700×40 Tire Roundup

If you ride a production (read, mainstream) gravel or adventure bike there’s a good chance that it came equipped with 700C wheels and tires. While the debate over optimum tire width for gravel rages on, it’s generally acknowledged that 40 millimeters is the cutoff before one enters into monster cross territory. And just like gravel bikes themselves, tires designed for gravel and adventure riding are often open to interpretation.

I spent the past couple of months testing 700×40 versions of Kenda‘s Flintridge Pro, the Maxxis Rambler and Re-Fuse, and Panaracer‘s Gravelking SK. Each of the tires saw a mix of recreational and utility riding on terrain that included pavement, dirt, and of course, gravel. Thanks to Colorado’s ever changing weather, I also experienced first hand how the tires handled on snow and ice.

Tubeless road tires may be lagging behind their mountain counterparts, but these four models confirm that tubeless compatibility has become a must-have feature for gravel use. As with tubeless MTB tires, ride quality, comfort, and traction improved when the tires were ridden sans tubes. I tested each tire with various sealants–including Caffélatex and Orange Seal–and didn’t encounter any incompatibilities (such as blistering or delamination).

Model Width
(mm)
Weight
(grams)
Pressure
(psi)
Price
(USD)
Kenda Flintridge Pro 40.4 479 30-50 $59.99
Maxxis Rambler 38.2 378 75 $64.00
Maxxis Re-Fuse 38.1 525 75 $64.00
Panaracer Gravelking SK 40.7 486 60 $49.99

To insure consistent measurements, each tire was inflated to the maximum pressure and left for 72 hours. Tires were then inflated to 50 psi and the cross sections measured at the tire’s widest point. All measurements were taken using the same alloy rim with an internal width of 19.3 millimeters. Weights are the average of two sample tires using Feedback Sports‘ Summit digital scale.

 

Kenda Flintridge Pro
kenda f-pro 700x40 qtr view
kenda f-pro 700x40 side

Named for the Flint Ridge hills of Kansas (home of the Dirty Kanza 200), Kenda’s Flintridge Pro is as tough as its namesake. The tightly-packed tread is smooth and quiet on pavement, but still offers the necessary traction on hardpack dirt and gravel. Measuring a plump 40.4 millimeters, the 120 TPI casing provides excellent flotation and cushioning–if you drop the pressure a few pounds. The Flintridges’ sidewalls are on the stiff side, so I found myself gravitating towards the lower end of the tires’ 30-50 PSI range. Kenda specs the Flintridge Pro with the company’s DTC dual-durometer tread (60A center, 50A side), but to be honest, I couldn’t detect any improvement in cornering traction compared to similar, single-compound tires.

Maxxis Rambler
maxxis rambler 700x40 qtr view
maxxis rambler 700x40 side

Maxxis classifies the Rambler as a gravel and dirt road racing tire, and I’d have to say they’re dead-on. First, the Rambler is seriously light. Tipping the scale at 378 grams, it’s 100-147 grams lighter than the other tires in this roundup. That light weight, however, comes (partially) at the expense of air volume. The Rambler’s casing measures only 38.2 millimeters, but even with the tires’ reduced width, the ride quality doesn’t suffer. Of all the tires I tested, the Rambler had the most supple sidewalls. If you haven’t made the jump to tubeless, this is one tire where running inner tubes doesn’t significantly hamper performance and comfort (even with the EXO sidewalls‘ added protection).

Maxxis Re-Fuse
maxxis re-fuse 700x40 qtr view
maxxis re-fuse 700x40 side

Remember what I said about gravel and adventure tires being open to interpretation? Well, Maxxis’ Re-Fuse proves that dirt and gravel tires don’t always need knobby treads. Although the Re-Fuse’s diamond-knurled tread looks like what you’d find on a traditional road tire, it’s surprisingly capable off-road when you drop the pressure. Whether you’re riding dirt or pavement, though, it’s best to take the Re-Fuse’s 75 PSI rating with a grain of salt. For mixed-surface rides I typically ran them at 30 PSI front and 40 PSI rear. For extra durability, Maxxis specs the company’s MaxxShield protection, which combines the company’s SilkShield bead-to-bead protection with a K2 layer. The result is a casing that’s stiffer than some high-performance tires, but extremely resistant to sidewall cuts and punctures.

Panaracer Gravelking SK
panaracer gk 700x40 qtr view
panaracer gk 700x40 side

Although the other tires in this roundup are relatively new offerings, Panaracer’s Gravelking has been available in various configurations since 2014. The 700×40 SK version that I tested features the same knobby tread found on the company’s 700×32 model, as well as tubeless-compatible beads and casings. Like its narrower counterparts, the SK’s supple casing offers a smooth, comfortable ride. With its ample 40.8 millimeter width (and tall profile), there’s plenty of rim protection for roots, rocks, as well as broken pavement. The tires’ small center knobs provide good traction on hardpack dirt, but I noticed a slight dead spot between the first and second row of side knobs (although you have to lean the tire over pretty far to feel it).

Summary
It’s great to see manufacturers offering more gravel and adventure tires–especially tubeless compatible models. So which is the best tire for you? Best is a pretty subjective, and it all depends on your requirements. If you value dirt and gravel performance, but still want a smooth ride on pavement, check out the Kenda Flintridge Pro or Panaracer Gravelking SK. For mixed-terrain riding where knobbies aren’t required, I recommend Maxxis’ Re-Fuse. And if you’re looking for a competition-worthy knobby, consider the Maxxis Rambler (especially if your frame/fork don’t have clearance for bigger rubber).

Disclosure: Kenda, Maxxis, and Panaracer provided review samples for this article, but offered no other form of compensation in exchange for editorial coverage.

15 thoughts on “700×40 Tire Roundup

  1. You say the “Maxxis’ Re-Fuse proves that dirt and gravel tires don’t always need knobby treads” but you recommend the Kenda and Panaracer for dirt and gravel? I have been considering trying the Compass Barlow Pass 38c tires (380 gms) instead of my Conti CycloCross Speed 35c (350 gms) tires. But am undecided about giving up the knobs with the 60% dirt roads we ride. Not sure how the smooth tires will handle the looser sections. How about a true comparison?

    1. First, some background. My commute ranges in length from 10-13 miles, depending on the route. Approximately 20%-30% of that is dirt and gravel. The gravel here in Colorado’s Front Range tends to be pretty mild (kitty litter consistency), so it’s neither too sharp nor too deep.

      The Compass Barlow Pass is a wonderful tire. I commuted on both the standard and extralight versions for close to a thousand miles and experienced only one or two punctures. The tires are incredibly supple, and they’re a joy to ride on non-technical dirt roads/trails. Do the Maxxis Re-Fuse ride as nicely? No, they don’t. But, the Maxxis are tubeless compatible, and that’s a higher priority for me (right now).

      I, personally, don’t find that tread makes much of a difference in loose conditions. As I mentioned, the gravel here is rarely that deep. If I have to choose knobs over width/footprint, I’ll take the latter. That said, if I was riding someplace where I wasn’t familiar with the trails, etc, I’d opt for a tire with some tread. For example, you wouldn’t find me on slicks/file treads if I was riding this event.

      Hope this helps.

      1. For mostly Chip and seal, Apparently I’d be better off with Barlow with tubes rather than the heavier tubeless Re-fuse? My end game is the widest I can go up to 38 with the least amount of rotating weight. (So I can stay with the SKS P45 fenders)
        I suppose schwalbe G-one is a contender also if I want to run tubeless, and on going tubeless I’d probably pick it over the Re-fuse. My other goal is a year round tire. Outside of Contis winter contact tread sucks on ohio snow. Which I am thinking makes the G-one a no go. I loved the ride of the 60TPI MSO 40 I juts has negative experience with them on snow on pavement. I came from running 28 slicks.

        1. Barlow Pass with tubes will ride very nicely. To be honest, though, I’ve never found a non-knobby tire that worked well on snow of any significant depth.

          1. with enough snow depth and a softened snow surface in the sun, then some knobby tires work. My experience has been I am usually better of with a slicks. Ohio is weird though, Actual riding on packed snow is like 1% of all winter riding? It snows, it melts, Usually we just deal with wet icky grimy salty sandy roads. I also have to travel 2 hours by car to go find real gravel roads. All I ride is chip and seal. Which apparently is more like gravel and seal now, vs chips. Oh and our driveways around here, are half mile long and gravel.
            Oh and I’ve always been selective on when I rode, being fenderless, and they way they salt roads I just didn’t ride salted snow. I either rode the snow before the plow trucks ran, or I waited a day for it to dry then I rode. This will be my first winter fendered, and riding crap roads.

  2. There is no such place as the Flint “Ridge” Hills in Kansas. It’s just the Flint Hills. I’m sure this is a marketing naming scheme to make it feel like these tires are meant for sharp flint rock gravel like there is in the Flint Hills. Minor detail.

  3. How do you think these tires compare against CX tires like Continental Cyclo X King and Schwalbe Smart Sam?

    I’m riding a CX bike mostly wood paths with moderate mud, roots and bumpy surfaces, some hardpack and gravel.

    The bike takes 40mm tires (Smart Sams) with no issue and I could squeeze in up to 45mm in the front. What I’m looking for it more volume. The bike can take more wheel diameter but not much more tire width in the rear chainstays.

    What would you recommend here volume-wise? The u-shaped tire would give and advantage over Smart Sams?

    1. I’ve not ridden either of the tires you mention.

      Do you want more volume? How wide are your current tires (actual width at the psi you normally ride)?

  4. I have the Maxxis refuse 32 and agree with your summary. I am very happy with them will and keep them on as a all around tire. I also have the Kenda flint ridge pro 35 but they measure 40 on the rims. Would like them better if they were a true 35. The kendas have speed and agility on gravel but are heavy on the road, not slow but sluggish.

    1. I, personally, haven’t used Stan’s rims. My testing was limited to Velocity and Zipp rims.

    2. Maxxis Rambler does not fit well on my No tubes Avion. Almost as if they’re to big.
      I needed to use an inner tube to make them hold air.

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