Other notes Similar asymmetric concept as Cannondale Ai, but the shell is wider BBRight (Press Fit) Other notes Essentially the Pressfit version of BB30A and BB30-83 BBRight (Direct Fit) An older 84.5x46mm BB appears to be obsolete. Other notes OSBB for mountain bikes appears to be PF30 (post 2010). An older Pressfit 61x46mm BB appears to be obsolete OSBB (Mountain) Other notes OSBB for Specialized Road bikes appears to just be BB30. Installation Pressed 6806 bearings with circlips in BB shellĬompatibility Designed for specific BB30 cranks Other notes Analogous to BB30 above, but uses pressed cups (with identical bearings) for relaxed manufacturing tolerances OSBB (Road) Wider overall shell is also claimed to improve bearing support PF30Ĭompatibility Originally designed for BB30 cranks Other notes Asymmetric BB shell which is wider on non-driveside. Other notes Narrow overall width means longer spindles can be used with appropriate spacers BB30A and BB30-83 AiīB shell width 73mm (BB30A), 83mm (BB30-83) Installation 6806 bearings pressed into frame with circlips to locate in BB shellĬompatibility Designed for specific BB30 cranks, 24mm step-down spacers available Proprietary? No (open Cannondale standard) Other notes Similar to above, but a non-proprietary version with less stringent tolerances BB30 Other names PF41 (Hope – refers to BB shell diameter), PF24 (Chris King – refers to spindle diameter) Other widths may be named according to shell dimensions: 89.5mm, 104.5mm, 107mm, 121mm, 132mmĬompatibility Originally designed for 24mm spindles, but some BBs that fit a 30mm spindle are available Other notes The extra width of the BB cups is replaced with more frame real-estate BB86/BB92īB shell width 86.5mm road, 91.5mm MTB. Installation Pressed bearings with stepped BB shellĬompatibility Designed specifically for 24mm spindles, no 30mm option

Other notes Can be prone to undoing itself because non-driveside is a standard thread BB90/BB95 Other notes External cups now exist that will take 30mm spindles Italian threadedīB shell inner diameter 1.375in (34.92mm) x 24 TPI

Other notes Bottom bracket must be specced with correct shell width and spindle length ISO threaded externalīearing inner diameter 24mm (Hollowtech II), 24/22mm (GXP), 25mm (Ultratorque/Powertorque) Road bike groupsets: everything you need to knowīottom bracket standards and compatibility ISO threaded internalīearing inner diameter N/A, internal BBs have integrated spindleīB shell width 68mm road, 73mm mountain, 83mm downhill, 100/120mm fat bikeĬompatibility Square taper, Octalink, ISIS.Before we get stuck into the nitty-gritty of each standard though, we’ve put together this helpful crib sheet that runs through all of the key specifications.

The new chopper builders handbook