How to select the correct T47 bottom bracket

T47 bottom brackets are fairly new to all of us. We discussed some of the finer details of T47 in this post. Two advantages of the T47 system are that it can be used across a large spectrum of frames and with almost any crankset. Wheels Manufacturing currently offers T47 cups with either inboard bearings or outboard bearings. Both types of cups can accept 22/24mm GXP spindles, 24mm spindles from Shimano, FSA, RaceFace, etc., 29mm SRAM DUB, and 30mm diameter spindles. So how do you determine which T47 bottom bracket to use?

Start with the crankset to be installed in the bottom bracket. Choose the bearings that work with the spindle (30mm, 29mm, 24mm or 22/24mm). On our T47 bottom bracket page, you can filter the BBs shown by Crank Spindle Diameter to narrow down your choices.

With any bottom bracket, the wider the bearing stance you have, the more durability you will get out of the bearings. Select BB cups that position the bearings on the spindle as close to the crank arms as possible. Crank spindles come in a number of different lengths, so taking proper measurements will point you in the right direction. The most accurate measurement is going to be from the inside face of one crankarm to the inside face of the other with both arms attached to the spindle. This is the usable space on the spindle that the frame plus bottom bracket can fit into.

The crank shown in the photo above has an available spindle length of 69mm. If you are installing this in a 68mm wide shell, you would then use the Inboard bearing cups (T47-BB-30MM), which have a frame + BB overall width of 68mm. A complete list of our overall bottom bracket widths can be found HERE. For T47, the following chart shows the overall width of the BB in a T47 frame:

As with any bottom bracket, frame and crankset combination, taking proper measurements of all the parts involved will help to sort out what will fit and what will not.