If you want to become a climbing gym-supplying tycoon and fix this problem, invent a new connector for holds based on a carabiner's autolock. You could pop the hold into a pre-set receptacle and it could spring closed, and a special tool could go into the bolthole to release the spring lock and pop the hold off the wall. No more re-tightening + faster route setting, and based on existing technology. Would probably cost the same as this special bolt, but provides enough extra features that a gym might rationalize the price.

Nope! There's no way any climbing gym would rebuild its walls to be full of expensive proprietary nuts. If they cared, they could use loctite or lock washers.

It seems there's very little money in fixing spun holds.

Climbing gyms change their "routes" pretty frequently, so I don't think they would use locktite.

Why? Loctite Blue is meant to be disassembled and reassembled: http://www.loctiteproducts.com/p/t_lkr_blue/overview/Loctite...

Gyms clearly don't use loctite, but I think it's just because the problem doesn't warrant the slight increase in mess and hassle.

Ah, okay. I thought locktite was only a "mostly permanent" adhesive. Thanks for the info!

You get different grades of Loctite. Climbing walls don't get that much vibration but a thread-locking product would provide some reassurance.

The only solution to the problem which I would trust would be continuous maintenance and a design that doesn't rely on thread strength to maintain a joint.

Yes, all holds need testing but it's reduces the maintenance cost if the holds don't need tightening all the time, surely? Also if the expectation value for loosening is lower per unit time it means there is less likelihood (other values being constant) that the hold has loosened since testing, with the same testing regime that makes it safer so far as I can see.

Since the customers typically tighten loose holds themselves, I would guess that the maintenance cost is vanishingly small.

It's definitely safer than a plain nut, agreed, but is it noticeably safer than any of the other thread locking solutions out there?