The demand for ceramic bearings has grown so fervent that we spend less and less time explaining the benefits of going ceramic and far more time apologizing for hardly having anything in stock. We've rarely seen such a sustained period of demand outstripping supply. The reasons behind the ceramic demand, though, are obvious: The hardness and roundness of ceramic bearings (not to mention the cost-is-no-object lubrication bathing them) leads to a measurable decrease in mechanical resistance. And unlike considerations of aerodynamic resistance that take on more consequence as your riding speed increases, mechanical resistance is a linear phenomenon: The drag of inferior bearings in your BB and hubs slow you down equally at 8mph as they do at 28mph. Ceramic hub bearings, for example, have been shown to provide reductions in drag on an 8% climb equivalent to dropping 340g from the weight of your bike. You don't need a degree in Engineering to understand the impact this has on your performance.

Up until recently only one company out there was aggressively marketing ceramic bearings: FSA. Their bottom brackets and hub bearing upgrade kits were amongst the hottest items we sold last season. Our periodic lack of availability was a function of FSA's production cycles. They could afford to produce bearings as they saw fit: They were the only game in town, and our frustration with their spotty availability brought about a necessity-is-the-mother-of-invention situation. To wit:

We'd long retro-fitted Dura Ace 10-speed external bearing bottom brackets with Phil Wood bearings in order to decrease their drag. A light bulb lit above our heads one day: Given that we'd invested in a Phil bearing press, why not take our retro-fitting phenomenon to the next logical level by installing not Phil bearings, but ceramic cartridge bearings instead?

Our idea holds fantastic merit for three reasons:

(1) The ceramic bearings we install in these Dura Ace ceramic BB's are of identical quality to what you get from FSA. Your performance gains will be equal.

(2) Most people who purchase the FSA ceramic BB's from us are in fact using them on Dura Ace 10-speed cranksets. The inner sleeves of an FSA BB were designed around FSA cranksets (which has subtle-but-meaningful design differences from Shimano), so it required the tedious trial and error of removing and re-installing seals and sleeves in order to minimize the drag between the FSA BB and the Dura Ace crank. It's an annoying process, and by going with a Dura Ace BB, compatibility is assured.

Our Dura Ace BB's are, of course, made specifically for use with Dura Ace cranksets (and they're also compatible with Shimano's Ultegra and 105 10-speed cranksets). By keeping your drivetrain full Dura Ace, you're assured of top-notch performance.

(3) We're not doing this in violation of any Shimano dictates. While they'd never admittedly approve of a retro-fitting process like this, we made them aware of our plans and they gladly supplied us with a truckload of BB's. Thanks to the fact that we have a precision bearing press, and thanks to the fact that removing the original Dura Ace bearings and installing our ceramic bearings is such a clean and easy job, they saw no reason to frown on our procedure.

Competitive Cyclist will provide a 3-year warranty for our retro-fit ceramic Dura Ace BB's (the same length as a standard Shimano BB warranty). Not only will we supply you with a ceramic Dura Ace bottom bracket ready for installation into your bike, but we'll also supply you with the original Shimano Dura Ace bearings we removed from your BB.

This BB is for bicycles with English (68) threads. This includes most brands sold today, including Cervélo, BMC, Trek, Cannondale, Specialized, and Giant.