The growing genre of gravel tires is roughly split between two camps: adventure and race. It seems a little like the split between XC and gravity MTB tires, with some intermediate trail options to fit particular uses.
The Gravel King SS and SS+ tires from Panaracer sit firmly on the race side of the equation, with an asphalt tread in the center, and some small grooves on the sides to add cornering grip on hard-packed gravel. At sub-400g they’re undoubtedly designed to save weight, which solidifies their place in the go-fast category.
The smooth Panaracer tread comes in a 700c diameter with 28, 32, 35, 38, or 43mm widths, and a 27.5″ version that’s a ballooning 48mm (1.9″) across. Gravel King sidewalls are available in tan or black, with a lightweight SS casing or the SS+ that adds a bead-to-bead puncture protection layer called ProTite.
Apart from the 28mm width all of the tires are tubeless-ready, and they set up as easily as any skinny mid-pressure tire. I tested the SS+ casing in the narrower 700x32mm width because our local gravel roads and XC trails are fairly hard-packed, and there’s no real need to roll a larger tire patch. Narrow tire casings require a direct and immediate blast of air to seat the bead, so I removed the valve core before connecting a Bontrager Flash Charger pump to force a storm inside. With the second set of Gravel King SS+ tires I received the setup went fairly well. They have been holding air as well as any other tire in my chilly basement.
I couldn’t get the first set of tires that Panaracer sent to set up tubeless, no matter how many dragons’ breaths I bellowed. The beads were simply too loose. I added another layer of rim tape, used soapy water on the beads, chanted a riddle to the great tubeless goddess, and phoned a friend. No dice. I had just removed a set of tubeless road tires from the same wheels, so the issue had to be in the tire. Given that the second Gravel King SS+ pair didn’t throw a fit I have to deduce that there was some issue with the first set.
I installed tubes in the tubeless-refusing tires and mounted them on a different wheelset where they work just fine. While many gravel enthusiasts will likely mount a more ample width, which is typically easier to set up tubeless, it might be worth purchasing these tires from a local dealer in case you get a pair that doesn’t fit snug enough.
On the open dirt-road the Gravel King SS+ tires roll easy and they feel fast. Mounted on my Breadwinner cyclocross bike, with a ‘cross-legal width of 32mm, they grip similar to a classic file-tread clincher that I might mount up for a race course with loads of grass or hard-packed dirt. If I were purchasing tires for a true gravel race or event, the 32mm Gravel King SS+ from Panaracer would make my short list.
Cornering grip on these tires is better than that of a road tread, but it’s definitely intended for sunshine riding. On dry hard pack, the cut-in cornering grooves grip little stones quite well, and they seem to hold on better than a road tire if you need to feather the brakes mid-turn. Panaracer has a wide variety of gravel tires if you want additional corner tread, and these are one of their lowest and lightest offerings.
The Gravel King SS+ feel slightly slower than the 32mm slick road tires that I had mounted up prior, and the extra effort I’m sensing is undoubtedly coming from the lower air pressure allowances. Those other road tires were pumped up to 75psi, whereas these feel best with 40-50psi. While I am riding the same roads on both sets, the lower pressure allowance and tougher sidewalls in the SS+ mean that I get a smoother ride with less fatigue. For a long backroad adventure, that little pillow effect makes a meaningful reduction in overall body fatigue. If I were riding rougher roads that require more tread and cushion I would drop off the drop-bars and hop on a comfortable cross-country whip with 29×2.35″ rubber.
Finally, I did not manage to flat these tires, which is as important as any note above. I did hear a few rim-strikes on rougher roads, and while hitting potholes and roots mid-descent, but between the sidewalls and the Panaracer Sealsmart tubeless sealant I didn’t experience any issues after mounting this pair up. I also don’t have any latex splattered on my frame, so I think the SS+ casing did its job well.
Panaracer Gravel King SS+ tires retail for $59.99.