We really like BB30. As a bottom bracket standard, it offers numerous advantages over the current external bearing bottom bracket and seemingly no disadvantages except that it is available on a limited (but growing) number of Pro level racing frames. For the rider on SRAM/Truvativ equipment, a BB30 frame could leave you with a compatibility problem if you already have one of their external bearing GXP style cranks. Leave it to Wheels Manufacturing to come up with a nicely executed solution. Their BB30 Adapter for Sram/Truvativ cranks makes the fitment of GXP road cranks to BB30 frames a simple affair.
The Wheels Manufacturing BB30 Adapter consists of two reducer sleeves turned down from solid blocks of Delrin. These adapters utilize a press fit into the BB30 bearings and, once in place, allow you to slide the SRAM/Truvativ crank spindle through just as you would in a standard GXP bottom bracket assembly. The Delrin supports the spindle perfectly and the resulting performance is exactly what you'd expect from your factory SRAM cranks -- no wiggles and no creaks.
The Wheels Manufacturing BB30 Adapter for Sram/Truvativ is compatible with all SRAM/Truvativ GXP road cranks designed for external bearing cups and having a 24mm/22mm spindle.