Strap length is kind of a personal preference thing. Once you have the sled dialed in fairly close, you can use straps to change ski pressure with minimal effect on the remaining adjustments. I would start with just the slightest bit of tension and then go from there. Also, might want to check the front spring. I also start will minimal tension there also. If you get to much spring tension, the thing will teeter-totter, which makes the steering a bit erratic when you let off on the gas. Usually if someone has got the straps tight as heck, they have the spring messed up too.