I’ve spent a couple years riding a pair of 120tpi Surly Knard 29 x 3″ tires. I use them mostly for bikepacking although I have rocked my Surly Krampus on trail rides now and again. The tread is now starting to show some wear, but for non-technical riding they’ll keep rolling another season or two. So far only 2 flats and both were before I went tubeless.
Setting the Knards up tubeless on some Rabbit Hole rims was easy using the split tube method. They have been 100% reliable with no flats and I can leave them 2 weeks+ without adding air.
For non-technical riding [ie. logging roads] I’ve found the Knard to be an excellent tire. It rolls quickly, provides solid traction and its big volume floats over loose terrain with ease. Even when I have encountered snow and mud on non-techy rides I have liked how the Knards worked for me. If you are forced to ride 100kms of pavement on a tour you will not hate life on these tires.
Where the Knards have shown their limits is in challenging technical riding. For me the biggest issue has been loose dirt/gravel especially on off camber trails. The front Knard just doesn’t have the side knobs to grab into the trail and keep the bike tracking straight which means you either go really slow or your front tire washes out and you crash. 😦
The very tall and wide [for normal MTB rubber] 29 x 3″ tire smooths out rough terrain, keeps you rolling fast and floats through softer conditions with speed as well and control. Despite the extra weight you can moving around I find the Knards let me move up and down just as fast as skinnier tires. The large volume also makes riding a rigid bike quite pleasant on all but the most broken ground.
Wanting a slacker front end I have mounted a Fox Float 34 fork on my Krampus and jammed the Surly Knard + Rabbit Hole rim combo in there. It requires the removal of a small amount of the fork brace to fit this big tire inside.
I have used Knards on skinny Stan’s Flow rims and 50mm Surly Rabbit Hole rims. If I was starting over today I’d build up a set of 35mm carbon Light Bicycle rims for my Krampus to get a nice blend of stiffness, lightweight and wide enough rims to support the 3″ tire.
All in all I think Surly’s first 29+ tire is a great option for bike touring and non-technical riding. I just bought a lightly used set of 120 tpi Knards from a rider on MTBR.com so I’ll have some Knards to keep me going for another few years of bikepacking.