I suppose it's a dumb idea, but could a person cut up another tire, say like a Thickslick, and insert it 'inside' the outer
tire? It would have to be cut at one point and sized, but not that much different from a poly liner.
Something like that is common; there's a bunch of threads about tires, tubes, punctures, flats, walks-of-shame, etc., and variations on this are discussed in a few of them if you need details of other versions than mine.
Myself, I now use 16" moped tires and tubes on the rear 20" bike wheels of the trike, and they solved the puncture problem and actually cost less than bike tires that would've done the same kind of thing with technology rather than rubber thickness.
The front is a 26" wheel though, and I haven't tried to find a (19") MC/moped tire to fit it. Instead, I use the same solution I've done for a while now, which is to use a layered approach.
Regular tire liners, like the Slime things, have a tendency to wiggle and slip, not fully protecting the center tread area very well, unless you use really high pressures in a tire. If you want a comfy ride, you have to decrease the pressure, which lets them wiggle. You can't glue the liner to the tire, or else it won't deflect objects that puncture the tire, and they'll just puncture the strip, too. (their points won't be able to slide across it's surface, and instead will just go thru it).
So I've used two different methods to help with this. What I do now is take old tubes that have become unpatchable for whatever reason, and cut the valve stem off. Then I slit them along the inner circumference, and enclose the actual tube I'm going to use inside this. If they're not thick (3mm+) then I'll use two. If I have one handy when I setup a wheel, the slime liner then goes between this contraption and the inside of the tire.
I've also used an old semislick tire with the bead cut off, to do the same thing. I don't cut the tire to make it shorter to fit inside, I just pick a tire that's enough smaller than the one I'm using. That's difficult to find pairs like that in my used stuff, so that's why I now use the tubes instead. Same effect--makes it more likely to be thicker than the most common things that will stick in it (which is also the point of the moped/MC tires).
Both methods work very well, but they do make heavy wheels.
The slime liners work better at deflecting nails and stuff when used with the slit-tubes than with tires, probably because they can more easily deform to let the nail slip past and force it toward the sidewall, rather than being unable to deform and letting the nail poke thru the liner instead. But the tires themselves are harder and so are more puncture resistant to smaller more bendy types of debris.... Pick your poison.
The only time I have had trouble with tire-in-tire stuff is if I didn't cut the bead off, the wire in the bead eventually poked thru the tube and cause a flat instead of preventing one!
But others have sometimes had other issues with the setup; don't recall which ones.
I don't know anyone that had trouble with the multiple tube setup.
I know I've seen some extremely thick and heavy tubes, filled with goop, for sale, but they weigh more than the tire itself!!
Still, if it works...?
I've used Slime in tubes before, and it can work, but if you get a gash or something it doesn't usually hold even if it can plug it, and it makes it next to impossible to patch the hole on the roadside.
Regarding weight, unless you're using higher technology (kevlar linings, etc), which still isn't that common in bike tires (there are some, but not a lot, and not a big selection of treads, sizes, compounds, etc., in what *is* out there), then simply using thicker tires will do more than most other things to keep punctures minimized. Thicker tires are heavier, so if you need "extreme" puncture resistance, you end up with heavy tires, if you go down that path.
Basically it means you choose where the weight goes to, but you still end up with a heavier wheel, without some sort of high-tech lining.
Also, in the old days we had bent wire 'tack removers' for lack of a better term, that mounted under the brakes, and
rubbed the tire surface, to supposedly knock off anything before it imbedded itself. Not sure if they actually worked not.
They can work, but depends on what stuff, and what damage it already did to the tire.
Others have put what amount to brooms out front of the tire, too. Or magnets, etc. Depends on the kind of debris.
Otherwise, a leaf blower would fit under there,.. (just kidding :lol: )
That's been done, too (not by me)
From what I've seen, works best if you're riding pretty slowly, as the force needed to move the stuff out of the path is high enough to need to be fairly close to the outlet of the blower. One can use a narrower nozzle to concentrate the airflow, but then the path cleared may be too narrow. Placing the outlet directly in front of the tire, blowing at an angle toward the side, would probably be most effective.