They shouldn’t work, just looking at them. Nothing that looks and feels like it came out of a McDonald’s Happy Meal should be capable of ably managing the force going through a bike’s bottom bracket. But Wheels Manufacturing’s ultra-simple BB adapters do work, and they work exceptionally well.
That’s because the adapters, which press into BB30 bearings to downsize the crank axle diameter to either Shimano’s 24mm or SRAM’s 24/22mm GXP standard, are a bit more technical than they appear to the naked eye.
What looks like cheap plastic is actually machine-grade Delrin, perfectly machined to plug-and-play into your bottom bracket. Delrin is not only lighter than aluminum, it’s also much more resistant to creaking. And at 45 grams, plus or minus a few grams depending on spacer requirements, they are an exceptionally light way to adapt a BB30 frame to a Shimano or GXP crankset.
More impressive, though, is the fact that after five months of heavy use, through cold rain in Belgium, thunderstorms in the Alps, the dry heat of Boulder, Colo., and everything in between, they have been utterly silent.
How they work
These are adapters, not a full bottom bracket. BB30 bearings must already be in place in your frame, pressed in by a qualified mechanic. If this first step isn’t done properly, there is no adapter in the world that will function well.
From that starting point — a frame with BB30 bearings pressed, greased, and happily spinning — simply select the proper spacers, with the help of the included instructions, apply them to the Wheels adapters, and then press the adapters into the bearings. Install the crank and the process is complete.
Of course, if a BB30 crankset happens to fall in your lap, the adapters can be easily pushed out to reveal the BB30 bottom bracket you started with.
Our only small complaint is that there is little additional sealing over top of the bearings themselves, as is found on Enduro’s aluminum adapters. There is a plastic seal, but the fit is not particularly tight. We packed our bearings with additional grease and have not yet had any bearing issues, zero noise as of yet, but anyone in an extremely wet climate may want a bit more protection.
The price of Wheels Manufacturing’s BB30 adapters is just as smile-worthy as the silence they’ve provided: $30 for the adapters and all required spacers. Shops can pick up a box set, with multiple adapters and giant piles of spacers for Shimano and GXP cranks, for $200.