Effetto Mariposa has a new thin, lightweight EVA foam anti-pinch tire insert. Stick the Tyreinvader into large-volume gravel & mountain bike tires to protect against flats, while maintaining all of the performance benefits of your fancy tubeless setup.

Effetto Mariposa Tyreinvader anti-pinch tubeless tire liner

A number of anti-pinch tire inserts have popped into our tubeless tires over the course of the last year or so. All promise to allow us to run lower tire pressure for more grip, while still preventing the (increasingly rare) pinch flat. Plus, also protecting our precious carbon (or even light alloy) rims from unexpected rock strikes. So what do Effetto Mariposa’s new Tyreinvaders do differently?

By using a thin, perforated flat design that floats in the middle of the tire’s air volume, the high-density Tyreinvader claims to only impact your ride feel during that unexpected pinch or rock strike. Since it takes up less volume within the tire, it minimizes any noticeable impact on the feel of comfort or rolling resistance associated with compression of the air or foam liner inside the tire.

Effetto Mariposa Tyreinvader anti-pinch flat EVA foam tubeless tire liner insert

The closed cell EVA foam, like used to absorb shock in athletic shoes, won’t absorb any of the sealant inside of a tubeless tire setup. Mariposa still says to put an extra 30ml of sealant into a tubeless tire, simply because the Invader greatly increases the surface are inside the tire and will be wet with the sealant floating around anyway.

Mariposa Tyreinvader liner Tech Details

Effetto Mariposa Tyreinvader anti-pinch flat EVA foam tubeless tire liner insert

Mariposa claims the Tyreinvader insert weighs at least 50% less than competing liners. That amounts to claimed 53g per 700c/29″ wheel for each 40mm liner, 68g for 50mm, 80g for 55mm & 92g for 60mm (down from as much as 250g per wheel for many heavier alternatives on the MTB market). A few hundred grams isn’t a huge deal in many cases, but keeping excess rotating weight out of your tires will keep pedaling from feeling slow & handling from becoming sluggish.

Effetto Mariposa Tyreinvader anti-pinch flat EVA foam tubeless tire liner insert

The Tyreinvader comes in four sizes for use inside of tires from 42-54mm for gravel bikes and 54-80mm wide for mountain bikes. Mariposa says their liners are easy to install, after first trimming them to length (for 27.5 or 29″ installs), then zip-tying the liner into a complete loop that will float in the center of the tire’s shape until an impact.

Effetto Mariposa Tyreinvader anti-pinch flat EVA foam tubeless tire liner insert

The made-in-Italy Tyreinvader sells from $50/40€ a pair in the smallest width that will work with 26″, 27.5 & 29″ tires. 50mm sets sell for $70, 55mm for $85 & 60mm pairs for $95. All will be available direct from Effetto Mariposa in January 2019, and in US bike shops via QBP distribution.



    • Rodrigo Diaz on

      Hm. I actually like their sealant, especially for road/gravel tires with their slightly higher pressure (40 psi and up). I don’t like the lifetime in the tires, though. What is your preferred sealant and what do you use it for? Not much luck with the Finish Line sealant, briefly tested Muc-Off but ran out of CX season.

  1. Big Randy on

    Same weight and price as Huck Norris that I am currently using. Can say 100% that inserts like these work and have saved my tire a few times.

  2. John on

    Although the difference is probably minimal I am slightly annoyed by the letters in the foam. Just having round/oval holes in there would reduce the weight and surface area which would require less sealant.


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