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

[moonoi]

No it's not a bb30, still osbb, what most conversion bb systems use the bb30 version of their adapters with some spacers to so they can be fitted.

Check the wheels manufacturing site, they have a lot of detail on it.


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[bikerjulio]

Yes it's BB30. This thread may be of interest http://forums.roadbikereview.com/specialized/2016-tarmac-bb30-issues-352540.html

[mpulsiv]

OSBB is refined version of BB30. It comes with with tighter tolerances and a 0.5mm difference in the clip-to-clip dimension.


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[moonoi]

Hence the need for the spacers.

So basically what we're saying is it both is and isn't BB30 :-p


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[kulivontot]

Picture is worth at thousand words

[bikerjulio]

From the thread I linked to. The writer has made a career of writing about Spec BB's

Specialized made a big change in 2015. After years of struggle, they discontinued their narrow version of PF30 they called carbon OSBB. They made this exclusively for their top Sworks frames across many models and honestly shame on them for building and selling it as long as they did. PF30 is the absolute worst and they finally shamelessly abandoned it as a selling point for their most upscale Sworks bikes which was a huge deficit and not a benefit. Marketing at its worse.

OP, you are very smart to ask. The BB is the centerpiece of any bike. Good news is...Specialized latest default BB is BB30 which is light years more reliable than PF30 but not as rock solid as English threaded with an external bearing crank like Ultegra or DA...latter is the most bullet proof and dependable combo in the industry.

[goodboyr]

"Roadworthy".....

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[GorrGrimWolf]

As the others has correctly pointed out the OSBB could be either regular BB30 or worse the "specialized" PF30. Their version of PF30 is about 7mm narrower than normal PF30.

If you see aluminium in BB than its BB30, if you see just carbon you know you its theirs PF30. Both can actually be quite reliable but you need to use Praxis conversion kit. Yet it doesn't guarantee silence/maintenance free service for 100%, especially if the BB is out of tolerances. But if you plan use GXP/Campa cranks, it is your best bet. But it is not a weight weenie solution by any means...

[bikerjulio]

"Roadworthy".....

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A most knowledgeable fellow

[goodboyr]

Lol. Good times.....

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[bikerjulio]

As the others has correctly pointed out the OSBB could be either regular BB30 or worse the "specialized" PF30. Their version of PF30 is about 7mm narrower than normal PF30.

If you see aluminium in BB than its BB30, if you see just carbon you know you its theirs PF30. Both can actually be quite reliable but you need to use Praxis conversion kit. Yet it doesn't guarantee silence/maintenance free service for 100%, especially if the BB is out of tolerances. But if you plan use GXP/Campa cranks, it is your best bet. But it is not a weight weenie solution by any means...

OP started out by saying

2015/16 frame so has metal cups bonded in the frameset

which when read with the quote I posted earlier indicates that Spec had abandoned their "OSBB" and gone over to plain old BB30.

BTW a BB30 with tighter tolerances is still BB30.