BB - I need an idiots guide

Colinthecop

In keeping with the N+1 requirement I recently got hold of a lovely S-Works Tarmac frame (an early sl one). My thinking being - for a sunny summer bike and I can learn how they go together for when my Allez hack needs bits replacing.

I've been buying up Ultegra 6700 groupset bits but have yet to buy the cranks/chainrings mainly because I quite fancy going for an S works or a FSA set - purely as it looks better. :?

So anyways, every time I read an advert for a set of cranks some new numbers for BB's are thrown into the equation, numbers which I have no idea what they mean. Then I read that my frame has an OSBB which doesnt really help. :roll: Then some adverts say that S works cranks require a press fit BB - but my S works frame is threaded.

Now apparently my frame takes a british threaded BB, but then I read it takes an English threaded BB not a british one - Jeez, I thought it was Itallian or Brit. But I read this on the internet and remember the quote from Einstein that said, 'Just because it's on the internet, it doesnt mean it's true'....

Sorry, i'm rambling now. In summary, i've read too much, i've got confused and I need an idiots guide to bottom brackets to keep me right.

nicklouse

Read the standards on Parktools.

Threads there are 2 types. Italian which is just wrong. And the correct version English,BSA,MTB, yes there are other threaded BBs but get tend to be old so let's forget them

The rest are press fit some use cups some don't some have 24mm diameter axels in then others have 30mm versions. Bigger does not fit smaller. Press fit does not fit a threaded.

Press fit frames can be converted to a sensible bb if required.

Have fun.

Iamnot Wiggins

Right, the Tarmac BB is specialized's own system known as Over Sized Bottom Bracket (OSBB) and the frame shell is slightly narrower than on other frames.

You can run a PF30 bottom bracket in the newer frames without any issues at all.

As for a threaded shell, I'm 99% sure that Rotor will make something to fit as they seem to for everything. Email the guys at Velotech Services for a bit of advice.

Or just have a look here - http://www.velotechservices.co.uk/shop/ ... 7416002009

dennisn

nicklouse wrote:

Threads there are 2 types. Italian which is just wrong. And the correct version English,BSA,MTB, .....

Sort of off topic but what's with the "just wrong" comment? I've never had an issue with Italian ones. At least not with the outboard bearing style. Square taper? Well, maybe they were a bit more, shall we say, trickey. I do note that nowadays even many Italian frames are English.

majormantra

If it's threaded, your easiest option is any 24mm spindle crank (i.e. not BB30/PF30) with the appropriate BB. All major manufacturers make them.

If you want to make your life more complicated/expensive, you could also fit a BB386EVO crank or Rotor BB30 crank with the appropriate BB.

Personally I'd just get the Shimano. BBs are dead cheap and they shift great.

schlepcycling

How about BR's very own BB guide http://www.bikeradar.com/gear/article/complete-guide-to-bottom-brackets-36660/
I found this video for all the pressfit standards very useful too http://www.youtube.com/watch?v=AftPKuX_tyo
Also with regard to the 'dodgy' Italian thread comment the new Pinarello Dogma 8 has one

Colinthecop

I can see all the words, individually they make sense but put them together they become Norwegian.

And I don't speak Norwegian.

I've just ordered an Ultegra 6700 British BB and i'm looking for Compact 6700 cranks. They should fit and i'll play it safe. Something sexier will have to wait until I learn Norwegian.

Thanks for your replies regardless of my stupidity. 8)