Gusset EXT24 BB Gusset offer a BB for most hardcore MTB and BMX uses, and now have an “External” type to fi t most 24mm axle type cranksets (including our own TAF24 cranks) Forged and CNC machined alloy cups. High quality cartridge bearings or Ceramic option. Lightweight plastic central dirt seal. Fits with most “24mm External” type cranksets. Weight 106g Black anodised. Fits 68 and 73mm frames.