The first thing I noticed is that these are heavy tires! They fold nicely, as advertised, but they weigh in at 5lbs according to my scale! (As opposed to my old Kenda Juggernaut Sports that were 3 lbs, and those were 26x4.5, not 4.0!). Sidewalls are thick, .115" to be exact, which is 4x the thickness of the Juggernaut! It is a very stiff sidewall!
Ride quality:
I played with air pressure in these tires to see how they reacted. These tires should be run at 20PSI, especially on dry pavement. Rolling resistance is minimal, and they are silent running. Running over a 2x4 at low speeds did not produce much bounce, but you noticed you hit something. Auto steer is not a problem at this pressure. Riding on the grass took some effort. On level ground, these tires like to maintain speed. Going downhill, these tires love to gain speed, their mass really works in your favor! Uphill, it is a little effort, but at 20psi, it really isn't that bad.
Riding these tires at lower pressure is not recommended. At 10psi, autosteer became noticeable, and going uphill is great exercise for leg day! At 5psi floataion kicks in and riding on the grass becomes a joke! However, riding on pavement becomes a chore. Autosteer becomes pronounced, and braking while turning is an adventure. There is a reason the sidewalls are stamped 20psi. That is the best pressure to run these tires at!
Puncture resistance:
I broke down some pallets, and I have a couple different nails to can put in the wood. One has a sharp point, the other has a blunt 1/8" flat point. I inflated the tires to 20psi and started running over stacks of wood. I started with the flat point first, exposing 1/4", then 1/2" and finally a full 1" of nail. This tire took all of it, both front and back! It actually bent the blunt nail down on my final test! (The first time I saw a tire flatten a nail!)
The sharp point was a little different. The tire withstood 1/4, but that was it, 1/2" and longer punctured the tire. (It did take two tries to pop the front, as there is less weight on that tire). One other note, as the tires deflated, they will come off the rim once the pressure gets low enough. Where the tires were folded during shipping seems to be the most fiddly part.
I used no tire liners or slime in the tubes. I imagine these would help things a bit!
Overall, these are solid tires. When inflated properly they handle well, and ride smoothly and silently. I will keep this set on my Gravity Bullseye Monster and play with it on the hard gravel of the Mon bike trail. I wanted to put these on my fat tire trike, but the rolling mass is a bit too much, and I want to ride them a little softer for suspension effect. These tires do not like that.
But I do believe in clean dry conditions, these tires are pretty good! In the city, these look like a nice option on a commuter and they will shrug off the odd road hazard. As advertised, they are puncture resistant, not puncture proof!