Bottom bracket size.

froque said:

hello

I am going to install a shimano tiagra triple crankset (Taper-fit or square type) onto a hybrid bike, it is a 135 mm spaced frame.

My question is which lengh of bottom braket shall I buy to have a proper chainline?

Thanks

felroq

My crystal ball says "404 Page Not Found". Need schload more info before commenting such as what kind of frame.....

capwater said:

My crystal ball says "404 Page Not Found". Need schload more info before commenting such as what kind of frame.....

If you tell me what else you need I will try to post, but I think I have said what is necesary or not? Hybrid frame (700C), 135 mm spaced ( mtb standard hubs), Shimano tiagra tapper-fit triple cranks.

BSA bb shell, but that really does not matter with the BB lenght, or not?

Thanks.

felroq

froque said:

If you tell me what else you need I will try to post, but I think I have said what is necesary or not? Hybrid frame (700C), 135 mm spaced ( mtb standard hubs), Shimano tiagra tapper-fit triple cranks.

BSA bb shell, but that really does not matter with the BB lenght, or not?

Thanks.

felroq

You are correct that BB shell width does not affect spindle length but BB shell width matters in selecting the correct BB for your bike because some MTB frames have 73mm BB shells. You probably have a 68mm with English thread, but without a measurement, one can't be sure. The 135mm rear hub spacing does not affect BB selection. Some hybrids are basically MTB frames that accomodate larger 700C wheels (and could have 73mm BBs), whereas others are road frames made to accomodate the fatter 32-35mm tires (and would likely have 68mm BBs). Thus, because there is no "hybrid standard", the request for more information is not unreasonable.

That being said, I would guess that you need at 68 X 118mm square-taper English BB for that triple.

If you aren't sure of your frame measurements, perhaps listing the brand, year, and model will help some of the "experts" figure it out.

froque said:

If you tell me what else you need I will try to post, but I think I have said what is necesary or not? Hybrid frame (700C), 135 mm spaced ( mtb standard hubs), Shimano tiagra tapper-fit triple cranks.

BSA bb shell, but that really does not matter with the BB lenght, or not?

Thanks.

felroq

Assuming it 68mm english thread, you could be looking at a Shimano UN53. Sheldon Brown says 113mm length for a Tiagra 4403 triple.

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

20 bucks via Nashbar
http://www.nashbar.com/profile.cfm?category=73&subcategory=1096&brand=&sku=8104&storetype=&estoreid=&pagename=

Hope this helps. Good luck.

froque said:

hello

I am going to install a shimano tiagra triple crankset (Taper-fit or square type) onto a hybrid bike, it is a 135 mm spaced frame.

My question is which lengh of bottom braket shall I buy to have a proper chainline?

Thanks

felroq

Cap is probably right about the 113. I was thinking that it was likely to be the same as the 118 for the splined OCTALINK Tiagra triple.