Gravel grinders, all-road or adventure bikes—whatever you call them, we put five of the best to test. Iain Treloar reports.
Picture this: you’re on your road bike, powering along the tarmac, when out of the corner of your eye, you spot an unpaved road that you’ve never really noticed before. It’s sun dappled and alluring, curving gently uphill through the trees, a dusty haze from the gravel hanging in the air. You wonder where it goes, imagining the possibilities that lie in wait down the way. Then you look at your skinny tyres, and remember you’re on your road bike.
Oh well. Plenty more boring bitumen to ride.
But what if it didn’t have to be that way? What if there was a style of bike that didn’t compromise in on-road function, but gave you the confidence to take that dirt detour or dive down that singletrack? What if, in short, there was that elusive one bike that could do it all?
For a while, it seemed like a cyclocross bike was this solution. It’s actually pretty close, offering clearance for some knobblies, more robust construction and, nowadays, disc brakes. However, the format of cyclocross racing—flat-out, hour-long races—betrays the limitation of the ‘cross bike. With a low front-end and steep angles, it’s too quick-handling and aggressive to be an ideal all-day adventurer.
A new category has since developed, described variously as ‘adventure road bikes’, ‘gravel bikes/gravel grinders’, ‘all-road bikes’ or ‘new-road’, depending on which marketing department’s doing the selling. I like the first one best.
This new category has met with some skepticism, cited as evidence of the escalating segmentation of what was, just a decade ago, simply a ‘road bike’. But having spent some time with five of the most exciting examples of this new style, I’m sold. The marketing and description of these bikes may imply that they’re the nichest of the niche—after all, as a percentage, how much time do you spend on gravel, really?—but that’s just one way of looking at it. If you want a narrowly-focused bike that’s perfect for its task and that alone, one of these is probably some way down your shopping list. But if you want one bike to do it all, this might just be it.
So, what defines this category? Depending on a manufacturer’s interpretation, that’s actually a pretty fluid thing, but a general catch-all would go something like this—“the all-surface adaptability of a cyclocross bike but with the comfort of an endurance road bike, with disc brakes and clearance for wider tyres.” Or, put another way, a sensible bike that does a lot of things pretty well, can take a knock or two, and widens your horizons for exploration and fun. You’re right—that does sound awesome. Let’s go.
Cannondale Slate Ultegra
Outrageously fun and kooky
RRP: $3,999 / Distributor: monzaimports.com.au
It’s hard to think of a recent bike that’s created a bigger stir than the Cannondale Slate, which flips conventional wisdom of road bike design on its head and makes a mockery of easy categorisation. It loosely takes design cues from the brand’s CAAD12 and Synapse, but skews them so thoroughly as to be almost unrecognisable. It’s a road bike, sort of, but with smaller wheels (650B instead of 700C). And it has front suspension, in the form of the super trick Lefty Oliver.
All of this makes it an extreme outlier in the category—a category to which Cannondale don’t really subscribe in the first place. For them, the Slate is designed from a road perspective, but it’s also neither road bike, cross bike or mountain bike, but some sort of blend of all of these. It’s a do it all, ride it anywhere, kind of machine, and there’s something wonderful about the uncapped potential in that.
The theory behind tyre width and pressure has gone through some changes over recent years. For decades, the prevailing wisdom was that skinny tyres at high pressures was the benchmark. However, developments in tubeless tyre technology, learnings from the mountain bike world and increased scientific rigour has meant that wider tyres at lower pressures are now accepted as the way to go. The benefits, in a nutshell, are better grip, greater comfort, and often—counterintuitively—reduced rolling resistance.
That said, there’s quite a mental leap from a 700x25C to a 650Bx42C, which is what the Slate comes equipped with. The tyre is broad and tall to the eye, but actually equates to the same outside diameter as a 700x23C; roll-out is the same but with the ability to run it all at far, far lower pressures (as in, 40PSI).
There’s inherent suspension in large volume tyres at low pressures, but the Slate adds even more in the form of actual suspension. Cannondale is not new to suspended road bikes, with the Headshok-equipped Silk Road turning heads at the cobbled-classics at the turn of the century. The Slate advances this thinking with a more aggressive geometry more closely rooted in the brand’s elite road bikes—rather than forcing a higher stack height—by speccing a Lefty Oliver – a 30mm-travel, single-sided set-up on the front. This looks kooky but performs surprisingly well in a range of terrains. The lockout works as it should—a release valve stops it imploding if it takes a big hit when locked out—and the fork is helpfully marked for suspension-unsavvy roadies with ‘Push to climb’ and ‘Push to descend’.
When radical changes are made to bike design, there’s inevitably a period where preconceptions about consumer response to the bike are either supported, or rejected. The Slate is—to be clear—marketed by Cannondale as a road bike, but that does a disservice to its extraordinary capability off-road, even in rough singletrack—great capability not just for a road bike, but full stop. In fact, I had the most fun on this bike when I had it set up with low pressures in the tyres and the suspension open, off-road. The Slate’s on-road performance lacked a little spice for my liking; the bike takes the sting from the malaise of even the roughest commute, but sacrifices a certain immediacy, and you’ll be slightly but crucially off the pace in an on-road bunch. Whether this forces a recalibration of the Slate’s recommended target terrain remains to be seen.
I’m not entirely convinced of the durability of the tyres supplied—they’re a slick made for Cannondale by Panaracer—and they were a bit prone to sudden loss of traction when pushing corners off-road. A secondary concern is the limited availability of options for tyres and tubes—your riding buddies won’t be able to come to your rescue with loaner tubes for this one. 650B (aka 27.5”) is emerging as the dominant wheel size in mountain bikes, but the reduced tyre clearance on the Slate’s chainstays rules most of those wider tyre and tube options out. A couple of smaller tyre brands like Surly and larger ones like Schwalbe have branched out into 650B gravel-appropriate tyres, which improves the offering somewhat, but it’s still, inescapably, a little niche. (For what it’s worth, if you cop a puncture, I found a skinny 26” tube will get you out of trouble).
The Slate is a bold machine, and Cannondale should be commended for some serious outside-the-box thinking. Is it perfect? No, far from it, but it’s ridiculously fun and incredibly desirable, and I really, really want one.
Specialized Diverge Pro Carbon
Smooth and capable, with excellent on-road chops
RRP: $6,599 / Distributor: specialized.com/en-au
The Diverge was one of the mainstream originators of this style, using the brand’s popular endurance road model, the Roubaix, as a starting point, before the incorporation of tweaked geometry, greater tyre clearance and a few other tricks. Specialized have a wide range of bikes, and the Diverge is no exception—in Australia, there are seven models to choose from, split into two entry-level aluminium bikes (from $1,399), two higher-end aluminium models (from $2,099), and three carbon-framed models ($4,199–$6,599). Our test model, the range-topping Diverge Pro Carbon, features mechanical Dura Ace gearing, a carbon clincher wheelset and Specialized’s own carbon crankset, weighing in as lightest on test at 8.13kg (56cm).
Compared to others of its ilk, Specialized’s interpretation of the gravel bike is reasonably conservative, and road-based—with a close visual similarity to the Roubaix, it also looks the most traditionally road-bikey of the bunch on test. This holds true in its riding characteristics, with little discernible handicap in speed on paved surfaces.
The Diverge employs a few of Specialized’s better-known vibration-dampening techniques. The most obvious of these is the Zertz inserts on the fork and the seatstays—these are, according to Specialized, ‘viscoelastic dampers’ designed to absorb high frequency vibrations from the road. It’s difficult to judge exactly how much of the frame’s comfort is tied to their inclusion—it’s reasonable to assume that tyre pressure, width and carbon layup has more to do with it than a plastic widget—but regardless, the Diverge offers decent comfort on rough roads, only getting overwhelmed through the front end with big hits.
Specialized are clever enough to add things like gel padding beneath the bar tape, further heightening the perception of plushness. While I’ve ridden more comfortable bikes in my time, the Diverge is certainly within the top third. It’s handling, meanwhile, is among the best. With a relatively long wheelbase and a low bottom bracket, it positively carves through fast corners, is well-mannered in more sedate conditions and climbs well. The handling of many, many pure road bikes pales in comparison to the Diverge, and with its added versatility it’s truly a force to be reckoned with.
Compliance through the back end is aided by the CG-R seatpost—a model that was previously, regrettably, stylised as the ‘CobL GobL-R’ (say it out loud, groan). This seatpost, with its unusual kink, gives a claimed 18mm of vertical compliance, which comes in handy on heavily rutted gravel roads. The narrow seatpost diameter (27.2mm) and deeply sloping top-tube (exposing plenty of post) helps here too.
Specialized are a big, influential brand who know that they are both of those things, and they have enough clout that they can introduce proprietary standards, limiting compatibility with aftermarket products. One of their more well-publicised missteps was partially to do with the Diverge; in a quest to keep the chainstays short and retain a tight wheelbase, Specialized introduced a new hub spacing at the rear to preserve correct chainlines. The inadvertent side effect of this was to restrict consumers to Specialized’s own wheels—something that quite understandably put a lot of people offside, given the strong preferences many road riders have about their wheelsets. For the models below this one, which sport a heavier and less elegant alloy wheelset, that’s certainly a valid concern, but the top-end model’s excellent carbon Roval Control offering is good enough to appease any anxiety.
Specialized have made much of the versatility of the Diverge in their marketing. To a certain extent, they’re justified in this; they’re not just paying lip service to the category, incorporating mounting points for mudguards throughout; you can even run mid-fork rack mounts. There’s also tyre clearance up to 700x35C, although it’s supplied with Specialized Roubaix Pro 25/28C tyres—not drastically different to what you’d put on a pure road bike. Some riders will find this tyre clearance inadequate, but it’s pretty spot-on for the Diverge’s target demographic.
As you’ll see in this test, any example of the gravel bike category skews depending on the interpretation of the designer. The Diverge, in essence, is a comfy carbon road bike with big tyre clearance, a model that hedges some bets and assumes that there are plenty of riders that will spend a majority of their time on road, with a smaller proportion of time on gravel. That, I suspect, is a pretty wise assumption on the part of Specialized—if I was in the market myself, a bike to cater for a 90% road/10% off-road split is what I’d be looking for. The Diverge is the most democratic of the selection here and suits a wide variety of prospective buyers pretty well. If you’re in the market for a disc-brake road bike (as opposed to just an adventure road bike) this is an outstanding contender as well, offering performance, comfort and versatility, without eschewing the best of modern materials and technological advances.
Niner RLT 9 Steel
Amazingly versatile with beautiful geometry
RRP: $2,390 (frame, fork, headset), $4,690 (as pictured) / Distributor: rowneysports.com, or call 1300 938 469
One of the many interesting things about the gravel bike category is that it can entice mountain bike specialist brands to broaden their horizons. Niner—an American brand whose bread and butter is 29” mountain bikes—offers up the intriguingly versatile RLT 9 (that acronym stands for ‘Road Less Travelled’). This frame is available in alloy ($1,690) or steel ($2,390) variants, both supplied with a carbon fork. We tested the more-ritzy of the two, constructed from Reynold’s highly regarded 853 tubing.
This is a bike of broad ambition and appealing utility, offering capacious tyre clearance and an abundance of mounting points for touring and bikepacking purposes. On the other bikes reviewed in this test, we’ve seen brands offer up clearly-defined interpretations of a style, but the Niner is something of a blank slate in comparison. If you want a rigid drop-handlebar mountain bike, that’s possible (you can fit up to 29×1.75” tyres, depending on the model). If you want a touring bike, great—there’s mounting points all over, and if that’s not enough, mount a frame-bag in your front triangle and there’s still a third bottle-cage mount hiding away underneath the downtube. If you want a road bike, spec it with narrow tyres (on our test wheelset, down to 25C) and road gearing. Options for drivetrains are suitably catered for, from single-speed to triple chainring cranksets all the way up to Di2. You can slice and dice it in all sorts of ways, and it promises to be pretty capable no matter which you opt for.
Our test model came built up with SRAM’s Force 22 groupset, and Avid BB7 Road mechanical disc brakes. SRAM’s gearing makes me happy—all positive engagement and clearly defined shift points—but the mechanical disc brakes confirmed the superiority of hydraulic braking. That, however, is the freedom you get from buying a frame from a brand like Niner instead of a complete bike from a major manufacturer; you can build it up to your personal preference, and create something that perfectly suits your needs. And if we’re learning one thing from this article, it’s that your needs of a bike within this category may be very different from someone else’s.
Our review model came equipped with a massive 700x40C WTB Nano tyre, which gave pretty much everything you could reasonably wish for off-road, with clearance to spare. Personally, for the breakdown of my riding, it was a little too much tyre; the extra rolling resistance was easily discernible on the commute, but proved a benefit off-road, which was where the RLT really came into its own. On rougher surfaces the stability of this bike was truly impressive, inspiring confidence with its handling and grip. In terms of positioning, the RLT felt sporty but comfortable. This model has had an interesting genesis, originally positioned by the brand as a cyclocross bike. It’s evolved since its first iteration, most recently adding thru-axles front and rear and mid-fork rack mounts to bolster its versatility. One hangover from the early days of the RLT, however, is a relatively high bottom bracket. Personally, I’d have liked a little bit more BB drop to feel more ‘in’ the bike, but that’s a minor complaint on a machine that rides beautifully and offers almost limitless potential for personalisation.
Thanks to Summit Cycles, Fitzroy for their help with this build.
Curve Grovel CXR
Exotic and elegant, with a lively personality
RRP: $2,599 (frame), $549 (fork), ~$8,999 (as pictured) / Distributor: curvecycling.com.au
Curve is a Melbourne-based brand that first made a splash with their carbon wheelsets. Their inventory is steadily expanding, and they now offer a small selection of frames, for the most part constructed from titanium. An interesting part of Curve’s story is the exhaustive development and testing that goes into their products. Jesse Carlsson, one of the brand’s co-founders, won the inconceivably tough Trans Am race last year on a Curve. If a frame, fork or wheelset can survive 6,700km in less than 20 days, you know it’s well-built.
The Grovel CXR is a modified version of the cheaper Grovel 4130—slightly more aggressive in its geometry, titanium, and thru-axle equipped. The frame was originally envisaged as a pure cyclocross race platform, but Curve have found that many of their customers are using it as more of an all-rounder instead; our review bike came to us fresh off a 600km tour of the west coast of Tassie. There aren’t mounting points for racks, so frame bags rather than panniers are the go, but the frame’s more than sturdy enough to take a load.
Curve’s frames are consciously designed for ease of maintenance and assembly; on the Grovel CXR things are pretty trouble-free mechanically, with a threaded bottom bracket and external cabling. This, routed along the top tube, is a clean and enclosed solution, but with the minor downside that the cable ties holding the cables in place tend to catch on your knicks when you’re off the seat (at traffic lights, for instance). There are thru-axles front and rear, with a carbon fork (also by Curve) finishing the frameset. Clearance is decent but not as generous as on the Niner RLT—the fork’s clearance maxes out at 38C.
This bike has an impressive liveliness and excitement to its character, accelerating quickly and proving comfortable on longer road rides and through chopped-up gravel. It’s improved by its near flawless build–there is not a single thing hanging off this bike that I would change, with the possible exception of a double chainring set-up. Of course, you have the freedom to build one of these frames up however you prefer, which although probably more expensive than buying a complete bike, offers much more in the way of reward. For what it’s worth, though, the Enve and Chris King bits and bobs on this bike were both elegant and functional (and the buzz of that rear hub sounds amazing). SRAM’s Force 1X groupset rounded the package out, with a wide-range (10-42t) cassette taking almost every gradient in its stride.
As a frame-building material, titanium has a number of satisfying properties—it’s durable, highly corrosion-resistant, pretty light and beautiful. Curve’s meticulously finished frames are built in China to stock geometries, and—compared to most other titanium brands—are competitively priced. When such a frame is paired with an impeccably curated, detail-oriented build such as this one, it makes for a gem of a bike.
Thanks to Jetnikoff Bicycle Co. for the loan and build of this bike.
GT Grade Alloy X
A highly capable all-rounder
RRP: $2,399 / Distributor: monzaimports.com.au
Over recent years, GT has had patchy luck, at best, cracking the road market. In the immediate past they’ve focused their attentions ever more closely on their well-regarded mountain bike range. All of this made the appearance of the GT Grade two seasons ago something of a pleasant surprise. The fact that it was among the best reviewed bikes of 2014 was, then, even more surprising, but there it was—the Grade, along with the Specialized Diverge, was one of the most important mainstream originators in this new category.
It took a while for the Grade to make it to Australia, and demand has since outstripped supply; the unanimously well-regarded carbon framed version is out of stock until the next season lands around September 2016. We reviewed the GT Grade Alloy X, a model based around SRAM’s Rival 1x drivetrain. SRAM have gotten huge market traction in the cyclocross and gravel categories with their 1x setups, which run a single chainring and a clutch rear derailleur to minimise the likelihood of dropping the chain. In theory, it’s a great solution, eliminating redundancies in gear combinations compared to a double chainring, saving a bit of weight and cutting down on maintenance.
Key to the success of any 1x setup is careful selection of the gear ratios on the bike. I’m not sure GT have got it quite right on the Grade. It’s specced with an 11–28t cassette which gives close spacing, but is a bit limiting off-road. The rear derailleur is capable of accommodating up to a 36t at the back, an option which would provide handy climbing capability.
With a long wheelbase and low bottom bracket, the Grade feels planted on a range of terrains and offers an accessible, endurance-oriented ride. Flexible riders used to an aggressive position may find it difficult to get the front end low enough—the Grade’s stack height is the tallest of our test fleet, and feels it. Our large/56cm sample came with an unusually long stem for the size (120mm), but I quickly swapped it out for a 100mm giving a more comfortable reach, and adding a little litheness to the handling. Component selection throughout is otherwise well-considered, in particular the tyres. These are the 700x33C Clement MXP, a cyclocross tyre that rolls surprisingly quickly on paved surfaces paired with impressive grip off-road. There’s room for wider tyres—35C at least, and I reckon in some brands you could squeeze a 38C in.
The bike’s appearance is a little polarising. I’m not greatly enamoured with the teal, and the welding around the bottom bracket is functional rather than attractive. It also dates itself a little with its mix of thru-axles at the front and quick release at the rear—the latter is functionally fine, but an odd disparity. But even if this bike isn’t necessarily winning any beauty pageants, it’s impossible not to admire what GT have achieved with it. The geometry and ride is sorted, and it’s a great platform to finetune into the bike best suited for your needs.
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