My friends all have fancy travel bags including the Chain Reaction oe. It comes with these awesome frame spacers which look like  great idea. You put them in place of your wheel and pop the thru axle back in and it stops the frame or fork form getting crushed. Given that 2 of my mates have lost bikes in boxes to this failure, I wondered if anyone makes them? Essentially aluminium tubes that drop right in to the wheel space. They have them different sizes depending on your frame boost 142 135 etc.

No one?

Get a bit of plastic tubing from B&Q and make your own, takes about 2 minutes.

These from Birzman.

https://www.evanscycles.com/birzman-protective-fork-front-spacer-EV189318

https://www.evanscycles.com/birzman-protective-rear-chain-spacer-with-chain-keeper-EV189309

The birzman ones are for road bikes, not 110 boost front and 142 rear..  Bum..

tbh i reckon the best thing to use a nice block of a wood and drill a hole in it and use your axles. Won’t damage your frame and will be nice and wide and stable. You can also tie the rear mech to it with some string nicely tucked up into the space between the dropouts.

As above with hard plastic tubing.

Or or what I did when I last sold a frame. Cut a length of M10 threaded stuffing longer than you need, fit in the dropout with 4 x M10 nuts, two on the inside against the frame, two on the outside of the dropout. Nip the nuts up.

As mentioned above – I use 15mm plastic water pipe cut to desired spacing works with with 12 and 15mm through axles.

Yeah my mates have used bits of wood etc before and done job fine.