SHIMANO Bottom Bracket BBR60-68mm English Thread.

Product Information

Although the BB30 and PF30 standards have been widely adopted, there’s still a little distance between the crank arm and the bearing on the non-drive side. So Cannondale is increasingly using BB30a bearings on its more recent bikes. This is essentially the same as BB30, but just moves the left hand bearing outwards by another 5mm, adding a bit of extra crank stability.

That extra 5mm can complicate crank compatibility, however. BB30-compatible cranks that feature axle spacers on the non-driveside (such as from Cannondale and SRAM) will work just fine because all you’ll have to do is remove spacers as needed to accommodate the extra width, but BB30 cranks without such spacers (such as from FSA and Specialized) won’t work. Our] Hollowgram SiSL2 crank with SpideRing weighs 484g. By comparison, Dura-Ace 9000 weighs around 678g [we recorded 637g in our review – ed]. In addition to weight, another BB30 advantage is stiffness. By increasing the spindle diameter, you increase its resistance to twisting, which is where the bulk of the deflection in a crankset comes from. Roughly 70% of total deflection measured at the pedal comes from axle twist.”BB shell width 86.5mm road, 91.5mm MTB. Other widths may be named according to shell dimensions: 89.5mm, 104.5mm, 107mm, 121mm, 132mm Cranksets with 30 mm wide spindles won’t fit into frames with BB86, or BB90 BBs, but with correct BB some can be made to fit into threaded frames. If everything is manufactured as intended, we shouldn’t be dealing with creaking as much as we are currently Specialized‘s OSBB system is nearly identical to BB/PF30 but with a few key differences, according to the company’s director of advanced research, Chris D’Aluisio.

Specialized uses PF30 for its high-end mountain bike, confusingly also calling it OSBB though it is a different standard to the OSBB standard found on its road bike. BB30 and PF30 cranksets won’t fit frames with different BB shell standard, because their spindle will be too short. Brown, Sheldon. "Bicycle Glossary: Retainer" . Retrieved 2010-03-26. The advantages of retainers are ease of assembly, and economy because the manufacturer can get by with fewer balls, if they are spaced apart by a retainer. The need for a heavier metal interface looked like a limiting factor for mass-produced carbon bikes, but with a manufacturer like Trek on now on board (as mentioned above, its 2020 Domane features a T47 BB) that could all be about to change.

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.

BMC / Bianchi / Bulls / Canyon / Cube / Giant / Ridley 2019 onward / Scott / Sensa / Cannondale / Koga / Lapierre / Stevens

Why are there so many bottom bracket standards?

There are a few standard shell diameters (34.798–36mm[1.3700–1.4173in]) with associated thread pitches (24–28TPI). Earlier three-piece cranks consist of a spindle incorporating bearing cones (facing out), a fixed cup on the drive side (with a cone), an adjustable cup on the non-drive side (also with a cone), and loose bearing balls (or held by a cage). Overhauling requires removing at least one cup, cleaning the cups, cleaning or (more usually) replacing the bearing balls, reinstalling the spindle, and adjusting the cups. The design is nowadays mostly found on affordable bikes due to its simple and affordable design, and is also an easily serviceable design. Other notes Analogous to BB30 above, but uses pressed cups (with identical bearings) for relaxed manufacturing tolerances OSBB (Road)