Like most other XTX owners I've had to replace the cush rubbers in the rear hub way too often.
After the third set of rubbers I took a closer look at the hub design.
Looking at the bearing boss on the wheel I saw evidence of contact with the sprocket carrier pocket, this should not occur, as there is clearance between the two.
The solitary bearing in the carrier is not up to supporting the load from the drive chain and twists under load and makes contact with the bearing boss.
(your hub will probably show scarring from this contact like mine did in 2nd picture).
This twisting action chews the rubbers to pieces inside the hub.
My solution was to bore out the pocket in the sprocket carrier and press in and loctite a machined plastic bush (UHMWPE) with a clearance between the bearing boss and bush of about 0.2 mm ( just enough to allow the hub to rotate without binding), I then coated the bush / boss contact with grease and assembled (1st picture).
That was around 5000 km ago and the rubbers are looking good, there is still some wear as the rubber is crap but the rapid destruction has gone.

Attached Images

	DSCN0384 (704 x 528).jpg (88.2 KB, 134 views)
	DSCN0381 (704 x 528).jpg (72.4 KB, 131 views)