SHIMANO BB-RS501 BSA HOLLOWTECH II BOTTOM BRACKET trek kids What this means is that

What this means is that the filter is able to trap particles less than one micron in size

Type: Built-In

Flat Mount +20mm version for dropbar set ups

Removes all chain oil and wax residue

SHIMANO BB-RS501 BSA HOLLOWTECH II BOTTOM BRACKET trek kids What this means is thatThe BB RS501 from Shimano is a high quality bottom bracket for frames to BSA standard with 68 mm housing width. Usable is the Shimano BB RS501I with BSA thread for Hollowtech II cranksets with 24 mm shaft. Specification Use: Road, Cyclocross, City, Gravel Model: BB RS501 BB Type: HOLLOWTECH II (24mm) Threaded: BSA Threaded BB shell width: 68mm Shell diameter: BSA (BC 1. 37) Mounting: screwed Compatibility TIAGRA FC 4700, FC 4703 SORA FC 3550, FC 3503,