BB30 Bottom Bracket

milanino-branca

Hi All
I have recently purchased a FSA Gossamer BB30 chain set which i would like to fit to a 68mm bottom bracket shell which has an english thread. Is it possible to use a press fit bottom bracket in a threaded bottom bracket shell or are the diameters of the shell totally different?
Many thanks

MB

mitchgixer6

Unfortunately that's not possible.

milanino-branca

Thanks for your reply…..that was the conclusion I had come to myself but wanted it confirming.
Cheers

mitchgixer6

Was looking for an adaptor myself last night (BB30 to Hollowtech 2) and stumbled upon this. On first glance it looks like it will do what you are needing, allow a BB30 crank to go into a BSA threaded frame.

Might be worth checking with Sigma, but it certainly looks like this is now a possibility when before it was always the case this couldn't be done due to the differing sizes of the axles.

Good luck!

http://www.sigmasport.co.uk/item/Rotor/ ... QE?wmp=115

sungod

pretty sure the rotor cups won't work with a *standard* bb30 crankset...

rotor's cranksets have a longer spindle than bb30 specification, on a real bb30 bb they use spacers to take up the slack, this long spindle allows them to work on a bsa frame using these cups

but a pure bb30 crankset will not be wide enough

Monty Dog

Yup, the Rotor 30mm crank has a longer spindle to allow you to use them with a regular 68mm BB shell.
The internal diameter of a 68mm shell is 42mm, a BB30 spindle is 30mm diameter which leaves 6mm either side for the bearings - by the time you add a couple of mm either side for the cups, you've got 2mm left for bearings (traditional loose-ball BBs use 1/4") which means they would probably last about a week...

milanino-branca

Thanks Mitchgixer6 for the thread to Sigma……it may have worked but the spindle is not long enough in this case.
Thanks all for your help