i just recently started commuting with my roadbike and, while i really should have thicker tires (bike wont allow), i would like to line my tires to prevent the flats. has anyone used either the spinskins or mr. tuffy with any success? please advise, thanks.

You'd probably get more responses on the commuting forum. Though I've wondered before whether people use these for long distance rides.

I commute on an old rigid mountain bike, with 26x1.6 smooth tires. After getting two flats in the first 600 miles of commuting, I got Mr. Tuffys. In the 2500 or so miles since then, I've gotten 3 flats, but one doesn't count because it was from the valve stem getting cut on the rim hole. The other two were a sharp stone and a piece of glass hitting just right so that they punched right through the tire and the Tuffy to make a fast leak.

But for all the glass I see on the road and the hundreds of little cuts in the tread (sometimes I go around the wheels and pull glass out, and I always get plenty), I think the Tuffy is doing its job of blocking and grinding to powder all but the most formidable shards.

For long distance rides, I don't use either, in fact I don't use "flatproof" tires because of higher rolling resistance. Four flats in four years of randonneuring is not a problem :-)

For commuting, I'm still working my way through my stock of flatproof tires, and I can always tell when the rubber is getting thin because then I get flats where my commute crosses a wooden bridge with splinters. So much for the Kevlar belts.

I've used both the spinskins and the Mr. Tuffy. The Spinskins are expensive, and they wore out inside my bike tires in about two years. Go figure. The Mr. Tuffy's don't wear out, but they sure make it hard to get a piece of metal back out once it has punctured through the tire and through the Mr Tuffy and on into the inner tube. I had to wait until I was at home with the vice grips.