I have had problem with low angle ramps like Coal Harbour. I found my keel would drag on the back cross member if the boat cleared and I tried to pull forward then back again. My two center bunks stop about 4 feet short of the rear crossmamber while the two outside bunks go all the way back. I installed a 12" wide roller on the back crossmember and it seems to work much better. My axles don't hit, but if they did, I think I would rip a piece of PVC pipe length wise and clamp with a couple s/s clamps. All my forward crossmambers have pads I got from trailer manufacture.