Bottom bracket size??

noppy

Hi,

im changing my crank over to a new frame.
the bottom bracket on my old frame is 68/118
the measurment on the new frame is 73mm so do i need a 118 or a 121?

Thanks

nicklouse

Same as before.

noppy

cheers.

now i just have to wait for crc to get it back in stock

noppy

Hi,

any one have any idea what size i need.

im using the crank of my stumpy which on my stumpy used 68.118

the GT is 73

i was advised on here to get 73.118 but it doesn't fit the crank rubs the frame

nicklouse

and the cranks are?

what chain line does the GT require?

also which year and version of the force.

you should have given all this info first time.

as say the 2012 force has a 150mm rear hub so a wider front chain line is likely.

noppy

XT

and i have no idea just googling now
but cant seem to find it

supersonic

What type of chainset? External botoom bracket, octalink?

nicklouse

noppy wrote:

XT

and i have no idea just googling now
but cant seem to find it

part number? there are lots of XT cranks.

topics merged.

noppy

ok thanks its the 08/09 gt force 1.0

135mm rear axle

cranks are off a 04/05 stumpy. cant find part number on it

noppy

its an octalink .

the only other options are 121 and 126
i dont think 1.5mm either side would make any difference. so surely that means it would be the 126 using this logic?

nicklouse

back of the arm.

noppy

bg175 fc m540

that it ?

supersonic

If is a 73mm shell then you should use a 73mm bottom bracket. It uses a 121 or 126mm bottom bracket for 47.5 and 50mm chainlines.

nicklouse

sounds like it had a wrong sized BB in before.

FYI. FC M540 is the part number and the 175mm is the crank (arm) length.

noppy

oh on the stumpy when i replaced it i just got what was in there before i owned it :?

Thanks guys il for the 126 im pretty sure a 121 wouldn't fit space wise.

and thanks nicklouse i shall remember that in future so does the m540 actually mean anything or is it just the part number?

cooldad

The model number