Loading 5 long tracks in a 7x29 is easy. Drive all in from front to back, first sled driven in needs to be loaded opposite of the v door so you can drive the last one in. I hauled 5 long track sleds (155, 153, 154, 154, 154) in it every weekend with no problems. See the first picture.
With that trailer I learned the hard way that you get what you pay for and it didn't last a year of normal use, even being custom ordered with all the premium options. I do 4-5 trips to and from MN to WY, MT, ID each year.
I now own a 2016 Aluma 8.5x28 (24+4v) lowboy car hauler, twice the price at $18k, but 10x the trailer and worth every penny. I will never go back to a 7'. This trailer while being heavier pulls so much better, doesn't sway in the wind, and while being a foot shorter total, has tons more room inside. Definatley the 8.5' lowboy car hauler is the way to go. I can very easily get 6 long track sleds inside.
Having the sleds side by side is extremely easy to get around, I would typically cram 4-5 long track sleds into the 7' and what a pain to get around and tie down..
Here are some photos of mine. It is a 2016 Aluma 8.5' x 24' with a 4' v-front. 100% all aluminum, no wood. All aluminum floor and ramps. 5200# axles.
YOU GET WHAT YOU PAY FOR WITH TRAILERS....