That’s the difference between a small trailer not meant for speed and one that is. My tandem axle hauler goes 80 no problem. As do other larger trailers. But the common small 4x8 utility trailers one 13” tires I wouldn’t.
I guess the exact speed isn’t as important as the fact I don’t want a trailer that limits me to 55 on the interstate. Plenty of trailers can be towed at highway speeds, that’s what I am looking for.
Thank you for your explanation. I have 5 trailers, 2 are for my motorcycle, roughly about 3x4/5 foot, 13 inch wheels, I could tow them at 80, I don't. At times, they have both hit 70 but 65 is a sweet spot. 2 other trailers are dual axel boat trailers, 16 and 24 footers, they have gone a bit over 70 but again, the sweet spot is around 65. My 4x8 is a single axel on 15 inch truck tires. I keep it under 70 mph, generally between 60 to 65. My travel trailer is a dual axel, it actually likes 70 mph. The 13 inch wheels run trailer tires, the 24 ft. and the TT run truck tires, the 15 ft. runs LT tires.
What's all that mean? Not much really.
Not all states restrict trailer speeds, when they do, the speed limits apply to trailers seem to be set by weight limits, from what I've seen. Tractor trailer rigs may have different limits and are designed for higher speeds than your utility/camper type. A dual or triple axel 34' travel trailer will be subject to the speed limits just like a 4x8 utility trailer, the fact that it might track well at 85 mph isn't the issue, it's illegal.
I'd say it may not matter how you design a small motorcycle trailer, single or even an unnecessary dual axel, you will be subject to the speed limit laws set for smaller trailers. Best is just comply and make life easier.
My 4x8, I'm sure could cruise at 85 mph, but I wouldn't do that, a tire blowout can happen due to several reasons, just because my tires are rated for that speed doesn't mean they can't blow out. I don't know anyone running "run flat" tires on a trailer, but I doubt a cop would care.
I'm saying, you're not going to "design" a go fast motorcycle trailer that will be be allowed legally to go faster than any other run of the mill stock trailer of it's size. No special width, length, height, wheel/tire size or axel rating will exempt you from speed limit requirements.
Yesterday, on I-44, on the way back from Ft. Wood, some icehole in a pickup pulling a dual axel flatbed about 20 feet long pulled on to the interstate from the ramp doing about 70 and whipped his trailer in the right lane, a tractor trailer had to swerve to let him in. I had to hit the breaks. He took off doing 80+. Later, I caught up with him, three tractor trailers had boxed him in running about 72. He slowed down to try and get away from them and they all slowed down. When traffic backed up in the passing lane it's like everyone knew what was going on, the tractor pulled ahead and pulled over, people passed, then that lead truck pulled back in the passing lane letting the second tractor pull up. The drivers had to be talking to each other, they moved like an orchestrated dance. After about 15 miles they cut him lose and he behaved himself.
Not directed at the OP, but;
The purpose of posting about that idiot is to say, just because you can drive 85 miles an hour doesn't mean you should, regardless of how entitled you might think you are, or how bad azz you think you are, others have to drive out there with you.