BromptonBrompton ModTroubleshooting Maintaining the 68mm BB standard with the road bike crank on the Brompton by Petrelli September 27, 2018 by Petrelli September 27, 2018 The Brompton bottom bracket follows the BSA threaded standard, the common shell width on the BB is 68mm. Owning to the fold-ability design, the… Read more 0 FacebookTwitterPinterestEmail