can not be 70mm. So above is 73, below is 68.

As for the spindle length, you need a 113mm spindle.

Oct 22, 2003 9:12 PM
Err, yeah I meant 68mm shell. Helps a lot,

re: 113?Rusty Coggs
Oct 23, 2003 4:45 AM
A tiagra triple uses a 113,the double uses a 110.
re: 113?russw19
Oct 23, 2003 10:17 AM
Got the info from Sheldon and the Harris Cyclery site. It seems that Sheldon may be wrong b/c the Shimano Europe site lists as you say... 110 double.

Thanks for the correction... you want to email Sheldon and tell him he's wrong? ;-)

re: SheldonRusty Coggs
Oct 23, 2003 12:50 PM
He's human: has brainfarts like the rest of us.