After last year's fiasco of ruining 6 tubes trying to install the orange conti trainer tire on my road bike, I have decided to take a different approach this year. My thought was to just use an old slightly worn tire and just mount it with no tubes and use it on the trainer without any inflation. It should still provide resistance, and fits tight enough on the rim that it should not randomly roll off.

Is this a bad idea? If so, why?

you need to fill the tire with something, to hold the rim off the trainer roller .
Occupied NL WW 1?2?, they are said to have filled their bike tires with straw from the fields ..

there are 'captive air' tires , essentially a foam molded tire to pry on the rim, it has some bead cords molded in,
to keep it on.. being on a trainer the chance of rolling it off the rim is nil.

I have 1 a 27" one, a bout like a 1.25" width , if you want it, PM and we can talk terms.

LeMond has a trainer that has a cassette on it,[ it, at some cost,] replaces the wheel itself.
the resistance is fan blades , so not quiet, I assume..

I have a mag trainer with an adjustable clutch that lets me set the position of the roller, So i can set it so i have resistance without the rim touching

Why not just mount the old tire with a normal tube? I ride the trainer in the winter with an old tire and don't notice any wear.

Just learn how to install a tire properly or have your LBS do it or get a tire that mounts easily like a foldable tire. Just don't run without air.

yes, bad
Same reason you dont ride your bike outdoors with no air


Rim damage
they don't like force to be focused right on the edges
inner tube and tire distribute force evenly, keeps the dents out

I don't know that it is actually going to damage anything. I doubt it, except for the tire itself. Kind of a solution looking for a problem, though.

Whyt not just use a regular tire and tube?

So the hidden detail is you have a trainer that has the roller on the edge of the rim
where the braked grab?