The Effetto Mariposa Tyreinvader provides great protection to rims from impacts when running low pressures. It's easy to install and doesn't soak up sealant, though there are better options if you're looking for bead retention too.
Tyre inserts are slowly making their way into increasingly narrow tyres, and while the Tyreinvader isn't an option for road tyres – the narrowest version is for 35mm tyres – it is a great way to add some rim impact protection in a gravel, mountain bike or cyclocross setup.
What you're getting in the kit are two long strips of high-density EVA foam. They're long enough for 700c wheels and come with cut lines should you be running 650b wheels. The strips have cutouts along their full lengths to allow sealant to easily pass through, and some are in the shape of the old 70s Space Invaders game. Hence the Tyreinvader name, presumably (and maybe the lack of a space in the name because it's not space invaders, it's tyres... I may be overthinking this).
Installation is really simple. In fact, compared to other inserts I've installed, these are easy as they sit within the body of the tyre instead of (like Vittoria's Air Liners) down in the rim well. Down there they can make installing the final section of tyre bead very challenging.
I might be teaching you to suck eggs here, but with one side of the tyre on the rim, you can get the Tyreinvader ready by using the included zip ties to secure the two loose ends together. Clip the excess off with some scissors and then put the Invader into the tyre, making sure the gap for the valve is roughly in place – you don't want to disrupt the airflow.
You then simply put the second side of the bead onto the rim and push the sealant through the valve.
With that done I got on with reviewing the ride. The Tyreinvader is wider than the rim, offering coverage for rock strikes. I generally seem able to find a few on each ride and it wasn't long before I hit a good one. With these installed there wasn't that horrible sound on impact - you know the one. It sounds like the wheel has surely broken into many pieces.
Whether the inserts would offer much protection from absolutely massive hits, I'm not sure, but it is nice to feel the rim is at least a little protected from the regular impacts of general gravel riding. Really though, for 99% of the time, I couldn't tell I was riding them.
At £50 this is one of the cheaper ways to protect your rims. The Vittoria Air-Liner Tyre Insert Kit I mentioned is £89.99, though the kit includes an installation tool, valves and sealant. CushCore's Gravel.CX offering is over triple the price at £160, which makes the Tyreinvaders seem like an absolute bargain.
On the other hand, the designs that sit lower also offer some bead retention benefits by physically holding the tyre in place, and you're not getting that here. I'll admit that's only really a consideration when running excessively low pressures during a muddy cyclocross race, though.
These are easy to install, effective once they're in and just get on with the job pretty much invisibly. The price is attractive too.
Good rim protection from an easy to install and affordable insert