Installing external bb cups with no bb tool

kumate_champ07 · 12-07-2011 10:47pm #1

I just fit an Sram gxp crankset, I installed the cups by hand, then fit the cranks. Theres no play at all so it seems good to go.
Should I wait till I get the right tool or is it fine?

Morgan · 13-07-2011 6:17am

At the very least I'd expect it to creak like mad. BB cups have the highest torque requirements of any fixing on the bike (off the top of my head), hand-tight won't cut it.

Lumen · 13-07-2011 7:31am

..second only to the damn cranks.

http://bicycletutor.com/torque-specifications/

GXP BB
33.9-40.1 Nm
300-360 in lbs

Powerspline cranks
38-42 Nm (actually my SRAM Red cranks say 48-54)
336-372 in lbs

(goes off to tighten creaky BB)

kumate_champ07 · 13-07-2011 8:47am

I do have a very strong grip tho, Ill buy the tool today for peace of mind.

Lumen · 13-07-2011 8:59am

kumate_champ07 wrote: »

I do have a very strong grip tho, Ill buy the tool today for peace of mind.

If you had enough grip to generate 40nm on a BB cup you would probably rip your skin off. I tried it once with a strap wrench and that wasn't enough.

GTDolanator · 13-07-2011 10:27am

meh if your not going to get upset by a few scratches just use a pipe grips,thats all ive ever used with externals and i dont get no creaking or coming loose and im on the bike everyday

C3PO · 13-07-2011 11:40am

GTDolanator wrote: »

meh if your not going to get upset by a few scratches just use a pipe grips,thats all ive ever used with externals and i dont get no creaking or coming loose and im on the bike everyday

Or maybe just a hammer and bolster chisel would do the job? :rolleyes:

Installing external bb cups with no bb tool

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