While learning about hard hats, I poked around in a heavy equipment user subReddit where participants traded tips about finding comfortable hard hats. This would be a goldmine of info for an industrial designer trying to improve the UX of hard hats.

A number of the posters recommended an aftermarket product called the ChukBand, by ChukStar Leather Goods:

These pieces of elk leather render even the cheap plastic suspension systems of a variety of helmets more comfortable. They're padded and you wrap them around both the front and rear suspension elements.

You choose a model based on your make of hard hat. Some ChukBands feature cutouts that correspond with existing hard hat tabs; others snap shut with YKK fasteners. Still others leave access to the ratcheting knob that tightens/loosens the suspension's fit.

Why elk leather? "Elk leather won't stiffen or get crusty like other hides," ChukStar says.

They come in a variety of colors.

One downside for the chemically sensitive is that ChukBands are chromium-tanned.

These run $40 to $50 for a set of two (you need one for both front and rear).

I love products like these; this was definitely invented by a hard hat wearer.