Riders replacing a worn bottom bracket, or building up a frame, with a 77 mm asymmetric T47 shell and a SRAM DUB road crankset.
The SRAM DUB T47 77-A bottom bracket is made for a specific frame standard: a T47 threaded shell that is 77 mm wide and asymmetric. T47 frames use a big 47 mm thread, so the bearings can sit in the shell and you still get the creak-free, easy-service benefits of a threaded bottom bracket.
It takes any SRAM DUB road crankset. The same part works for Road and Road-Wide cranks: Road uses a single 3 mm spacer on the drive side, while Road-Wide uses 2.5 mm on the left and 5.5 mm on the right. Bearings are sealed cartridge units in black aluminium cups.
T47 comes in 68, 77 and 85.5 mm widths and they are not interchangeable, so check your frame spec before ordering. If you are not sure what your bike takes, bring it in and we will measure the shell.
T47 77-A fit
Threads into 77 mm asymmetric T47 shells.
Road and Road-Wide
One part number, different spacer layouts for each crank type.
DUB spindle
Takes any SRAM DUB road crankset.
Threaded and serviceable
Installs and removes with a 16-notch external BB tool.
Fit
Construction
Installation
DUB
SRAM's 28.99 mm spindle standard. One spindle size works across every DUB bottom bracket, so the crank stays the same and only the bottom bracket changes to suit the frame.
Sealed cartridge bearings
Sealed bearings pressed into the cups keep water and grit out and are replaced with the bottom bracket when they wear.
Great for
Maybe not for
Check your frame is T47 77 mm asymmetric before ordering. SRAM's spacer chart: Road crank = 3 mm outer right only. Road-Wide crank = 2.5 mm outer left and 5.5 mm outer right.
Get the spacers right
Road and Road-Wide DUB cranks sit at different chainlines, so the spacer layout is what makes this one part fit both. Set the spacers to SRAM's chart for your crank before torquing to 50 N·m, and grease the threads so it comes out easily next time.
Check the shell first
T47 shells come in three widths. Measure across the shell faces or check your frame maker's spec. A bottom bracket for the wrong width will not set the bearings correctly, even if it threads in.
SRAM is an American component maker founded in Chicago in 1987, starting out with its Grip Shift twist shifter.
Today it makes drivetrains, brakes and more for road, gravel and mountain bikes, and its family includes RockShox, Zipp and Quarq.
