THE BEST GRAVEL TIRES | In The Know Cycling
Summary: Picking the best gravel tires for the surfaces you’re riding can make the difference between a fast, confident ride and a slow, shaky slog. When riding a mix of paved, dirt and loose, small and medium-sized gravel that’s spread around, my testing showed the best gravel tires are the 700c x 40mm Continental Terra Speed, available here (US/CA residents), here (UK/EU), and here at the best prices from stores I rate highly and the same size WTO Raddler available here, here, and here also from stores I recommend.
Picking the best gravel tires is one of the first things riders focus on. If you’ve come from the road cycling world like I and many of you fellow road cycling enthusiast readers have, we bring little experience to draw on in this search.
Unlike most road tires, gravel tires have an almost dizzying array of tread sizes, shapes, and patterns to choose from. Many come in a broad range of sizes and most are tubeless. And with the growth of gravel cycling, new gravel tires are being introduced all the time.
All of this makes it hard even for experienced gravel riders to sort through all the options.
Since picking the right tires affects the speed, confidence, and enjoyment of your gravel rides as much as anything else, I’ve done the combination of ride testing and comparative analysis I’ve not seen anywhere else to find and recommend the best gravel tires for you and me.
WHAT YOU NEED TO KNOW
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A comparative testing approach helps identify performance differences
GRAVEL SURFACES VARY GREATLY
Gravel is a generic term. While using it can help you distinguish from road or cyclocross or mountain biking, it doesn’t take you much further than that.
Just as there are different ways to do road cycling (like racing, climbing, endurance riding, recreational biking, commuting, e-biking, etc.) and sub-types within those (road racing, crit racing, time-trialing, track cycling, etc.), there are many types of gravel riding and a wide range of surfaces all called gravel.
When looking for the best gravel tires, the type of surface you ride is one of the most important considerations. That’s because gravel riding is done on a range of surfaces far broader than where you do road cycling or cyclocross racing and even mountain biking.
Think about your last gravel ride. It probably started on paved roads to get to the start and may have had more of it between the gravel sections of your ride.
Depending on where you live or the gravel course you’ve chosen to do, your ride might have included hard-packed dirt roads or roads with a loose dirt layer on top with little or no gravel in sight. That’s still called a gravel ride.
Perhaps there was a small amount of gravel spread around or mostly on the crown or along the sides. There may have been a fair amount of uneven washboard or ruts including some filled with water in the spring or after a summer rain.
Another gravel ride you’ve done or are planning could have sections with a lot of actual gravel, some of it densely packed and embedded in the road and loose and deep in other places. The gravel might be small and mostly round, similar to what you see on driveways, or it could be as large and jagged as rocks. Indeed, you may ride sections with good-sized rocks, some of them on the surface, some partially embedded in dirt roads.
You might also come across sections with deep truck-width tracks and ruts or roots, stumps, standing or running water, and sandy or loamy or muddy surfaces. You might find some of these surfaces on narrow single or double track trails or up (and down) 5-10% or steeper, steady grades.
Clearly, the best gravel tires for a mostly hard-packed dirt route with a little bit of small gravel spread around would be different than those you’d want for rides with loose, deep gravel or a lot of large rocks, ruts, and technical descents.
CLASSES OF GRAVEL
Recognizing the wide variety of gravel surfaces we ride, former US professional road cyclist and mixed-surface pioneer Neil Shirley came up with descriptions of four categories of gravel in 2017. Some added to Neil’s efforts or came up with their own definitions while others have written about one or two of these surface types in more detail.
With input from Neil, other competitors, and event organizers, I amplified Neil’s descriptions and wrote this post in early 2020 detailing the amount of each of the four gravel classes and paved sections you’ll find at 25 of the most popular gravel events in the US.
To recap and illustrate, I summarized the gravel classes as follows:
Class 1 aka “Dirt” – maintained, consistent hardpacked dirt with small-sized or no gravel
Croatan Buck Fifty (left) and Tour of Battenkill
Class 2 aka “Gravel” – loose, small and medium-sized gravel spread over the road or in the crown or along the shoulder on top of hardpack or softer/uneven dirt; some washboard and occasional 1-2’ diameter potholes; sand and/or clay sections without gravel
Clockwise from upper right Mid South (James Gann Photography), Coast to Coast, Coast to Coast (glowingrock), Gold Rush Gravel Grinder
Class 3 aka “Rocks” – unevenly sized, larger/sharper gravel and rocks, partly exposed/buried rocks, truck tire trenches and rain grooves
Lost & Found (left), Dirty Kanza
Class 4 aka “Technical” – big rocks/rock gardens, deep loose gravel, deep ruts, path-, lane- or road-width potholes or single- or double track paths/roads with rocks, roots, fallen trees or other large obstacles
Grinduro (King of the Ride – left), Hilly Billy Roubaix (James Doom)
To show the contrast of surface mixes you’ll find, look at a few of the most well-known gravel events. The Tour of Battenkill is a mixed-surface event with only 35% of the route unpaved. Of that, 80% is Class 1 and 20% Class 2. At the other end of the gravel surface spectrum is Dirty Kanza which is 95% unpaved and predominantly Class 3 (50%) or Class 2 (30%) gravel.
While those two are at the extremes, most of the popular gravel events are either predominantly Class 1 and Class 2 (e.g. Rasputitsa, D2R2, Croatan Buck Fifty, Barry-Roubaix, Crusher in the Tushar, Gravel Worlds, Rebecca’s Private Idaho) or Class 2, 3 and 4 (Grinduro, Coast to Coast, Hilly Billy Roubaix, SBT Gravel, Lost and Found).
Recognizing that many of us roadies gone groadie plan to ride some of these events or others like them, it’s clear that one type of gravel tire isn’t the best choice for all of them. Unfortunately, there isn’t an “all-around” gravel tire solution that works pretty well on all surfaces.
Instead, to successfully ride gravel, whether your measure is what place you finish or that you just have a good time wherever you place, you need to know what the best gravel tires are to get you across the mix of surfaces you are riding.
And if you just prefer to ride gravel roads and routes without ever doing a gravel event, you still are better off picking tires that are best for the mix of those surfaces.
TYPES OF GRAVEL TIRES
While some may think that choosing the best gravel tires for where you will ride or compete comes down to picking from tires of the same width, it’s unfortunately not that easy. On the other hand, it’s also not as difficult as trying to decode the mix of various knob sizes, shapes, and locations you see on different tires.
After researching the range of gravel tires sold by over a dozen leading gravel tire manufacturers, I found that most of them were designed to serve one of three gravel surface mixes and could be organized based on the size of the knobs they used.
To simplify this, I grouped the tires into three types:
From the left, Semi-Slick, Small Knob, and Big Knob tires
Semi-Slick – Tires with no knobs or with small ones only along the tire shoulders. These are usually 30-34mm wide and are best when you are doing gravel rides that are mostly Class 1 and paved road riding.
Small Knob – Gravel tires with smaller, shorter knobs running down the tire’s center. Some continue this pattern out onto the tire’s shoulders while others use bigger knobs there. These are usually best suited for rides where most of the rolling is done on paved, Class 1, and Class 2 surfaces. Their label sizes run from 35 to 38mm but many actually measure wider on modern gravel wheels and you can order some in still wider sizes if you are a less experienced gravel cyclist.
Big Knob – Tires with larger knobs that are taller and placed further apart. You’ll want these when there is a relatively high percentage of Class 3 and Class 4 gravel on your route. While some may think it wise to have these ultimate grippers and their 38-42mm labeled widths spinning beneath you on every gravel surface to take on whatever comes up, they are very slow on paved, Class 1 and Class 2 surfaces, usually not very supple or comfortable, and can make for a very long day.
Given that so many gravel riding situations and events are best suited for Small Knob gravel tires and that there’s more of them to choose from, I’ve focussed this review on those tires first. I’ll add reviews of Semi-Slick and Big Knob gravel tires at a later date.
WHAT MATTERS MOST
When choosing between gravel tires, there are a number of performance characteristics I look for.
Grip, Handling. How well a gravel tire grips whatever surface it’s on when going straight, accelerating, climbing and braking is certainly important. How well it handles and holds when cornering or changing your line on all manner of gravel surfaces is key to how much speed, fun, and safety you’ll have on your ride.
Comfort. The comfort of gravel tires obviously matters a lot in choosing between them. While you can lower your tire pressure or go with a wider tire to improve comfort, doing so may make for sloppier handling.
Rolling and Puncture Resistance. A tire’s rolling resistance plays a more important role in choosing between them when riding at 12-15mph on gravel than when riding a road bike at aero speeds in excess of 20 mph. Likewise, puncture resistance is also critical because you’re riding over a lot of objects that can flat a tire in a mile of gravel than you might see in a month of road biking.
Unfortunately, there’s not been nearly as much independent testing done on gravel tire rolling and puncture resistance as you can find about road bike tires. I have drawn as many comparisons as possible by curating the independent gravel tire testing done by Tour Magazine (subscription required), Tom Anhalt, Bicycle Rolling Resistance, and one or two other magazines (with less independence) for some of the tires I rode. For others, there’s just no good testing data available yet. Instead, you’ll get my unscientific take-aways from the comparison ride testing I did that’s described in the next section.
Installation. How easy or hard a gravel tire is to mount, inflate, seal, and remove is an important consideration especially for roadies less experienced or comfortable with tubeless tires.
Price. Fortunately, there’s not a great deal of absolute difference between gravel tire prices. And they certainly don’t cost nearly as much as other components on our gravel rigs that are less important to our performance and enjoyment. Still, the price of everything including gravel tires matters.
Other things that matter in gravel tire selection aren’t easily measurable or comparable. For example, tire wear is something I’d sure like to know but it’s hard to generalize since we all ride on different surfaces. Because the absolute price of gravel tires is one of the smaller expenses in one’s gravel gear budget, I would also prefer to have a better performing tire than a longer-lasting one. Of course, if the wear of a tire is known to be far greater than others while the performance difference is much less, that might play a bigger role in my purchase decision.
Some things our roadie backgrounds might suggest should also matter really don’t when it comes to gravel tires. Things like tire weight or threads per inch (TPI) or brand or whether you can get a tan sidewall are less important and perhaps not important at all.
Weight differences between the same types of gravel tires are small and essentially irrelevant compared to the weight of your bike, wheels, and all the bottles, food, tools, and other crap some of us carry on our gravel bikes to be ready for any situation. TPI is just one thing that goes into tire comfort and I focus on the performance outcome than the design input.
After noting all of the above things that matter most, I came up with four criteria that integrate many of them and speak to me more simply when evaluating a pair of gravel tires.
They are:
SPEED – How fast can I go on the tires?
CONFIDENCE – How confident do I feel riding the tires on the combination of surfaces on my route?
GROAD FEEL – An analog to road feel, how connected do the tires make me feel to the surface underneath me, how aligned is that to what my eyes are telling me and my brain is processing in ways that allow me to make quick decisions on the bike?
VERSATILITY – How capable are the tires on the range of paved and gravel surfaces I’m riding.
HOW I TESTED GRAVEL TIRES
Over a 4-month period in the spring, I rode a dozen different Semi-Slick, Small Knob, and Big Knob tires on a 13-mile course with a good amount of paved, Class 1, and Class 2 surfaces and a few Class 3 and 4 sections.
The course is situated in the Assabet River National Wildlife Refuge not far from where I live. Before heading there, I’d put my bike on the car roof rack and put another set of wheels in the back along with my bike stand, pump, toolbox, food, and water.
Once I got to the course, aka the In The Know Cycling Gravel Test Track, I’d head out for a lap or two on the wheels and tires that were on my bike. After stopping to make notes on what matters most (see above section), I’d put my bike up on the stand, switch wheels, adjust the disc calipers as necessary and head off for another lap or two, stop, make notes and head home.
Once home, I’d switch the tires and wheels I’d been riding that day. The tires that were on one wheelset would go on the other one and the tires that came of that other wheelset would go on the first one.
The next day, I’d head back out to the ITKC Gravel Test Track and ride another bunch of laps with the new tire-wheelset combinations, again making notes after each set of laps.
I’d usually turn back into a roadie for the next few days and test ride some of the wheels and other gear we’ve also been evaluating or do a Zwift ride if the weather didn’t allow for a productive road ride test.
Later that week or the next, I’d grab a couple of new sets of gravel tires, mount them up and do another couple of days of laps and note-taking at the test track with wheelset and tire switching between gravel riding days. After an initial couple of rides with all three types of tires on hand, I focused in on the Small Knob gravel tires since they were best suited for the gravel classes I encountered at the test track.
At the same time that I’ve been testing these gravel tires, I’ve also been testing gravel wheels. I’ve got a good selection of alloy and carbon wheels in the test cave including those with both 23mm and 25mm internal widths. Some of the wheels even double as gravel and road wheels. (See here for more about these and other gear we’ve been testing.)
Because tire handling and comfort can be somewhat different depending on rim material and width of different wheelsets (as well as the wheels’ hubs, spokes, and assembly), I made sure to test each set of tires for this review on each type and width wheelset.
And instead of using the same pressure for each tire-wheel combination, I was careful to set my tires to the specific level recommended by ENVE’s Tubeless Tire Pressure Recommendations chart based on the inner rim width, tire size, and my rider weight.
While I used these recommendations as a starting point, if I thought the tires were riding especially hard or the handling was a little mushy, I’d adjust the pressure down or up after a lap to see if I could get better performance from the tires.
While I appreciate that you may be riding gravel on wheels with 21mm, 19mm or even 17mm inner widths, I didn’t see much benefit testing these tires out on wheels those sizes. Tire performance – especially handling and comfort – diminishes as you ride on narrower rims. The inside rim width of most new gravel wheels (and all of those I’ve been testing) measures between 23mm and 25mm so I focused there.
Needless to say, I got to know the test track quite well. I worked the corners where I could really go all out to test the handling and the sections of deep and loose gravel to separate out the more and less versatile tires. There were great sections to evaluate the acceleration in soft dirt and loose gravel, where I could feel how differently the tires rode as the surfaces varied, how fast I could go on paved and hard pack dirt section, etc.
The weather also changed quite a bit in the spring and with it, there were changes in how wet or dry and how soft or hard the surface was. There were plenty of potholes filled with water earlier in the spring and those same holes showed partially buried rocks once they dried. I was still bumming about the premature end of the ski-season so I found a few places where I could keep doing slalom radius turns going downhill to see how well the tires carved or washed out on gravel.
And yes, much of this riding happened as a few other cyclists and many other walkers enjoyed the rugged and raw beauty of the wildlife reserve. On busy days, I had to do a lot of maneuvering that was good for testing line changes, braking, and pulling up my face mask. On other days when I got there early or during the week, it almost felt like a personal playground, except of course for some of those who already lived or were recently born there.
GRAVEL TIRE REVIEWS
For this update, I’ve evaluated and compared Small Knob tires best suited for gravel rides on paved, Class 1, and Class 2 surfaces. Some are also capable on Class 3 or 4 surfaces though it isn’t their strength. Others aren’t versatile enough for those more challenging surfaces.
The best gravel tires are at the top with lower-rated ones following them in order.
Continental Terra Speed – Best Performer Small Knob Tire
The Continental Terra Speed is the rare gravel tire that combines speed, confidence, and versatility across all but the most challenging gravel terrain.
Looking at the tread pattern and Black Chili compound label on the Continental sidewall, I wasn’t surprised by the speed. The small, elongated hexagonal and diamond-shaped knobs in the rolling direction make for good surface grip without being so large as to impede your forward motion.
And for groadies like me, the Black Chili name is closely associated with low rolling resistance tires if not the most comfortable rides. I found very similar performance riding the Continental Terra Speed on paved, Class 1 dirt and Class 2 spread gravel surfaces. It’s as fast as any gravel tire I’ve ridden for this review.
What surprised me was how fast it moved through deeper, looser gravel typical of Class 3 and Class 4 surfaces. Riding these 40mm tires on 23C and 25C wheels at a good clip of speed, I felt the sensation of riding more along the tops of the gravel than sinking into it and requiring side knobs to take charge as is the case with most gravel tires.
Doing S-turns through the deeper, looser stuff also filled me with a good deal of confidence. Pushing it hard, I found the point where the combination of turn radius and speed would cause the wheels with these tires to slide out. It was consistent and became predictable
That said, I had to get moving pretty fast before I’d had to come off my line. While you can’t rail the turns with the help of larger shoulder knobs as you can with the WTB Raddler on these kinds of Class 3 or 4 surfaces, I knew and could depend on the Terra Speed’s limits. And those limits were far greater on the Terra Speed than other tires that also don’t have larger shoulder knobs to keep you in the turn.
The Terra Speed’s handling on Class 1 and Class 2 surfaces is solid. It also climbs and accelerates well with no perceptible slip in its grip.
Every tire comes with trade-offs. With the Terra Speed, you give up some comfort and groad-feel, both on par with the average tire in this small knob group but not up to the level of some of the better ones like the Schwalbe G-One Allround or WTB Raddler.
All in, if I’m out for a medium-length ride on mostly paved, Class 1 and 2 surfaces with only a few short Class 3 or 4 sections where speed is my priority, I’ll put the Terra Speed to work for me above any other tire I’ve evaluated.
You buy the Continental Terra Speed at market prices of US$50, £50, €56 by clicking these links to stores I recommend at Planet Cyclery (US/CA residents), Tweeks (UK/EU residents), and other stores I also rate highly through this link in Know’s Shop.
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WTB Raddler – Best Performer Small Knob Tire
The Raddler brings it all together. Even with its short, small knobs running down the tire’s center, it feels like it is rolling nearly as well as a semi-slick gravel tire with no knobs. This keeps you moving both on paved surfaces before and between your gravel sections and on the hard-packed Class 1 dirt and loose dirt and Class 2 spread gravel sections where its knobs give you plenty of grip for straight-ahead rolling and accelerating into and up climbs.
As the gravel gets denser and deeper and the rocks and ruts get larger, I found the Raddler’s larger shoulder knobs kept me tracking in the direction I wanted to go. Climbing, descending, cornering, or doing slalom test turns on these more challenging types of surfaces, those knobs would keep me or bring me back on my line. With most other “small knob” type tires, I had to depend more on my gravel handling skills to control my back wheel slides.
The Raddler’s good grip and handling across a wider range surfaces than most gave this groadie the confidence to charge into corners, attack going up climbs, and not let up going down them. The rubber was comfortable and gave me a good feel for the surface underneath me that closely matched what I was processing with my eyes and brain.
All in, the Raddler’s high performance-level, dependability, and versatility made it a favorite for me. Add in that you can get them with tan sidewalls and that they mount, inflate, and seal relatively easily, and this tire rises to the top of my list of small knob gravel tires for paved, Class 1 and 2 surfaces with the versatility to take on more challenging segments and the comfort to take on the longest of my rides.
At a market price of US$54, £45, €50, you can buy the WTB Raddler at stores I recommend by clicking through these links to Competitive Cyclist, Chain Reaction Cycles, and others at Know’s Shop.
Maxxis Rambler EXO TR
On paved, Class 1, and Class 2 surfaces that are this 38mm Maxxis Rambler EXO TR’s sweet spot, these tires fly with confidence. On more challenging terrain, you can quickly lose control. With these tires more than others, it’s important to know what you are getting into.
You roll with very little resistance on asphalt with the Ramblers underneath you. That feeling continues on Class 1 packed and loose dirt to the point where you feel you are almost cheating the surface. Its roughness is trying to slow you down but you can accelerate, roll, corner and climb with seemingly little resistance and higher than normal speeds.
Grip is very good on these gravel tires when you need it to accelerate, go uphill and corner. You quickly build confidence in what the Ramblers can do for you. While not super supple or providing chart-topping groad feel, they are sufficiently comfortable and responsive at the right pressure for the combination of tire size, wheel inside width, and rider weight on both 25C and 23C wheels.
Outside the Rambler’s natural habitat, your confidence in them can go out the window fast. For me, it happened going down a 7% or so grade in loose, dense gravel. Let’s just say I had to pay a lot of attention to what was going on to avoid washing out. Attempting even big radius turns, my simulation of line changes on a Class 3 rock or Class 4 technical surfaces was skid city and not something I’d want to do at speed.
Fellow tester Miles has ridden the Maxxis Rambler EXO TRs a bunch and has had a lot of success with them on well-maintained dirt roads. On last year’s Vermont Overland, however, he commented that he definitely couldn’t “send it” on the final technical descent with the Ramblers on board. He still finished top-10 which speaks to how well the Ramblers (and Miles) do on a course that’s 85% Class 1 dirt or Class 2 spread gravel.
If you often ride the surfaces that bring out the best in the Ramblers, you can trust these will help you ride along at a good clip. They’re available for US$54, £40, €52, through these links to recommended stores Competitive Cyclist, Tredz, and more at Know’s Shop.
Schwalbe G-One Allround
If you do most of your “gravel” riding on pavement and Class 1 hard-packed dirt surfaces, the Schwalbe G-One Allround Evo Microskin TL Easy tires will give you an “all-world” or best-in-class ride.
Riding them on spread, loose or deep gravel, on soft dirt or sandy roads, surfaces with a lot of visible or partially buried rocks, or those with a lot of washboard or potholes – essentially any Class 2 gravel or above – gives you a more of an “alright” but nothing special experience.
In their sweet spot, the 35mm G-One Allround feel nearly as fast as a slick tire on pavement, as comfortable as a supple 40mm gravel tire inflated 4-5 psi less than I ran these, and as grippy accelerating and climbing as one with knobs 2-3x the pimpled size of those spread down the center and along their shoulders.
They give you an excellent paved and gravel road feel and a high level of confidence in that environment.
Once I moved onto softer dirt and gravel more typical of Class 2 surfaces, my confidence in these Schwalbe G-Ones faded. They slide out when cornering on these and more challenging Class 3 and 4 gravel roads, wobble through looser and deeper gravel and bounce a bit more off embedded rocks than I find comfortable.
As with several other tires in this review, I considered the trade-off of dropping the pressure to a 38mm or 40mm tire level or wondered if I should have tested the 40mm version of the Allround instead. At a lower pressure, I’d likely give up some of their excellent speed on the paved and Class 1 hard-packed dirt surfaces for a little tamer straight ahead ride on more demanding roads.
Without larger shoulder knobs, I don’t know that a lower pressured 35mm Allround or an appropriately inflated 40mm one would do much better cornering on gravel or riding through deeper gravel and dirt sections.
If I’m doing an event or riding a route that is mostly dirt with ample paved sections connecting them – and there are plenty of them especially in the East – I’d reach for the Schwalbe G-One Allround as one of my first choices. If this fits what you ride, you can order a pair for US$33, £30, €34, at recommended stores Merlin Cycles, Tweeks Cycles, and others at Know’s Shop.
Bontrager GR1 Team Issue
The Bontrager GR1 Team Issue rides in its sweet spot competently and won’t surprise you. Riding it on wheelsets ranging from 22.5mm to 25mm inside width, I built a level of understanding and confidence in its strengths and limits.
While it’s available in 35mm and 40mm widths, the 35mm size GR1 Team Issue I rode seemed best suited to its strengths. It grips well on Class 1 dirt and Class 2 gravel surfaces when accelerating, riding the flats, and going uphill. Cornering is confident.
It moves easily across the asphalt and packed dirt, though not as quickly as a semi-slick gravel tire or a few of the better small-knob tires whose design it shares. The 35mm wide GR1 also rolls steadily through deeper, softer dirt and sandy sections.
Confidence going downhill at speed on looser and denser Class 3 and 4 gravel increased when I rode the GR1 on a wider wheelset. What was a manageable wiggle on a 22.5mm or 23mm wide rim disappeared and increased my confidence letting loose on a 25mm wide platform.
So why not go with the 40mm width GR1 Team Issue? And why do they call it “Team Issue”? I can’t answer that second question but I will take a reasoned stab at the first one.
The handling, grip, and resulting confidence are already pretty good with the 35mm size tires. While they didn’t do well on the few Class 3 rock sections I rode them on, because they don’t have larger shoulder knobs I don’t think they are going to do any better with the same design but just a wider tire on the more challenging surface.
A wider 40mm tire inflated at 3-4 psi below the 35mm as would be the recommendation, will only make you slower with its bigger tire patch rolling along the paved and packed dirt sections.
But, if you care more about comfort than speed on a long, more leisurely ride, going wider will make for a more enjoyable time. The 35mm width’s ride is relatively firm even at the recommended pressure on a 25mm wide tire and the “groad feel” is only average.
Taking it all in, the 35mm wide Bontrager GR1 Team Issue provides confident performance on Class 1 and 2 surfaces. You can pick it up for US$65 here on the Bontrager portion of Trek’s site.
Specialized Trigger Pro 2Bliss Ready
After riding the Specialized Trigger Pro a number of times in different situations, I came away with one overriding impression – solid citizen. Nothing flashy, nothing objectionable. Wouldn’t be my first choice but would be fine having them join me on a none-to-challenging endeavor on dirt and gravel.
These tires certainly make a good first impression. They mounted up easily without tire irons on the range of rims I tried them on and usually inflated with a track pump. Sealing was a one-and-done experience and, when it was time to remove them, they came off rims with thumb pressure alone.
While the Trigger Pro’s center tread knobs are shorter and smaller than those that run out to the tire shoulders, they make up a narrow strip. The larger knobs on either side of them are also in contact with the riding surface when the wheels are fully upright going straight.
That design seems to create a fair amount of resistance on paved and hard-packed Class 1 dirt roads. To use another analogy, riding them on these surfaces feels akin to rolling on fine sandpaper in the 120-220 grit range.
The Trigger Pros provide plenty of grip for accelerating on the flats and going uphill. When you need to brake, they are right there to help you execute without sliding.
Riding them through looser dirt and mud-caked surfaces tended to hold me back. Turning or changing lines through more concentrated gravel patches or doing slalom test turns tended to create a bit of hip-swiveling. Controllable, predictable yes but not precise or fast.
Like a solid citizen, you are confident in what you are riding with the Trigger Pro mounted to your wheels. They aren’t as versatile as some and you won’t ride the fastest with them rolling underneath you but you can depend on them coming through.
Selling for US$50, you can buy the Trigger Pro at Competitive Cyclist.
Kenda Alluvium Pro
While better on some gravel roads than others, the Kenda Alluvium Pro doesn’t ever let you down.
It feels fast on paved surfaces and keeps you moving well on Class 1 hardpack and softer dirt. There’s plenty of grip navigating across the flats, in turns, going up and down these surfaces.
As you get onto the spread gravel of Class 2 roads and the more challenging looser and deeper gravel, dirt, rocks, and technical Class 3 and 4 sections, the Alluvium Pro hangs in there but doesn’t excel.
You don’t slide but can’t hold your line at speed through gravelly corners. You twist through deeper, looser dirt, gravel, and rocks going downhill but don’t ever washout. Whether at or a few psi below recommended pressure, it’s not uncomfortable but not a compliant ride either.
In addition to the 35mm model shown here, I also tested the 40mm version. The latter measures a good deal wider (44mm wide on 25C rim at 30 psi) and heavier (488g/tire) and negotiates Class 2 surfaces a bit more confidently. As with the 35mm, the 40mm Alluvium Pro creates a rear-end wiggle at speed through deeper and looser dirt and gravel.
If you don’t demand the highest level of performance but want one tire that can get you almost anywhere at a price typically around US$60 you can order the Alluvium Pro at recommended stores JensonUSA and Amazon.
Panaracer Gravel King SK
The Panaracer Gravel King SK tubeless tires were a fail or meh for me on nearly every measure. They were a lot of unnecessary work to set up the first time and performed like wooden shoes on the very standard terrain and good wheels I rode them on.
The walls of the 35mm wide labeled tires I tested were paper thin. While that may contribute to their being 50 to 100 grams lighter per tire than others of the same width, it also meant they wouldn’t stand on their own enough to spread outside the wheel’s center channel even with the force of an air compressor. To eliminate the possibility of the Gravel King and wheelset just not playing well together, I tried them on 3 different wheelsets with no luck.
Pumping these GravelKing SKs with a tube pushed the sidewalls out to the edge of the rim bed. I had to inflate them right up to their 5 bar/75 psi max pressure to get the tires to ping into the bead locks, that narrow channel on either edge of the rim bed. That’s higher than I can ever remember needing to inflate another tubeless tire and, clearly, higher than you ever want to run them with the hookless rims that most modern gravel wheels use.
To run these Panaracers tubeless, I then removed the tubes while maintaining tire contact with one rim wall, needed a compressor to inflate the tires against the other side, deflated, poured in the sealant through the valve, and inflated once again.
What we will do for our weight weenie obsession!
Fortunately, once the Gravel Kings were mounted and ridden a few laps, they must have reshaped somehow. I didn’t need to use a tube to inflate them on the next sets of wheels for additional testing but still needed a compressor with the valve core removed to get them to seat into the bead locks.
Whatever hoped for lightweight benefit there might be didn’t materialize in the tire’s actual performance. The moderately-sized square block center tread suggests these are not intended for paved or Class 1 hard pack dirt surfaces. My experience bears that out. They felt leaden and very slow.
Unfortunately, the ride got worse on Class 2 gravel and softer dirt that I’d thought would be their sweet spot. The tires didn’t feel very supple in hand and on these surfaces, and not surprisingly there wasn’t much groad feel. While they accelerated and stopped well, in between they ping-ponged around through consistent gravel and were really wild in the deeper stuff.
Since the GravelKing SK tires enjoy “rock star” status in the gravel tire world, I was as surprised to find this poor level of performance in my testing as you probably are reading about it. To see if I was missing out on something, I tried them at different pressures on both alloy and carbon wheels of different inside rim widths but couldn’t find a combination that allowed them to deliver a great performance. I didn’t feel confident going through corners at top speed, they didn’t track through softer dirt, sand or deep gravel with any certainty, and it was a thrill a minute just going downhill through standard Class 2 gravel.
I couldn’t imagine riding them on Class 3 larger, variable shaped gravel, partially exposed rocks, and tire trenches unless I wanted to play the role of a bucking bronco rider.
Perhaps I had the wrong width. Panaracer sells the 700c version of these tires in 32mm through 50mm widths. These 35mm ones actually measured between 37mm to 38mm depending on rim size and tire pressure. So they are in the same size neighborhood as others in the “small knob” category I compared them to for this review.
Or perhaps I had them over-inflated. At between 30 and 32 psi depending on whether I had them mounted on the 25C alloy or 23C carbon wheelset, I was inflating them at the recommended pressure for the combination of their actual tire width, the rim sizes and my body weight (145-150lbs) to the same pressure as other tires in this category of similar actual width.
In search of more comfort and better overall performance from these tires, I tried them at 26 and 28 psi. While only a few pounds of pressure different, reducing the pressure 2 to 6 psi on a gravel tire is a big drop.
At around that pressure, I did find comfort but no better performance. They were slow on paved and hard-pack dirt surfaces. Undoubtedly higher rolling resistance at lower pressure but perhaps fewer impedance losses from my bike and body bouncing around? Yet, even at this more comfortable level, they felt sluggish in the softer dirt, swam left and right through deeper gravel, skidded rather than carved turns, and were unpredictable going downhill on anything other than consistent, hard-pack surfaces.
While once well-regarded, in my comparative testing the GravelKing SKs didn’t perform well against today’s gravel tires.
They sell for a market price of US$40, £33, €38, and are available from stores I recommend by clicking through these links to Competitive Cyclist, Merlin Cycles, Tredz, and others at Know’s Shop.
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In upcoming posts, I’ll review Semi-Slick and Big Knob tires. You’ll also see reviews of carbon and alloy gravel wheels later this summer.
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Enjoy your rides safely, both on the road and gravel!
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First published on June 27, 2020. Date of the most recent major update shown at the top of the post.
