Every millimetre counts!
There are some tricks necessary to place an 11spd cassette, as the almost 2mm, for which an additional sprocket is necessary, have to come from somewhere. Unfortunately a little longer freewheel body is in that case not sufficient, as the chain on the smallest sprocket could collide with the frame. Therefore our hubs get built a millimeter larger. That should not affect the assembly into the frame. The rim is placed 0,5mm excentric after a rebuild from a 10spd into 11spd freewheel. Normally that does not disturb. There is an exception with a very limited rear tire freedom. Here it is useful to center the rim again. This is easily possible with our wheels.