Compatibility of Schlumpf hub with QX frames and d’Brake
QX frame, Schlumpf hub and d’Brake is the setup I built. But before someone wants to build a similar setup here’s a little warning: QX frames and d’Brakes are not compatible to Schlumpf hubs, they have to be modified!
As shown below, Schlumpf hubs need an inner bearing shoulder of maximum 3.1mm width and 2mm height (=(42-38)/2).
The original bearing holders of the QX frames have a shoulder that is 5.5mm wide and 4.5mm high (diameter: 33mm). That means you have to grind off 2.5mm off the inner side of each bearing holder as well as 2.5mm off the shoulder. If you don’t want to grind off so much from the side, you can also grind off a little less ad make a bevel where the shoulder is. Also the d’Brake does not fit. The shoulder is already 2mm high but about 1mm too wide.
If you want to use the small blocks that are provided with the 2016 model of the hub for torque support, you can’t use them as supposed to with this frame. The gab between the two halfes of the bearing holder is wider than theese blocks which means, you would lose them. My solution is to grind a groove right in the middle of the inner shoulder of the upper bearing cap to fit the block. I only used one of the two blocks.
