BB90 standard is introduced by Trek in 2007 and followed with the mountain bike version BB95.
Instead of bearing pressed into the bottom bracket cups and then into the frame, BB90 bearings are pressed directly into the frame shell (ID 37mm).
Bearing seats are moulded into the frame shell to save the weight. The bottom bracket shell width is 90mm on road bikes and 95mm on mountain bikes. BB90 uses 6806-7mm bearings, as same as the external thread bottom bracket, that can mount 24mm spindle Shimano crankset or SRAM GXP 22-24mm without any issues.
– BB90 system is first introduced by Trek
– Super light system, no extra weight sacrifice for the BB cups
– ABEC 7 standard alloy steel bearing races
– Grade 3 Si3N4 ceramic balls – highest precision in the market
– Kluber grease
– Specially designed Nylon bearing retainer for more shock absorbing and less friction
– Light touch rubber seals – super smoothness
– 38g for Shimano crank
– 45g for SRAM GXP crank
– 2 x HSC hybrid ceramic bearings, 2 x plastic dust shields
– BB90 standard frame (bearings directly pressed into the frame) with shell ID 37mm, width 90mm
e.g. Trek Madone series, Trek Madone series,Trek Madone series, Trek Domane, Trek Speed Concept series, Trek Cronus CX Ultimate frames; Willier Cento frames etc.
– 24mm spindle cranks, e.g. Shimano Dura Ace, Shimano Ultegra, Shimano 105, Shimano Tiagra, FSA etc.
SRAM Rival/Force/Red and Bontrager GXP Cranks (HSC SRAM adapter included)