BB 386 EVO is one of those ‘standards’ that has been slow to take off, but enough manufacturers seem to be using it by now that bottom bracket makers have taken note. The key difference is the addition of bottom brackets specifically for 24mm or 24/22mm spindles like those used on standard Shimano or SRAM cranksets. Previously, most manufacturers simply made their bottom brackets to fit 30mm spindles and then offered reducer adapters to allow for the use of 24mm spindles.
But with enough frames running the standard and many riders wishing to run Shimano cranksets, or simply not upgrade to a 30mm spindle crankset, we’re seeing a few new options like the new bottom brackets from Wheels Manufacturing. EB17: Wheels Manufacturing adds 386EVO bottom brackets for 24mm spindles, T47 internal and external BBs
Fitted with angular contact bearings, there are two specific models – one for 24mm spindles (Shimano, or others), and one for 24/22mm spindles (SRAM. Using their threaded shell design, the two halves of the bottom bracket thread together in the center keeping everything tight and square in the BB shell. The design also allows for more space between the BB shell and the center of the bottom bracket which should be better for frames with internal cables or wires that run under the BB. Claimed weights run 133-145g, and each will be available later this fall for $99 each.
As an even more obscure ‘standard,’ T47 is struggling to gain acceptance, but that hasn’t stopped Wheels Manufacturing and others from offering bottom brackets for it. Their new T47-BB will be available in internal or external bearing designs and like the 386EVO BB above, will be offered in SRAM (24/22mm) or Shimano (24mm) specific fits. To be sold with angular contact bearings only, pricing is still TBD but you can expect to see these in about 2-3 weeks.