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View Full Version : BB30 vs pressfit30

soulspinner
11-14-2011, 05:19 AM
Recently talked to a builder who says he does bb30 because he can make tolerances for it and feels pf30 is inferior. Couldnt really understand this. All I got is the spindle is 30mm and then youll find out if the frame is stiff . Anybody understand the difference?
cfox
11-14-2011, 07:08 AM
I like PF30 better. Both "standards" allow the larger spindle, but in PF30 the bearings go in external, press-in cups vs bb30 where the bearings are pressed directly into the BB shell and held in with clips. Having external cups take the bearing wear rather than the frame itself is better. The cups are easily replaced and there is no risk of the bearings ovalizing the BB shell (google 'BB30 creak') and ruining the frame. Also, for the frame maker, the tolerances don't have to be nearly as close, as the PF30 shell is simply reamed and faced after the frame is built.
oldpotatoe
11-14-2011, 07:27 AM
Recently talked to a builder who says he does bb30 because he can make tolerances for it and feels pf30 is inferior. Couldnt really understand this. All I got is the spindle is 30mm and then youll find out if the frame is stiff . Anybody understand the difference?

Biggest issue we see is poor quality bearings in many PFBB30 BBs. Altho Wheels is making a better one now.

A ti builder told me BB30 in a metal frame is really difficult because the shell warps some when welding making the shell distorted some, making the BB30 bearings not quite square.

Wait, I have an idea...just machine a tube, weld it together then thread it...you know get the BB makers to make a set of cups with threads.........
Lovetoclimb
11-14-2011, 07:35 AM
Wait, I have an idea...just machine a tube, weld it together then thread it...you know get the BB makers to make a set of cups with threads.........

No way this will ever catch on . . .
eddief
11-14-2011, 08:31 AM
http://www.universalcycles.com/shopping/product_details.php?id=29424
45K10
11-14-2011, 02:21 PM
Run away from BB30. I finally had enough, after going through two frames and numerous bearings I pressed in a threaded adapter and went with a Chris King external BB. No problems since. I really do not see the advantage of the BB30, weight savings I guess. I could not tell any difference in stiffness.
sg8357
11-14-2011, 02:31 PM
No way this will ever catch on . . .

I predict carbon fiber Ashtabula will be the next weeks BB standard.
eddief
11-14-2011, 03:10 PM
just curious.

Run away from BB30. I finally had enough, after going through two frames and numerous bearings I pressed in a threaded adapter and went with a Chris King external BB. No problems since. I really do not see the advantage of the BB30, weight savings I guess. I could not tell any difference in stiffness.
oldpotatoe
11-14-2011, 03:47 PM
I predict carbon fiber Ashtabula will be the next weeks BB standard.


Been done

http://www.bing.com/images/search?q=Look+carbon+crank&id=7E77158BD828BC956EFE8F4278DC86846D8E3B2E&FORM=IGRE1
kramnnim
11-14-2011, 04:47 PM
Been done

http://www.bing.com/images/search?q=Look+carbon+crank&id=7E77158BD828BC956EFE8F4278DC86846D8E3B2E&FORM=IGRE1

Hey, a fellow Bing user...

I wondered how those Look cranks work...very odd. The pedal insert thing...does it act as a nut on the pedal spindle?
oldpotatoe
11-14-2011, 05:19 PM
Hey, a fellow Bing user...

I wondered how those Look cranks work...very odd. The pedal insert thing...does it act as a nut on the pedal spindle?

Don't know, just seen pix..carbon astabula..yikes.