Turn the belt inside out you have got it with grooves outside.The belt on my trusty Axminster AWSBS finally gave up the ghost after about 15 years service.
I've got a replacement from Axminster but have two questions. The pulley wheels are grooved and yet the belt is notched. Kind of expected a grooved belt but what do I know !
But the real $64000 question is how on earth do you get it over that bottom wheel ? There's a circlip - now removed - thought it would just pull off. There are those three Philips/Pozidrive bolts. Which are seized solid. I could undo the four bolts on the other side of the panel that hold the shaft in place but I'm told that if I do that ....well, not a good idea.
Any suggestions ?
Take off circling pulls slides off.