Shimano Deore XT Hollowtech II Bottom Bracket

The standard bottom bracket for Shimano XT Hollowtech II cranksets with BSA threading and washers for fitting chain guides. The new BSA bottom brackets have narrower races, so the TLFC37 tool is required for installation.

BSA threaded bottom bracket shells

The BSA bottom bracket shells have a width of 68–73 mm and a 1.370 × 24 TPI thread, with an outer diameter of 33.6–33.9 mm, into which the bearing cups are screwed. Both bearing cups are screwed in the direction of travel. The different shell widths are accommodated using the washers included in the delivery.

Shimano Hollowtech II 24 mm MTB crank axle:

The Shimano Hollowtech II crankset system has a solid 24 mm axle. The MTB cranksets have a 120 mm long crankset axle. The DH Saint and Zee cranks for 83 and 100 mm installation widths have longer axles and will only fit in frames with correspondingly wider bottom bracket shells. The respective bottom brackets are compatible with one another.

Shimano Deore XT BB-MT801 Bottom Bracket Technical Specifications:

• Aluminium threaded cup bearings
• BSA thread, 34 mm x 1.37 TPI
• Installation width 68–73 mm
• Thoroughly sealed
• Includes four washers: 2 x 2.5 mm, 1 x 1.7 mm, 1 x 0.7 mm for adjustment to 68/73 mm bottom bracket shells when fitting chain guards

All Shimano Hollowtech II bottom brackets are compatible with all Hollowtech II MTB cranksets. You can also fit an SLX crankset with an XTR bottom bracket or vice versa. Adjustable to 68 and 73 mm bottom bracket shells using the spacer rings. Also compatible with E-type derailleurs and chain guides. Please note that to install the bottom bracket, the frame thread must be cleanly re-tapped and the sides of the frame housing must be planed. Otherwise, the bottom bracket will have a short service life.

Herstellerinformation: SHIMANO INC., 3-77 Oimatsu-cho, Sakai-ku, Sakai-shi, Osaka 590-8577, Japan, www.shimano.com | EU contact: Shimano Europe BV, High Tech Campus 92, 5656 AG Eindhoven, The Netherlands, www.shimano.com