I had already checked the parts list I got from Alroh last week but all it contained was a part number. As suggested I then gave them a call. The description for the pulley being 2x1Ax1/2 (I think) suggested a 2 inch pulley. A quick stop at Alroh on the way home to look at the part showed it was a 63mm pulley. I measured the current one when I got home and reckon it is 3". Now I just need to decide 2" or 2.5" as the replacement. They also advised some slip was ok but you would run without slip most of the time.
