Why We Make It We build bearings, so we build bottom brackets. The humble threaded bottom bracket is often the first part installed on a new frame, and the last one the rider thinks about during the life of the bike, but the bottom bracket has a direct effect on pedaling efficiency (read: speed). This is where you put your power into the bike. Having the absolute best interface between your effort and your bike's forward momentum makes your ride better. The Threadfit(TM) 24 is how we make bikes that take 24mm cranks the best they can be. Why You Want It ThreadFit(TM) 24 fits 24mm cranks in BSA bottom bracket shells. Our ThreadFit(TM) 24 bottom bracket is designed and built to be durable, serviceable, and silent. Manufactured to create the most precise interface between your frame's bottom bracket shell and your cranks, it makes your cranks spin lightly and easily, without interference, for the lifetime of your bike (with a little regular service). King's legendary, angular-contact bearings, both steel and ceramic, are the best in the industry, and actually get faster over time, as their contact surfaces wear. You want this bottom bracket because it offers super low drag. You want this bottom bracket, because it can be opened, cleaned and repacked for years of faithful service. You want this bottom bracket, because you don't want to think an awful lot about your bottom bracket. Our Threadfit(TM) 24 bottom brackets come in an array of beautifully anodized colors and each one includes a Fit Kits that allow our ThreadFit(TM) 24 to be used with a wide selection of road and mountain bike cranks. - Engineered, manufactured and assembled in Portland, Oregon USA - King Lifetime Warranty - Legendary made-in-house bearings - Available in 8 beautifully anodized colors - A Fit Kit is required for use - Ceramic bearing upgrade available