Someone replacing a worn or gritty bottom bracket on a bike with a 73 mm threaded shell and square-taper cranks.
This is a sealed cartridge bottom bracket for frames with a threaded 73 mm shell. The bearings are sealed inside the unit, so it goes in and comes out as one piece, and a waterproof seal helps keep water and grit away from them.
The cups are alloy, the sheath is aluminium and the boron steel axle is 127.5 mm long with square-taper ends, so it suits square-taper cranks that call for that length. Before ordering, check the shell width and thread on your frame and the axle length your crankset asks for.
Sealed cartridge
One sealed unit with the bearings built in, so there are no loose balls to set up.
Alloy cups
Alloy cups and an aluminium sheath, made for a 73 mm wide threaded shell.
Waterproof seal
A waterproof seal helps keep water and grit out of the bearings.
127.5 mm axle
A boron steel axle with square-taper ends, for cranks that call for a 127.5 mm axle.
Fit
Build
Great for
Maybe not for
Check three things before ordering: the shell is threaded and 73 mm wide, your cranks are square taper, and 127.5 mm is the axle length your crankset asks for. If you are not sure, measure the old bottom bracket axle or check the crank maker's guide.
Match the axle to the crank
Axle length sets how far the cranks and chainrings sit from the frame. Too long or too short and the chain lines up badly, so go by what your crankset maker recommends for your frame.
