Singlespeed & Fixed Gear - Shimano 105 Cranks, bb length?

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benoist
04-13-07, 10:37 AM
Any tips on the appropriate BB length for shimano 105 cranks (square taper double)? I'd like to be able to mount a rocket ring on the outside.

Thanks for the tips...

AfterThisNap
04-13-07, 11:14 AM
prolly a 103 on a track frame, otherwise you're just going to have to experiment.
Cynikal
04-13-07, 11:34 AM
Just a FYI, rocket rings blow. Spend $15 more for a salsa.

mihlbach
04-13-07, 11:46 AM
I have a 113 mm BB with the ring on the inside of my square taper 105s with about a 41mm chainline. If you want to put it on the outside, you'll need somewhere near 103mm spindle.

FYI...I had to do some dremeling to get my rocket ring to fit on my 105s, but once I got it to fit, it works very well...smooth and very round without a notable tight spot.
dobber
04-13-07, 04:00 PM
The nominal bb for the 105 was 113 or 107 depending on the year and gave you a 46 outer or 41 inner chainline. You'll need to take about 4mm off a side or get a bb that's about 8 mm shorter then the nominal.


http://www.sheldonbrown.com/bbsize.html#chainline
mander
04-13-07, 04:27 PM
The 107mm shimano bb puts my 600 cranks' outer ring position at just a bit more than 42mm, and I see the earlier 105's have the same chainline as the 600's. If you do have the older, seven speed 105s (full name: 105-SC 1055) you'll be in business with a 107mm jis spindle.

http://www.sheldonbrown.com/bbsize.html#105

http://www.sheldonbrown.com/bbsize.html#ultegra