🚲 Shimano BSA Bottom Bracket (BB-MT800) for SLX and Deore XT Review

on a 1998 Cannondale Super V mountain bike upgraded from square to this one. My bottom bracket was 68mm wide so I used the 2 supplied spacers on the drive side and one on the non-drive side for a perfect fit. A plastic adapter is included to use the Park 59.2 tension tool as the OD is 39mm not 41mm but I also upgraded everything on my bike. The crank upgrade included a proper bottom bracket tightening tool. I installed a Shimano FC-M7100 SLX crankset for 1x10 and it slides perfectly with this…

I just installed this bottom bracket on my bike with RaceFace Affect cranks so I can't comment on the performance. However, the setup was complicated by the bike industry's penchant for dumb standard changes. The new style cups on this bottom bracket are smaller in diameter than what is considered standard for BSA male cups, so they cannot accept standard tools. Shimano includes a plastic adapter, but it was disposable at best. I had to hammer the adapter into the Park BBT-19.2's cup with a…

If you read some of my reviews you might notice a fondness for older cycling tech. The XT bottom bracket in this test is based on newer technology that impressed me. Yes, I know these bearings have been around for a number of years, but up until recent bike purchases, all my bikes used square taper bottom brackets, which I felt was the end of all bottom bracket technology. Square bottom brackets are hefty pieces of steel and grease that can be seriously damaged. Hollow bottom brackets like the…