Shimano BB-UN300 Square Taper Bottom Bracket - 68x118mm D4 250mm in Length – Accommodates

250mm in Length – Accommodates bars up to 50cm

Extended inner plate enhances chain retention

Optimized 7000-series forged aluminum arms support the X-SYNC 2 chainring for complete chain control

but short enough not to experience twist or damage under moderate torque as experiences on longer tools

Shimano BB-UN300 Square Taper Bottom Bracket - 68x118mm D4 250mm in Length – AccommodatesThe quality and performance oriented Shimano BB UN300 cartridge bearing bottom bracket features a JIS square taper mount and is designed for frames with BSA thread and 68 mm shell width. A stabilizer ensures a constant chain line. Specifications Adapter: aluminum (left), aluminum steel (right) Axle: steel Mfr Claimed Weight TBC