I really don't remember exactly. I think it was 1.25", but it might have been 1.5". I picked up a couple of bicycle inner tubes of various widths from the local bike shop. Of course they were punctured and going to be tossed anyway. I called the shop up beforehand and asked them to hold a few different sized ones for me and they did. There are a few uses for old inner tubes. BTW, someone suggested using alcohol as a lubricant to slide the piece of inner tube over the grip. I just kept working it on and tugged and tugged. Someone else suggested removing the white powder before sliding it on. They both might be good suggestions, but they came too late for me.