Panaracer's GravelKing SK 27.5x1.9in tires have a similar outside diameter to a big 700c tire. Where they differ is that the 27.5in tires have much more air volume for a softer ride and a larger contact patch for added traction.
Now, before anyone gets too bent out of shape, Panaracer lists these tires as 27.5x1.9in with the even more confusing 650bx48 size in parentheses.
Panaracer GravelKing SK tire specs
- Compound: ZSG natural rubber compound
- Casing: Anti-flat
- Puncture protection: AX-Alpha Cord for cut and abrasion resistance
- Size tested: 27.5x1.9in (650bx48mm)
- Actual weight: 562g
Supple and comfortable
When mounting up the GravelKings, I was curious to find out what the benefits and feel were going to be: slow, soft and cushy, or loads of traction.
It turns out that they displayed only one of the three: soft and cushy. The GravelKing SKs featured a supple-feeling ride. Small bumps and road chatter lost their edge, chunky hits where I winced in fear of a puncture lacked the jarring slap. And I didn't flat. I rode them mostly around 35–40psi.
Of course, that luxurious ride did have a little tradeoff in terms of speed, primarily on the pavement. The GravelKing SKs definitely don't have the slingshot efficiency of a lighter, thinner tire, but it's a bargain I'm more than willing to accept.
On dirt roads and paths, the rolling efficiency felt similar to other gravel tires. When the gravel got looser, the GravelKing SKs did have a bit of float and vagueness about them as the big, low-knobbed tire slid on top of the surface instead of slicing through.
To my surprise, durability has been impressive with excellent wear and no cuts or ripped tread blocks and, as mentioned earlier, no punctures.
When looking at fast-rolling tires, there's a reason the center tread is often a continuous or a nearly unbroken line of knobs. Tread like this is fast and provides minimal rolling resistance.
There's also a reason why the side knobs have more spacing. More breathing room between knobs equals more biting edges to contact the ground and provide traction when leaning the bike over. Side knobs should be about traction, not efficiency.
The GravelKing SKs sort of have this backwards. Its side knobs are almost a continuous tread, and other than some perpendicular little knobs there are few working edges to grab the ground and guide you through the turn.
Given the size and width of the GravelKing SKs, a little more side knob spacing and some bigger, burly tread could really put these tires into a class of their own.
Panaracer GravelKing SK vs the competition
WTB's 27.5x47mm Byways are the main challenger in the road plus tire world. On my scale, the Byways are lighter by 59g but feature significantly fewer knobs throughout.
With a slick center tread, it's clear the Byways have smoother roads in mind, which is somewhat counter to what gravel riding is about, at least in my opinion.
Compared to other gravel-specific 700c tires, such as the Maxxis Rambler, Kenda Flintridge, and Donnelly X'Plor MSO, the GravelKing SKs feel much more supple and comfortable. The added layer of forgiveness and reduced vibration are immediately noticeable.
Panaracer GravelKing SK bottom line
If your current gravel/adventure/dirt road bike feels a bit too harsh, the big, cushy GravelKing SKs are a good way to add forgiveness to your ride. Even with the added suppleness, they give up little in terms of speed for most gravel-based adventures.
They're also an excellent tire when your gravel rides get super chunky and rough. The biggest benefits being the added tire volume, which takes the edge off of hits and reduces vibration.
Unfortunately, they don't take full advantage of their cushy, capable ride as the side knobs are oddly shaped and don't deliver the cornering performance to match the rest of the tire's attributes.