Just tagging along here to say I'm also wondering what alternatives to indoor/outdoor carpet folks have had success with.  I just put together my Trailex and I'm not happy with the bunks--one is pretty warped, and the carpet was poorly attached--a bunch of loose staples.

I'm planning to make new bunks out of treated 2x6 stock I have and figure I might want something better than cheap carpet that will hold grit.  Did a quick search and there are lots of products out there, some quite expensive (e.g., Gatorbak).  

Any tips?

I wasn't impressed with the quality of carpeting on the bunks that came with my SUT-220-S I bought to haul my Waterlust expedition canoe to launch sites either.

Or the bunks themselves for that matter, given the shape of my hull compared to how the supplied bunks would have (not) supported it.

So I used the supplied aluminum bunk hardware bits to support a custom bunk I contrived from treated 2x dimensional stock (carefully designed to support the hull under two of its frames as well as along the flat bottom between those frames) that I then covered in bunk carpet sourced from E-Trailer.com.

Stapled on with monel or stainless steel staples that I made certain were set deeply into the carpet, I've had no 'sticking' issues in the two shortish seasons since first launch in August of 2021. Over winter the trailer sits outside, uncovered next to my garage; the carpet shows no signs of degradation... so far.

   I owned a very heavy trailer sailor that had five full length bunks.  I found that occasionally putting a bit of dish soap on the bunk carpet significantly reduced the friction and made the boat much easier to retrieve.

   I looked up the bunk carpet. I am assuming that it is not the same as the original carpet on the trailex trailers. It seems a bit pricy but far less expensive than a chiropractor. I'll give it a try. 

Dish soap sounds reasonable for a quick fix once the boat is not stored on the trailer. 

Thanks for the ideas.