THM-Carbones BSA 68-73 mm MTB bottom bracket compatible with Clavicula XC and M3 cranks with 30 mm axle diameter. This axle diameter in combination with the external bearings increase the stiffness of the cranks and extend the service life of the bearings. BB shells are made of aluminum CNC machined with BSA long threads (compatible with 68 mm or 73 mm BSA threaded frames) and then black anodized, bearings are high quality steel ones and also 3 aluminum compensating spacers are provided with the BB. Only 77 gr. weight (80 gr. included the spacers). Installation require THM BB tool.