Dual bearing X-idler seat extension for the German RepRap x400

The original German RepRap x400 comes with 3D printed sintered plastic X and Y carriages. The X direction idler pulley sits in the Y-carriage in a cantilever fashion attached to a 608zz bearing using a shoulder bolt. The tension on the X-belt causes a deflection of the idler's axis, therefore grinding into the belt. This must be an oversight in the original otherwise good overall design of this 3D printer. There is also nothing stopping the bearing from sliding out of the 10mm thick seat other t