stones etc getting dragged through the wheel cavity

[Uras]

I was researching tires and came across a comment on a particular wheel and tire fit. I had been thinking about how to avoid all those little stones etc getting dragged through the wheel cavity - out of these two things I've had an awesome idea. Where the tire enters the wheel cavity, at the rear of the euc - that should be the narrowest point. After this point the space in the wheel cavity should be slightly bigger. Ideally it would be good if it was gradually larger all the way to where the tire exits the cavity (front of the euc). This way if a small stone gets past that intial narrow gap between tire and euc at the rear of the euc, it will easily continue through the cavity unhindered until it exits.

The variation in space of the wheel cavity only needs to be 5mm or so from start to finish. Of course stones are irregularly shaped and may still get dragged around - but I think this design should alleviate a lot of that.

It's something I encounter on my rides all the time. It has really bothered me, although I know that the inside of the wheel cavity must be pretty well scored by now. I can imagine a hole getting punched through there eventually.

[alcatraz]

I thought this was a problem until I saw that on my wheels the wheel cavity isn't "tire shaped". It's more resembling a square cutout with lots of space in the corners. So even if something does get wedged in the middle where it's tight, there's space for it to deflect sideways and exit. Also, wearing in a tire and centering it perfectly on the rim, can do wonders with clearance. 

I can't speak for all wheels though.

[Tawpie]

Way back in the day when racing road bicycles used sew up (tubular) tires and the people that invented cell phones were in high school, bikers would put a little brush on the front of the tire that would barely skim the surface to loosen any debris before the tire came back onto the pavement... those things were too easy to puncture and a flake of broken glass was enough to ruin your day.

You could try something similar at the rear of the wheel though, something to skim off or at least partially dislodge stones. Might not work because in the case of sew ups, you were worried about tiny things whereas the things that get caught in the tread are quite a bit bigger.