#!markdown
Its an ~4mm smaller outside diameter, so if Shimano used the same architecture
in building the new MT800 BBs as the older gen HTII BBs the bearings would
have a smaller OD and the same ID so a smaller sized bearing in general.
I haven't pulled one apart, but from what Shimano is saying re. improved
sealing it is likely constructed very differently from their past BBs, so that
in itself may not be an issue (they are claiming improved durability).
Feb. 25, 2016, 10:27 a.m. - DrewM
#!markdown Its an ~4mm smaller outside diameter, so if Shimano used the same architecture in building the new MT800 BBs as the older gen HTII BBs the bearings would have a smaller OD and the same ID so a smaller sized bearing in general. I haven't pulled one apart, but from what Shimano is saying re. improved sealing it is likely constructed very differently from their past BBs, so that in itself may not be an issue (they are claiming improved durability).