Wednesday, August 1, 2018

Something’s following you

I dislike hitch-mounted racks (HMR). I don’t care that other people use them, but from a personal, philosophical, how-I-hope-to-live-my-life perspective, getting an HMR would be a sign I’m hauling around too much physical and maybe emotional baggage.

From the perspective of the little I understand about physics and engineering, I wouldn’t want one hanging from the back of the Rolling Steel Tent. It seems like attaching a wiggle machine to one’s rig.

How is having a few hundred pounds attached by a single point a good idea? The thing’s a pendulum, diving board and teeter-totter combined.

Sure, it’s fine sitting still, but once under way, various forces want to flop it around. Every turn and bump of the vehicle gets transmitted to the HMR. The HMR reacts (in that Newtonian equal-and-opposite way) and transmits its motions back to the vehicle—all through that one point where the HMR meets the hitch.

Mounting rack to the vehicle at two points could eliminate roll and yaw. Attaching it at three triangulated points could eliminate pitch too. But the buying public loves the idea of easy installation and removal, so we have HMRs.

HMRs don’t necessarily flop around in a way you can actually see, but the forces are still in action, still causing stresses, still causing wear and tear on itself, the vehicle and you.

3 comments:

  1. The only reason I would consider a hitch mounted rack is if my vehicle was too small to hold, without disassembly, my TravelScoot. Which weighs 34 pounds. Which may be less than the rack. I could get all the rest of my daily needs met inside even the smallest van.

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  2. Crossing dips in the road surface is another hazard.

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  3. On a bigger scale;Thank God for Boeing.

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