The most significant [advantage] is a stiffer frame,” says Trek mountain bike product manager John Riley. “Secondarily, BB90/95 offers a lighter overall solution by replacing traditional alloy bearing cups with integrated carbon bearing bores. It also provides a simplified installation process.” If the frame has a press-fit BB shell (without threads, threadless), then you need quite expensive, special tools to install and remove/change BBs. If not using such tools (like a bearing press), bicycle frame can be damaged. There are three current Hollowtech II road threaded BB designs (different model numbers of identical designs also exist).

The explosion of standards is not good for consumers or dealers,” Doyne continues. “The bottom line is that bike companies are driving the standards. Threaded systems have very few limitations — they are easily cleaned and repaired at the shop level, and they do not affect the bearing fit.” Campagnolo Ultra-Torque Crankset". 2006. Archived from the original on 2007-01-04 . Retrieved 2006-12-14. It also means that the axle diameter can be increased to 24mm, which increases axle stiffness. The axle is hollow, which reduces the weight too. The bearings are usually housed in sealed races, which makes them easy to remove or replace. And there’s a really solid interface between the bearings and the frame, which should eliminate creaking (see later). British Council Film Collection - How a Bicycle is made". British Council Film Collection. 1945. At 03:25 . Retrieved 2016-03-16.I've taken apart a brand new BBR60 bought from Merlin as it was defect and wouldn't spin properly. Of course they thought it was my fault, my loss, so I took it apart for 'science'. Chain reaction Cycles and CRC are trading names of Wiggle Ltd (In Administration) registered in the United Kingdom at 1000 Lakeside, Suite 310, Third Floor N E Wing, Portsmouth, Hampshire, PO6 3EN, More recently, bearings have shown up that allow a 30mm spindle to be used. The dimensional restriction mean the bearings are generally quite small, as the system was designed around 24mm spindles. This can lead to reduced bearing lifetimes. Other notes Aims to solve creaking issues of press fit systems. Essentially an oversized BSA external BB Thread Fit 82.5

BMC / Bulls / Canyon / Cervelo / Cube / Focus / Giant / Ridley 2019 onward / Scott / Sensa / Trek / Cannondale / Koga / Lapierre / Specialized / StevensTrek’s BB90 system uses the same bearings and bearing locations as a conventional threaded system, but eliminates the cups entirely. Bearings are pressed directly into precision-molded carbon seats Immediate Media

Schlumpf Innovations: Mountain Drive". 2005. Archived from the original on 2007-10-30 . Retrieved 2007-11-18. The idea is simple, by moving the bearings outboard of the shell, you can then use a much larger spindle. Currently, 24mm is the accepted norm compared to square-taper’s relatively minuscule 17mm diameter. Pros: Same as BB30 but with lower costs, easier assembly, and the potential for additional bearing seals integrated into the cup/bearing assembly

BBRight bottom brackets

Crank designs that will fit: Standard 24mm external type (Shimano Hollowtech II, SRAM GXP, Campagnolo Ultratorque and Powertorque, FSA MegaExo, Race Face X-Type, etc), square taper, ISIS, BB386EVO, BB392EVO many others. Crucially external cups that fit 30mm spindles do exist. Cons: Heavier than press-fit systems; frame design limited by relatively small-diameter and narrow shell