Cannondale developed the BB30 bottom bracket in as an open standard. It used a larger 30mm axle which allowed bigger bearings and a bigger bottom bracket shell, providing extra stiffness and lower weight. But it required a precision machined shell and crank, and was expensive to manufacture with an alloy shell bonded to the carbon frame. Pressfit soon followed in and aimed to address the high tolerances of BB30 by housing bearings in nylon composite cups that are then pressed directly into the frame.
Five reasons why the T47 bottom bracket won’t solve everything
", "Specialized"," Crossroads Cruz велосипед рама с нижней скобкой и гарнитура | eBay
Looking to upgrade or replace your worn-out Specialized bottom bracket? And let's face it, older Specialized bottom bracket specs are confusing for many of us who love this brand. Want to geek out more on Specialized bottom bracket standards? Otherwise, let's break it down and help you find the right BB for your beloved Specialized frame.
Crank & Bottom Bracket
While the design has merit, there are also significant issues that are likely to keep T47 from becoming the one bottom bracket standard adopted by the entire cycling industry. Related: Six reasons to like the T47 bottom bracket standard. According to Mark Norstad of Paragon Machine Works, the go-to parts supplier for many custom frame builders, the T47 bottom bracket shell will come in at least seven different widths. And for what?
I thought for sure it was my bottom bracket as well. Turns out it was my DA cassette. Under heavy load climbing , it would creak and creak. Shop warrantied and replaced the cassette twice.