My Marin BB creaks with every pedal stroke and it is driving me nuts. I'm in the process of tearing it apart but it is fighting me. Shimano Ultegra 6500 Octalink BB and cranks.

I would much rather be servicing a set of Campy UT cranks at the moment which even though they utilize threaded cups on most bikes are more akin to a press fit.

Grasshopper maybe the creak is not coming from the BB but from somewhere else like the quick releases, BB usually dont creak at each pedaling, usually is in one side and in one position in specific, even could be something lose or even the seatpost that needs grease.

I have had no problems with the BB30. I wish Shimano would make some cranksets for it.

I have a 2011 Serotta with Dura-Ace.

I bought a 1993 Titanium Serotta off Craigslist. The crank was Campy, the shifters and ders were 6500. I wanted 10 speed so I could swap any of my wheels.

I popped off the old crankset, cleaned out the housing and installed a 6700 crank and BB and switched to 10 speed. One night, no adapters, just stuff from my garage. In 18 years BB30 will be a special order item you order on the internet for a premium price because it will be an old abandoned idea.

Most of you are dreaming if you think your awesome guads are dialing up 1600 watts and torquing your English/Italian BB.

My mechanic also mentioned that A BB30 bottom bracket is only supposed to be changed once or twice, after that the tolerances are too high and you will really have creaking.

They need a little more care during assembly and the BB is actually packed at the Cannondale factory so it can be a little hit and miss. If something is gonna go wrong with it you'll see it (or more to the point hear it) within the first few weeks (depending on how much your ride).

Mine started clicking with every turn of the crank (under pressure) and got to a point where I could lean on the pedal (when I was off the bike) and make it click.

Took it back to the LBS and they re-packed it with more grease and its been fine ever since.

Thats just one thing to look out for I suppose...there may be others.

WOW, I thought I was the only Luddite here.

Actually, they got the idea from Klien who also used it for their headsets.

Your mechanic is wrong and you are uninformed and if you have a mechanic, I can assume you don't do your own work.
The problem is crappy bike shop mechanics abound and guys grumbling about BB30 on the internet don't know what they are doing.
A BB30 can take a hundred repetitions of bearing changes. Bearings only need to be 'knocked out' of a BB for replacement and not serviced aka re-greased. Trek in fact has spec'ed a slip fit for their version of BB30. So much for a press fit being essential...which it isn't if there is adequate crank pre-load to keep the bearings bedded...just like the headset which takes much higher axial impact loads. Locitite has a number of different formulations depending on whether a BB30 is tight press, line-to-line or even if there is clearance between BB30 alloy cup ID and bearing outer race OD. A BB30 will certainly last as long as any carbon frame.

Does anyone wonder if the industry guys that brought us the great bb30 and its kin read these posts and feel guilty about what they have done? I think the whole thing was to skip the threading step in the frame building process to save a few bucks?

No because it is more expensive to machine a BB to BB30s tight tolerances than it is to simply thread it.

Its probably a jump ball on that Gchopper. Threads versus tight tolerances for BB30...which btw is why PF30 will over time likely supercede it for most mfrs...a single thru bore that can be molded right into the carbon shell versus insert molding alloy cups and then finish machining them..plus the circlip grooves. The major diameter of a threaded BB still has to be reasonable tolerance for decent thread engagement.
The answer is...mfr's could of grown the thread diameter to achieve a 30mm ID bearing aka BB30 with threads but they determined through exhaustive testing that threads aren't necessary. All the squacking about BB30 is just that.

so what kind of wattage improvement should i notice from going from external bb to bb30?

This is why frame makers were very resistant to BB30; It pushed tighter tolerances onto them and the processes are slower (and thereby more expensive).

40 watts. You will get 40 watts with 170 crank arms. If you have 175's you will get 7 watts. Don't ask me to explain it, it's science. From an academic paper somewhere.

My new frame came with BB30, but I wanted to keep using my Ultegra 6750 crankset. I tought about installing the BB30 bearings and the wheels adapters, but I found these KCNC BB30 adapters that work great...


http://i747.photobucket.com/albums/x...2/IMG_0916.jpg


http://i747.photobucket.com/albums/x...2/IMG_0918.jpg

1 watt improvement.

Yup...that is an effective BB for mounting an external bearing crank to a BB30...but Wheel mfg spacers work very well also.
Either solution will work fine. Ultegra cranks tend to work very well with BB30. A primary reason is the design of the crank with one piece spindle which has adjustable preload...lateral adjustment of non drive arm on the spindle spline...whereas the majority of BB30 cranks have a fixed spindle length and rely on wave washers for axial preload which require a bit more effort to set up properly...and a major source of issues with BB30...people don't use not enough care in set up.

A mere 3000 miles so far on my caad9 but I've got no complaints.

SRAM says BB30 gets you three times the ankle clearance (er, 300%) over GXP. I'm having cleat issues, and think I need my toes angled out more. The problem is, I'm fresh out of ankle clearance. Trying to figure out if I need an entirely new frame in order to get my fit dialed in properly.

Nobody's mentioned it, but does anybody need/use the extra ankle clearance provided by a BB30 setup?

^
Wha? I'd figure out what's going on with your fit first. You might end up buying a frame that doesn't solve your problem.

Plannin' on it, it's just obnoxious that I may have to go to the best fitters in the country again, then maybe buy new stuff, then go see them a third time to get my knees sorted out. The first time I went, he oriented my cleats to put my ankle as close to the BB as possible (toes out), and my knees get worse if I adjust the cleats at all to move my ankles away from the BB.

Anyway, not to hijack the thread. I've seen ankle clearance listed as one of the main advantages to BB30, so I'm just wondering if anybody has benefited from it.

what is your pedal spindle length?

I have BB30 on two bikes, My Aerocat R509 and my Redline Conquest pro. All I can say is that I have change the bearings a few times on each without even a headset press or proper removal tools (I have used a long bolt + washers as a punch and large C-Clamps as presses) I install the Crank Arm to Proper torque and I have NEVER had a creak or sounds from either of them. Atually one time I thought I had creaks coming from the BB30 and it turned out it was actually from me wearing out the bushings in a cheap pair of pedals.

Long and the short of it is: BB30 has been pretty freaking awesome so far, atleast for me.

Yup...where I would look...independent of BB/frame selection. I ride Speedplay which offer different spindle lengths for slew footed riders. I ride Speedplay std spindle length but shoes pushed all the way outboard on cleats as I too am slightly duck footed on the bike and don't like brushing the chain stays.

Do you use Loctite on either bike? Many times BB30 bearings can be dead quiet without it...with full encapsulation of grease and a decent press fit with adequate crank axial preload. If a BB30 is set up properly it can't make noise.