Because solid foam-filled tires suck. Something anybody who’s ridden on one will know.
The tire needs air inside to do its job properly. This article says it doesn’t affect performance and handling, but it absolutely does, and you can feel it. (It also increases weight a bit.) Airless tires always feel a little mushy and wobbly to ride on, and they don’t rebound as quickly, which means you don’t get energy back out of them when they go back into shape after deforming against the ground, which means they take more effort to pedal and are less efficient.
Better to carry a spare tube and a changing/inflating kit than to have both tires stuffed with these.
I will say though: I have tubed tire liners on one of my e-bikes with low PSI fat tires, and they’re actually kinda great.
Mine are Tannus Armour though, and air is still used in the tubes.
This isn’t discussing solid foam-filled tires though…
These are not meant to be airless tires though. The foam core is basically an emergency run flat system. It also lets you run a much lower pressure than you otherwise could which is kind of game changing for some applications.
I got a set at the end of last year and used them on my aluminum commuter bike until I switched over to the winter setup. I really liked that I could run like 35 PSI on gravel tires and still be able to hop curbs and generally do urban cycling without worrying about rim damage as much.
“Might save your life” sounds rather over dramatic
It may even save your wallet, and those expensive carbon rims!
I happen to use the Vittoria’s Air-Liner insert for my rear tires. My use case is bikepacking, and mountain biking (hard tail). One of the first things I noticed was the additional side wall support - I haven’t burped a tire in a long while. They have probably also saved my rims on a number of occasions when I’ve hit a rock or root edge when sending it. I think it’s worth the piece of mind.Also, they aren’t just pool noodles, they are made a bit different for use with tire sealant. You may also need to change out your tire stem, for one that will accommodate air passage/interference with the insert.
