CeramicSpeed 61903 Standard Bearing - (6903) MFPN=TA2126B The binding release function is

The binding release function is thus more reliable and effectively counters unwanted early release

Top-Close clamp design

and for polishing the base after scraping and brushing

This gives you plenty of room to equip tires that fit in with the type of terrain you plan on riding on a given day

CeramicSpeed 61903 Standard Bearing - (6903) MFPN=TA2126B The binding release function isCeramicSpeed cartridge bearings are an upgrade option for any cycling discipline. These bearings provide extremely low friction improved power transfer and a service life that far exceeds traditional steel bearings. Grade 3 Silicon Nitride balls Hardened steel races Reinforced polymide cage and non contact seal to keep dirt and moisture out High resistance to poor lubrication Can be used for any cycling discipline Sold as each Hand built in Denmark