osbb confusion

thebadgerboy1982

Hi all,

I'm building up a tarmac frameset and I'm pretty confused with the osbb standard. Its a 2015/16 frame so has metal cups bonded in the framset unlike the earlier frames that had a carbon shell.

Is this later version just a bb30 bottom bracket? So i could essentially use any bb30 to shimano bottom bracket rather than just praxis?
Im looking at this one:
http://www.enduroforkseals.com/id384.html

Thanks

sungod

osbb is not bb30, the shell diameter is larger and the width is narrower

if you want to use shimano cranks, you need the appropriate bb, for instance... https://www.evanscycles.com/praxis-work ... r-EV190090

Da_Reverend

sungod wrote:

osbb is not bb30, the shell diameter is larger and the width is narrower

This statement is not true.

Actually, "OSBB" is an ambiguous label that Specialized (only) are using for non-threaded bottom bracket shells. There are different OSBB variants out there, most of which have specs identical to other "standards" like BB30 (just Specialized don't use the common terminology because they are so very special). (To my knowledge, the only Road type OSBB which is really non-standard is the carbon shell type. This one essentially is a PF30 but narrower.)

May well be the bottom bracket shell of your frame is actually a plain BB30 shell - just take measurements (width and inner diameter) and you'll know.

For an overview, have a look at the table attached here:
http://forum.tour-magazin.de/showthread ... ost5107962

sungod

Da_Reverend wrote:

sungod wrote:

osbb is not bb30, the shell diameter is larger and the width is narrower

This statement is not true.

yes it is

thebadgerboy1982

it seems that any s works frame after 2015 is plain old bb30 with aluminium cups already bonded into the frame and is 68mm wide. anything before that is 61m wide and needs bb30 bearings with a set of cups

redvision

thebadgerboy1982 wrote:

anything before that is 61m wide

Jesus, thats gotta cause some groin injuries