It hasn't been a problem for me yet as my first shelterw/ built in sled is very new and haven't used it much.....but a friend said that his sled nearly wore out because of having to pull it over some rough areas,.. he said he fixed the problem by screwing a dowel that he planed one side, to the edge of the sled and attached one/two of those rolled up kids plastic sliders,..cheap at big toy stores,..they are very tough and take all the stress,/scrapes ..thought I would pass that along to anyone that is conserned about wearing theirs out...I imagine tough and costly to fix once its worn through...