I think it will depend on what you are going to carry. I built my built my sled last year and mounted the risers more toward the front of the skis. At first I thought I put them too far forward. But after adding an auger rack on the back I still have plenty of ski hanging off the back. If I ever got a bigger sled, I would have to move my auger rack toward the back of the skis to allow the bigger sled rest on my cross bars of the smitty.
