I have long been a fan of the original Gravelking SK in 700x38c. They provide good traction on everything but mud and are pretty much indestructible. The only downsides were that they make a lot of noise and feel like slugs on pavement. I recently built up a frame that has room for 50mm tires, so I entered the massive cloudy world of gravel tire choices. For a few weeks, I had so many tires rotate in and out of my cart, I read and watched reviews, asked friends, etc. I went the low weight route, I went the heavy duty route, I went the low rolling resistance route, then finally returned to my senses and asked myself what was important in a tire. I wanted a robust tire that performed well on and off road, looked nice, and wasn't going to leave me on the side of the road fitting a tube into a tire full of snot.
Enter the Gravelking X1 in 700x45c. These things are excellent! Mounting happened with my thumbs, bead seating happened with a floor pump, and they hold air forever. They roll very very well on pavement - a very noticeable improvement over their SK predecessor, they grip chunky gravel beautifully, they're wide (48mm on 26mm internal rims) so they do well in sugar sand so long as you maintain power, and they are quiet! Weight is fine. They aren't light, but they aren't dogs either. I've driven these things over all types of surfaces while not being too picky in line selection, and they look damn near brand new. I can't comment on mud yet, but judging by the tread, I can't imagine they're much better than the SK.
If you run these tires, you have to get the pressure right. After a bunch of trial and error, a good starting point would be to take the pressure you run now and let out a heap of air. I weigh 195 lbs and run the 700x38 SKs at 30-35. The 700x45 X1s are happy at 16-20. Any more than that and they aren't comfortable at all - like full of concrete feeling.
Buy these if you want a tire that performs pretty much perfectly which you don't have to worry about.
Easily mounted these on carbon rims for my Creo e-bike. They are quiet on pavement, pick up few stones on gravel and ride and roll very nicely. They provide good feedback and grip on gravel.
I grew up riding bikes on gravel roads on pretty sketchy tires back in the 60s and since then have ridden on a variety of tires including Conti top contact on a ride from the Black Hills to Denver via gravel mostly. These tires are the best that I have experienced.
Put these on my 2008 Surly Long Haul Trucker, got some MTB platform pedals, and ride the rail trail of Santa Fe like a gravel guy. Fast on pavement, low rolling resistance. 50 psi on dirt/gravel, 60 psi on pavement.
Smooth rolling and great traction - super happy with this tire!!!
Upon reading some reviews of this years Unbound gravel course (north bound) I decided to go wider and add some more traction. My research pointed to GravelKing X1's and I snagged a set of the 45's. They did not disappoint! To break them in I rode single track up at Red Mountain/Soapstone open space in NoCo (north of FT Collins, CO a couple weeks before Unbound and I was pleasantly surprised how well they roll while also handling the rocks and sand. No regrets here. I have found my new go-to gravel tire!
Absolutely love these tires. They roll fast on pavement and handle well in dirt and sand. Put them through a 3 mile climb in a sand pit at the Bend Dirt Fest and rear wheel did well.
I've ridden these GKs on wet pavement, mud, dirt, gravel, and snow and have been impressed with their grip despot what I consider their subtle tread pattern. Run them at 45psi road and 40 psi trail. I gave them 4/5 stars because mounting them on my Bontrager Paradigm Comp 25 wheels required a Herculean effort. Perhaps it's the wheels and not the tires but it took a heat gun and a lot of sweat to get the last 4 inches of tire on the rims!
Huge improvement on the OEM tire that came with my Revolt. Definitely heavier but still very fast and great handling on road. Only knocking off a star for the painful installation. I gave myself blisters getting these on with a heavy pair of work gloves but kept at it until they popped on. I will say that the seal is amazing probably for the same reason.
Decided I needed a wider tire for SBT GRVL this year so purchased these in 40mm width. Easy to mount. Great handling and feel like they roll faster than either the 35mm GK SS or 38mm GK SK that I have put several thousand miles on over the past few years!
I have put over 350 miles on these tires so far on some rough roads and even some trails and they have held up well! They roll fast, might not be the best for cornering, but again, pretty great for an all around tire. Would recommend!
I needed something with more grip than the Gravelking SS I had but didn't want to add much rolling resistance. These X1's don't feel like they slow me down at all and make very little noise when rolling fast on pavement considering how much tread and grip they have. (Note: the 45mm tires measure 46mm in case anyone is curious)
Able to seat tubeless with a floor pump. Traction on a variety surfaces (haven't been in any mud yet)
