I know, this is an old post, but people researching infor about liners will stumble across this forum discussion. All the weights I will be describing are for the narrow road version.

So anyway, Mr. Tuffy's liners are a bit on the heavy side, in my opinion, however, they now have Ultra Light liners. The regular Mr. Tuffy's weigh 154 grams for a pair or 77 grams each with a thickness of 1 mm; the newer Mr. Tuffy Ultra lights weigh 105 grams for a pair or 52.5 grams each with a varying thickness from 0.8 to 1 mm due to the ridges. The Ultra Light liners have ridges going down the length of the liner, this is to prevent the liner from squirming as the tire ages. Both versions of Mr. Tuffy are reusable.

Another decent liner made very similar to Mr. Tuffy in the materials it uses but is a bit thicker at 1.20 mm is the RhinoDillos, while it is a thicker liner it weighs 136 grams for the pair or 68 grams each which puts it in about the middle of the road in weight between the Mr. Tuffy regular liner and their Ultra-Lite liner, also reusable.

There is also the Zefal Z liner, this liner is the lightest of the polyurethane liners it weighs 70 grams for the pair or 35 grams each, I could not find a thickness scale but I would assume they are around 0.8mm and these have no ridges.

Finally, there is the Panaracer Flataway liner, these are the lightest at 50 grams for the pair or just 25 grams each, they are about 0.8 mm thick, these are made differently using kevlar instead of some sort of polyurethane as the all the other ones on the market use, this liner is the most expensive and it is NOT reusable you throw it out with the tire when it wears out.

Mr. Tuffy tried to take a dig at Panaracer by claiming that Kevlar doesn't stop pointy objects from separating the threads and hitting the tube as Mr Tuffy does, well if this was true then why do almost all tires made today use Kevlar to prevent flats? The Schwalbe Marathon series all use a polyurethane liner. While no tire is flat-proof neither is no liner flat-proof.

So which is the best? I've used both, and I can't really say! I do know that if you take a pair of scissors and try cutting a poly tape it cuts like butter whereas the Kevlar liner I had to saw it with the scissors and was hurting my hand trying to cut it; I also know that I was able to penetrate a nail tack sort of easily through the poly but the tack bent when I tried to penetrate the kevlar. However, the huge drawback with the Kevlar liner is the cost which you have to keep paying for a new liner every time you replace a tire. The drawback with a poly liner is that the leading edge of the liner over time can rub a hole into an ultralight tube which means ideally you should run a thicker tube which adds even more weight to your wheel-tire combination, supposedly the Rhino liners have a soft edge that prevents that. What I use to have to do with the regular Mr. Tuffy liners is sand the edge of the liner that was going to be in contact with the tube to almost a paper-thin thickness, once I did that I never again got a hole in the tube from the liner edge, I'm not sure if the thinner Ultra-lite and the Zefal liner will cause that same issue. Also, since the Panaracer Flataway is a cloth substance it does have a tiny bit of cushioning effect between the pavement the tire, and the tube, not sure if anyone would notice it though, but Panaracer claims it's there.

I use to use the Mr. Tuffy regular, and still got some flats from Goatheads thorns, I then switched tires from a kevlar belt tire to a Specialized Armadillo All Condition tire and never got a flat again without using any liner, but the Armadillo was using a thicker poly belt in addition to nylon belts. I later still used the Panaracer but I had moved from Goathead valley and wasn't getting flats anyways, however, I use them in my commuter bike's rear tire only to prevent the hassle of fixing a flat back there when trying to get to work or home, but I don't like the idea of replacing them either. So I've decided to add a bit more protection to my touring bike which will be using Schwalbe Marathon Supremes to use a lightweight poly liner since it's replaceable, and then only on the rear tire.

Just some observations and thoughts for anyone interested.