Rerun: the Panaracer GravelKing SK

Rerun: the Panaracer GravelKing SK

It’s not uncommon for me to show up to a ride and have friends ask what I’m on. Given that I review stuff, what I’m on is constantly changing. I know that such work carries the strong whiff of adventure and novelty. I know this because I recall what it was like when I first started, and then stopped, and then started again. But I have an admission to declare, one that will get me a sympathy score of something like -5 on a scale of 1 to 10.

When I run across something I really like, when I encounter something that noticeably improves my experience, I don’t want to switch it out. I am, first and foremost, a flow junkie. Anything that increases the likelihood that I will get to church on time, or at all, is something I don’t want to give up. This is why reviewing road tires was beyond boring for ages. Most of them were so similar, it didn’t much matter whose tire you were on. All the $30 training tires road okay, while all the $70 open tubulars livened my experience like putting salt on watermelon.

I’ve ridden a bunch of gravel tires now. Many of them work well. A few completely blow for my use, but are probably fine in other realms, while a handful require you to wear sunglasses as you mount them because they are so awesome they shine like a welding arc. Tires of that character inspire weird urges in me, like doing crazy hard rides in an effort to wear the tires out a bit quicker.

The 38mm tire, ready for action.

When I first tried the Panaracer GravelKing SKs, I did some serious miles on the 40s and some rides on the 32s, though not quite so much because a 32mm tire is of, shall we say, limited merit on our dirt roads.

I fell in love with the 40s and struggled to comprehend how a tire so big could allow me to do 28 mph in a paceline. I mean, what gives? I could roll over any rocks I encountered and they were as unlikely to flat as my kids are to stay silent.

Then, Panaracer adjusted the line. Honestly, when I got the press release, I was terrified. I didn’t want them to change a tire that I adore. After talking to my contact and doing some deep breathing exercises, I was able to relax. Panaracer added some sizes and then reassigned a size to one of the existing tires. The 40mm tire I’d ridden previously was a big 40. They measured it on some of the popular wider rims that are available and have now designated it a 43mm tire, which strikes me as a more accurate figure.

The GravelKing SK now comes in six 700C sizes: 26, 32, 35, 38 and 43, plus a 650×48 (I earlier reported that there was a 28 in this tire, but that was incorrect). All are tubeless except for the 26mm tire, which require tubes. I can grant that in many circumstances that the 43 was a bit overkill, but hot donuts man, that thing sure did inspire confidence! And while a wider tire is less aerodynamic, it’s worth noting that those bigger tires have a larger diameter, which means they have better rolling resistance.

And can we go back to the sizes for a second? Six flippin’ sizes! I mean Trojan only makes two sizes of condoms. Opening tooling for seven sizes of tires is an incredible expense and illustrates Panaracer’s monumental commitment to the gravel category.

The 35mm size, with some post-race spice.

Of late I’ve been riding the 35 and 38mm tires. The 35 is what I ran at the recent Super Skaggs Grasshopper and rarely have I run a tire that felt more perfect for conditions. I was able to stay in the peloton with a minimum of effort for that first hour of the race. With pressure at a modest 38 psi front and 40 psi rear, they were sticky like a Jolly Rancher left on a hot car seat. Don’t ask how I know how sticky that is. I was able to roll blind into turns with broken or gravel-strewn pavement and never once slid. On singletrack the bike never slid so long as a favored my front brake sufficiently.

One interesting phenomenon I keep running into is when tires and/or wheels are too small. I’m done with 27.5 mountain bike tires, except for 27 plus stuff. If I want to crash, all I need to do is ride a mountain bike with 27.5″ x 2.2″ tires. I’m going down. Similarly, if I ride a tire narrower than 35mm on a gravel ride, I’m going to go down or flat, and maybe both. A 35mm tire seems to pass some threshold that allows the bike to float over certain obstacles that might otherwise capture my front wheel. For sure the front wheel is much less likely to get caught in a rut, and even if it sinks in one momentarily, it seems to pop back out without any real issue.

There’s a field of baby head rocks on the fire road nearest me. It’s a place of such hostility to bike tires it took me more than a year just to get to a point that I was comfortable rolling through it on a mountain bike without slowing or picking my line with care. I’m not willing to ride it on anything smaller than a 35mm tire and honestly, I’m nervous on anything smaller than a 38. Of the many tires I’ve ridden through that stretch, the 35mm GravelKing SK gave me the kind of confidence I’ve come to expect when running a bigger tire. That’s just a fancy way of saying that I never felt the rim bottom out against the tire.

The GravelKing SKs have been terrific in hard pack, sandy situations and, of course, quick on pavement. About the only circumstance where they don’t kill is in mud, and Panaracer has a tire just for that. I’m just relieved that I have enough wheels around here that I can leave one pair set up with a set of these tires. But which size to leave on?

Final thought: I don’t care if our roads get repaved.


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    1. Author

      I like the USH a lot, but it’s a clincher, not tubeless, so it won’t roll as quickly. Once off road I don’t think it grabs quite as well, but given the array of stuff out there, we’re talking the difference between a Lagunitas IPA and a Russian River Pliny the Elder. We’re not even discussing Coors. The lesser option is amazing.

  1. OttawaVelo

    Nice review!

    Is the ‘new’ 35 true to width, or still a little bit broad on a newer wide rim?

    I’d love to try the tire but my GT Grade can handle 37mm max.

    1. Jeff

      They tend to run a little big so a 35 could come out to be as wide as a 37 depending on the rim/wheel you’re using.

    2. MDGus

      OttawaVelo, just put SK 35’s on my GT Grade Carbon. They clear with plenty of room to spare. measure out at 37mm on 19 mm internal rims. Enjoy.

  2. Brian Ecker

    I’ve been running the SKs for several years now. They still amaze me at not only how fast they are but also how well they hook up on loose stuff. Over these several years I think I’ve flatted once. Huge miles no issues.

    1. David Woodward

      My only flat with the SK 35mm was from running over a curled-up safety pin (garbage day detritus), which levered up into the sidewall. Rode it the 7km to my destination as it slowly lost air, pulled the pin out and replaced the tube (which was chewed up) and noted the sidewall had sustained only the tiniest possible puncture. Has been fine in the 7 months and 2800km rolled since. LOVE these tires for touring with my road bike buddies – I can overtake them while riding on the gravel shoulders!😁

  3. Andrea

    I live in Sonoma County and ride these tires (40mm) on my steel frame gravel ride. They are comfortable and versatile for road, dirt, and gravel. In all honesty, if I’m considering a swift group road only ride with a fast pace, I naturally gravitate towards something else that will maximize my speed but that’s more about my ability level than the tire. For everyday riding and training in an area where “barely there” pavement and unsophisticated patch like attempts to fill pot holes is one’s playground for cycling, these tires are amazing.

  4. jayp

    The Baby Bear 35s are light and roll noticeably faster than the 43s. Aren’t that much smaller. The Momma Bear 38 therefore is the kind of compromise that politicians are no longer capable of…..
    It’s hard to argue that this huge array of sizes is bad… but it’s psychologically daunting…the opposite of the simple clarity that strictly limiting options forces on you. Like the structure of haiku or uh… limericks.
    Since SKs give more rubber choices than Trojan
    If YOU were a Kanza-bound man from Nantucket
    Would you pick 35, 38, 43…
    Or just reach blindly in your tire closet and say “f-it?”

    1. JayP

      (tire wonkery trigger warning!) I don’t think that’s right, but I’d love it if you have a reference that absolutely clears it up one way or the other..
      I’ve only seen references to Stephens riding 40mm and “40c” in that race, and that’s how he referred to them in interviews. There no longer is a tire in their lineup called 40, though there was then, the same tire that is now called 43.
      The super low tire pressures he claimed he was riding (26.5psi in the front!) support the idea that he was riding what’s now called the 43.
      The three pertinent sizes as labelled in the CURRENT Panaracer lineup are 35, 38 and 43. The 35 measures out at 38 on my wheels, 38 at about 40 and the 43… at 43. I won’t go into the name changes they had this year as it gets even more confusing.
      And all this is FURTHER confused by some 40mm NOS still on the market, and gum wall versions and the mud version blab blah blah.
      Stephens looks like he’s 25-30 lbs lighter than me and if he’s on 43s that would be a decent data point on the side of me not going smaller.
      Sorry to all who read this far…quite a muddy slog. But the question of which tire has been a big one for me in last few weeks. I really really don’t want to push those 43s 206 miles they are big chunks of rubber ….but on the day of I’m sure I’ll have so many other issues that I won’t notice.

    2. Author

      Jay, it might be helpful to you to know that you just corrected the North American manager of Panaracer. There’s a chance he knows what he’s talking about.

    3. Andy

      I like to run the 40/43 in the front and the 38 in the back. Reverse mullet style FTW!

      I’ve been swearing by these phenomenal tires since I first mounted the 32s, and have not had need to look back since. I’m excited to be soon trying out the OG Gravel Kings in 38 front and rear for a little more civilized rides.

      One thing I do note is that everybody who tries them seems to love the SKs, sadly, many reviewers then simply refer to them as *GravelKings* – chapeau for being thorough in both review and nomenclature. 😉

  5. Dolan Halbrook

    I have some SKs on my “adventure townie”, the 650bx48 variety, set up tubeless. So far they are great all around tires, if not particularly supple.

    Recently I found a pair of secondhand, low-mile 700×32 SKs for a whopping $15, so I’ve been running those on my gravel bike. For the fire roads on the Oregon coast, they might just be the perfect tire, though the 35s would probably be a touch better on the rougher parts.

    FWIW, the regular old Gravel King (non-SK) in 700×32 are a great low-cost alternative to Schwalbe S-Ones. Slightly more volume, smoother ride, great tread, and set up tubeless easily, at about half the price.

  6. JayP

    Padraig, I’m not with Panaracer, I’m a lowly journo. I think you meant to address that to “Jay” rather than “Jeff”?
    But yeah, I wasn’t so much meaning to correct as be enlightened, that’s why I was gentle and asked kindly for a reference.
    Simple recap why: He says “38.” The rider says “40.”
    So the question that begs is straightforward: Was the rider on the Panaracer tires labelled 35 that measure @38, the tires labelled 38 that measure @40? or the tires that WERE labelled 40 that measure 43?

    Those sizes, labels etc, BTW, aren’t mine. I got them from Panaracer US tech support.
    The guy there laughed and said yeah, it can be confusing given the recent relabelling of some sizes and slotting in of a new tire the ((the “38” that measures around 40))) right in the middle of the range that was relabelled.
    Regardless, I have all of them and just ran the 35s at Bootlegger 100, which may be the most technical gravel course in the country. Awesome rubber.

  7. Jeff Z

    @JayP, I was told by the team manager that Matt was on the 38, which measure out to 38-40 depending on the rim/wheel being used. I am double checking with the team now but they’re racing today (how inconvenient!) so I’ll get back to you. The team plans to go 38 this year unless conditions demand something else. Adding a mud tire to the GK family shouldn’t be confusing and was in response to market demand.

    As for the confusion in sizing, when we first set out to build the tire that became the GK (any version, standard GK for the slick tread, and added the SK (semi-knob) for better clarification on the tread) we were using standard rims with inner widths of about 17-21mm. Then the rim market exploded and everyone started to go wider, which changed the profile of the tire. With no standard in rim manufacturing even at the same inner widths, the tire was all over the place and not just ours. So we found those that were running the old 40c were using newer, wider rims. This effectively pushed the width up and we decided, since many bikes have specific clearance limits, to change the sizing. The addition of the 38c was to fill that much-needed gap between the 35 and the 43c. As for NOS in the market, nothing we can do about that. They are the same tire as what the 43 is that we now sell.

    All the GK’s run a little big. They will be exactly right on some rims and up to 2-3mm wider on others. This is simply a byproduct of where the rim/wheel sizing and market are at the moment. Hope this helps clear up any questions?

    1. JayP

      that clears it, and the history you describe that’s behind it — which affected any tire maker in the market segment — is a nice tidbit, the kind of interesting, value-added look at things readers know they’ll find on RKP …. as opposed to my wonky phrasing of the question, which probably gave people migraines.
      I’d been planning to run the 38s myself regardless but maybe go down to the 35s for more clearance and punch-through if it looks like we’re in for serious mud.
      thanks for taking the time to respond so thoughtfully.

    2. Chris

      Hi Jeff, seems you are with Panaracer? I love your tires but had a tubeless compatibility question. I have slick 32mm Gravelkings (non TLC) and have read on forums they are fine to run tubeless up to 55 or 60 psi. I have also experimented tubeless with a 650b 42mm Gravelking (non TLC) and the tire blew off at about 65 psi (on Velocity Blunt SS rims with wide 26.6mm inner width).

      So the question is…how safe is it to run 32mm Gravelkings (non TLC) on tubeless rims? Up to what width of inner rim? I love the feel of GKs but wouldn’t want to risk a tire blowout if I happen to hit bump which increases the inner psi.

      Or maybe a better question should be will there be TLC versions of the 32mm and 35mm GKs coming out soon? With a less stretchy bead? Thanks for any help

  8. Jeff

    @JayP. Anytime. We like to make sure people have the information they need to make the right choices. BTW, Mat DID run the 40 (now 43) at DK last year. And in a change leading up to the race, the team will be on the 43’s at this point for the 2018 DK.

  9. Elaine DeBitetto

    I just got a set of 35’s and rode them this weekend on the VT Monster course in Ludlow VT. They are GREAT on the pavement and very grippy on the packed dirt/loose gravel. Thoroughly impressed. I wonder if I need to hoard 2 more sets in case they decide to change them at some point.

  10. T. Guy

    Interesting that the only tire in the Gravel King Small Knob size series that is not of “tubeless” designation is the 26.
    Pushing the boundaries of faith, I have run my 26’s tubeless at 55 psi under my 160#. No problems to report, though I took no serious risks at any real speed or over pavement. Remind me , why aren’t the 26c GKSK tubeless rated, and why should I not run them tubeless?

  11. Chris

    Curious on the sizing. Using a 25mm outer and 20mm inner width rim with a frameset (Niner RLT RDO) that claims it can fit a 40mm tire, would you lean toward the 35 or 38 version of the Panaracer seeing that they are wider in real life than spec’ed?

    Thanks much.

    1. Author

      I’d run the 38. I’m reasonably confident that it will fit with that width rim.

  12. Patrick McEnaney

    I rode the 35s on my birthday ride at Coast2Coast 200 in Michigan, it was sublime in all but the sandiest conditions. The tire makes me skip and giggle like a grade-schooler. I enjoy it like a smooth, nuanced bourbon.

    1. Author

      I’m almost inclined to check and see if anyone else has ever compared a tire to bourbon. I suspect not.

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