I'll weigh in on this. Not a motorcycle trailer, but one I built from scratch as I needed it to be light. My tow vehicle is the hand-me-down, then hand-me-back-up sedan I let my kids have all through college so it's high mileage, worn out and can't tow a lot (Chevy Lumina sedan). Car (scratch build book Locost) is a BEC, weighs 1,100 lbs and the trailer is about 325 lbs. I looked at plans on the internet and followed a guy who did a Europa trailer somewhat, but varied from that in places. Search Europa trailer and you should find them.
Bought the axle locally same for steel. Tires/wheels rated at 1,100 lbs each and fenders from Amazon. Bought a winch online and put it all together. Painted with POR15. Registering it in MD was an enormous pain. Three times to the MVA, but in the end it's registered and I have hauled my car on it successfully several times. Attaching a picture of my first track day with the car.