I really don't see how that beer dolly with no suspension keeps the wheels on the ground at anything over 15 or 20 MPH. What do the tar strips do to it at the speeds you're claiming?
And what does all that jostling around do to your engine? I know it's a Honda clone, but still . . . I guess it uses "splash lubrication"!
If you're getting a high speed miss it's probably the low oil shutdown in intermittent mode.
Ted
It Was a Handtruck, but now it's modded up so much, it's a trailer of it's own. It's almost like the rear-end of a small go-kart that attaches to the rear of the bike.
Works fine on bumps. The engine doesn't shut down on me because I always check my oil level, and doesn't have trouble on hard turns either. If I'm on a REALLY bumpy road, like the dirtroad/pothole-asphault road for 1.5 miles exiting my neighborhood, I pedal most of the way on the huge bumps, but still can go faster than the cars on avg, because I dodge potholes @ 25+mph, while the cars are still going 10-15mph. (the road is that bad)
On the main road or highway shoulder, it's smooth, because of the angle of the trailer, giving it throttle pushes the wheels harder into the pavement for more grip, and I ride a full suspension bike, so small bumps are tolerable. I make sure to avoid bumps as much as possible because the trailer doesn't take the bumps as well as the bike, but if I hit any large bumps, I can let off the throttle for a moment to retain control.
It cruises well at 35mph and does over 40mph easily, and as long as I drive it on smooth road, or operate it at the right speed for the terrain, it's a blast to have on the bike. Also having solid-poly Marathon Flat-Free tires on the trailer takes my worries away about tires, and reduced my bounce on bumps significantly over regular air tires.
I just got a new helmet, and car horn, and now I'm setting up the rest of the electrical on the bike. I'll feel very safe riding it, you'd be amazed how well this thing rides. The trailer follows nicely behind the bike.