Originally Posted by
rekmeyata
It doesn't cut the tire, it chaffs away at the tube which eventually puts a hole in the tube. HOWEVER, that can be stopped by sanding the overlapping edge to a paper thin thickness, and by using thicker tubes.
One problem with Mr Tuffy vs Panaracer FlatAway I forgot to mention earlier is that the Mr Tuffy does not stick to the tire upon installation, so you have to hassle with it like crazy to maintain it's position while putting the tube and tire back on both initial installation and flat repairs, even after you did all of that you have no guarantee that as you air up the liner stayed exactly centered over the tread, with the FlatAway it has a self sticking backing that prevents all of that hassle.
With ~37-42 mm tires it was fairly easy to keep the Tuffy liner centered when mounting tires. & I guess that one could use a bit of cement to tack the Tuffy into place. Never had a Tuffy-induced flat during years of use.
Mr Tuffy is reputedly not perfect vs goat's head thorns...FlatAway/Rhinodillo might be better. If I lived in thorn country I'd consider tubeless esp since I have 559mm/26" wheels. Tubeless rims & the goo add weight but can't one compensate with lighter tire? That might give better ride & handling than heavy-duty Marathons etc.