Diagram & Table below from Orbea Blue Papers
Even after the Main Pivot Axle had been tightened this was going to keep wearing so I decided to reinforce the area. As there was a raised shoulder of carbon composite around the threaded axle hole it was possible to remove the shoulder by careful filing and replace it with a stainless steel shim washer (15 x 22 x 1mm) glued in to place with epoxy. The filing was done with the main pivot axle removed and rear triangle still attached to the frame, though it would be easier to work on with it removed completely.
Photo Below: wear to the carbon composite chainstay caused by the inner race of the driveside bearing.
As the inner race of the bearing is clamped between a shoulder on the main axle and the chainstay, with time and the forces from riding the bearing has worn the chainstay. (I think the newer Occam model has an aluminium chainstay)
The fit of the bearings on the axle and axle tightness should be carefully checked on any bike using this system.
To keep the filed face parallel with the bearing (perpendicular to the main axle) the axle was used as a guide by threading it in from the outside of the chainstay and comparing the filing progress with the end of the axle.
Photo Below: The carbon composite chainstay with shoulder filed off
The stainless steel shim washer was thoroughly scuffed, spirit wiped then glued in place with a 2 part epoxy adhesive (Araldite Standard) it was held in place using the shoulder on the axle taking extreme! care to avoid getting adhesive on the threads.
Photo Below: The chainstay with shim washer glued on
