gregf83 

Another vote for the Praxis BB. I have a Boardman cyclocross bike that came with a Gossamer crank. When it started to creak I replaced the BB with Praxis and installed an Ultegra crank. No problems since.

Kimmo 

I'd say if you have a frame that can take a 30mm crank in a 68mm shell without external bearings, then you should take advantage of the extra heel clearance offered by a BB30/PF30 crank.

Campag4life

To me, heel clearance isn't a problem with an outboard bearing BB but this is written from time to time. To me more an indictment against poor pedaling mechanics. Don't want to say Q-factor is a myth but for better cyclists pretty much a non issue independent of whether they are slew footed walking down the street.

This thread does beg a larger design issue of course which hasn't been discussed much. Conversions. Yes, why companies like Praxis and Wheel Manufacturing came into being and even old companies like Chris King that also capitalized on the high end segment of the conversion market.

What would I do? I am a gearhead and see the inherent goodness or not in design. Others struggle in this regard. Reality is...of all the press fit BB's out, BB30 is among the best. Why? How it is made...with carbon bike, a machined Al cylinder very precisely machined is insert molded into the carbon. Bores are very co-axial and bearing diameters are held to tight tolerance.

So for $20 versus $90 and a bottle of Loctite and even average mechanical skills...this ain't a valve adjustment on a 4 valve Ducati....BB30 bearings can be installed and perfectly tamed and very cheap to run over the life of bike ownership. Many fail in this effort. They can't make BB30 not creak. They can't follow the recipe...or don't want to. That is where Praxis comes into being.

For me, I would run a BB30 crank on a BB30 frameset and I am sure like I have helped so many, I could build it and it would be church quiet.
1. Fresh cheap BB30 bearings

2. Loctite

3. Assemble with slightly overtorqued preload (if mechanical preload) and let cure overnight...this aligns the bearings in the bores. In any event, assemble the crank to the bike before the Loctite sets.

4. Readjust preload to hand tight in the morning. Btw, Shimano cranks work perfectly with Wheel Mfg spacers with BB30 bearings too. If BB30 bearings are Loctited which they should be, if there is a rattle, then mechanical preload is misadjusted...its the Whl Mfg spacers rattling between bearings and crank spindle. In fact, even using grease instead of Loctite with a Shimano crank on BB30 bearing bike, a Shimano crank with BB30 and Whl Mfg spacers most likely will not creak. This is because mechanical preload can be snugged to the point to take all lateral bearing creep and therefore creak out of the system. Where people get it wrong is they don't know how to adjust preload.

Difference between quiet and creaky cranks are simple steps which some including bike shop mechanics can not adhere to...human nature which has spawned a cottage industry of companies like Praxis to convert how bikes are sold to consumers that people struggle with. Kind of a sad commentary. Ferrari's sold to consumers they can't figure out how to tune to run right. But if you understand the nature of the parts involved and their relationship, BB30 with Loctite and adequate crank spindle preload can NOT creak...nothing to creak.

Lastly, too much spindle preload prematurely kills BB30 bearings everyday. If you buy BB30, ABEC-3 to 5 bearings for a baseline of quality, opt for angular contact which can be purchased cheap...much cheaper than pretty much any BB on the market including Shimano's excellent BSA bearings/cups most of us prefer. BSA for the win as most would agree.

cruiserhead

That's their only advantage over Dura Ace- lighter weight

The best BB30 crankset is the SISL2 Spidering.

deacon mark

My Brother Tim is spot on...…………...you want a Praxis and be done. Many bikes now seem to come with them already installed on the cranks. Now if they would just return to a threaded BB we could be on our way. Shimano I say still makes the best cranks and the smoothest shifting. This is one part of the bike I do not compromise. I want Shimano Cranks, chain, derailleurs, shifters they work together just great and you shift all the time so why be hassled trying to save a buck. Get cheap bartape, even less expensive wheels ( heresy for some), cheaper computer, but if you ride a road bike you shift gears all the time and you don't want high maintenance.

DOS