Buy a Bike Pro first, then strap lightly from the inside of the handlebars in frt and floorboard supports in the rear. All your doing is making it steady with the straps in case of a impact (accident) the Bikepro holds it vertical, the straps are just insurance. I have no problems this way, I do use "rabbit fur" on the soft straps over the bars. Bike Pro sells a secure strap that goes over the frt wheel, it will not work on our bikes, it hits the rotors.
This is my first trailer since dirt bike days 30 years ago (and they weren't road worthy). Have towed about 2500 miles in last year and bike stays very steady and secure. Bike Pro is one of the best "gimicks" that I have ever bought. Loading and tying down are safer as well as easier.
By the way, I have a 6 x 12 Pace Legacy Gold with fully lined interior, helment rack (dual), electric brakes, HD drop gate, Alum wheels, Mannington Supreme Black/White flooring ($35/yard) and polished treadplate runner for bike, Screwless sides, white with gold graphics. It is for sale if anyone is interested.