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redearedslider5
08-12-2016, 11:22 AM
can someone explain these bottom brackets to me? i'm familiar with square tapers and the ultra torque systems but what do you do with press fit? do you need special cranks to go with them?

rnhood
08-12-2016, 11:33 AM
BB30 has faces cut in the carbon BB to accept bearings, then the crank slides right through. Diameter is 68mm.

PF30 has a diameter of 61(or62)mm, then cups (bearing holders) are inserted which make it effectively 68mm. Then the crank slides right through.

Its possible there are spacers involved too, I don't know. I stand corrected if anyone knows more, and most here probably do.

My bike has pf30 and with near 60k miles, its been bulletproof so far. But I did need new bearings at 37k miles.

chiasticon
08-12-2016, 11:35 AM
press fit = something is pressed directly into the frame, rather than screwed into it. could be cups, could just be the bearings themselves.

oh, and it sucks.

redearedslider5
08-12-2016, 11:37 AM
so say i want to install something that would mount to a square taper bottom bracket, is there some way to do that on pf30?

tuscanyswe
08-12-2016, 11:41 AM
Yes u could run an adapter which then accept a regular threaded bb of your choice.

redearedslider5
08-12-2016, 11:46 AM
ah, so this is the kinda thing i want?

http://www.ebay.com/itm/FSA-PF30-Frame-To-68mm-English-/371612002356?hash=item5685cd2834:g:iC0AAOSwlHRXIqi 7

rePhil
08-12-2016, 12:01 PM
A couple of decent explanations.

https://www.youtube.com/watch?v=aeYlWxYdl9E

https://www.youtube.com/watch?v=AftPKuX_tyo

rnhood
08-12-2016, 12:07 PM
A couple of decent explanations.

https://www.youtube.com/watch?v=aeYlWxYdl9E

https://www.youtube.com/watch?v=AftPKuX_tyo


Good find and thanks.

lhuerta
08-12-2016, 12:13 PM
http://www.parktool.com/blog/repair-help/bottom-bracket-standards-1

The most important thing to remember about press fit BBs is that that there is no such thing as simply "press fit" ....proper install will demand Loctite 609 or stronger to fill gaps and bond cups to frame, otherwise u will experience the dreaded press fit creak.

p nut
08-12-2016, 12:15 PM
press fit = something is pressed directly into the frame, rather than screwed into it. could be cups, could just be the bearings themselves.

oh, and it sucks.

Knock on wood, I have 2 bikes currently with PF BB's and they've been trouble and noise-free. I have one other bike with an EBB, and it's been great as well.