Wil Reviews The Curve DownRock
In case you hadn’t noticed, hardtails have been enjoying a bit of a renaissance of late. Sure, full suspension bikes are a lot easier to live with these days, having gotten significantly smoother and more capable over the past decade. But so too have hardtails. They’ve just been going about their business a little more quietly.
The same technological improvements and forward-thinking geometry we’ve seen championed in the trail and enduro world have also been made available to bikes without rear shocks. Slack head angles, long reaches, larger wheels, wider tyres, short stems, wide bars, long-stroke dropper posts – these are tools that have become commonplace on full suspension bikes these days. But you’ll also find them on the humble hardtail too, where I’d argue that they’ve made an even bigger impact on the overall ride quality, and capability, compared to their fully suspended cousins.
Watch the video review on the Curve DownRock here:
- 0:20 – Intro
- 0:57 – Curve Cycling
- 1:19 – Frame Material & Construction
- 3:11 – Scaled Rear Centre
- 3:56 – Frame Sizing & Geometry
- 4:57 – Pricing & Build Options
- 6:01 – Bike Setup
- 8:06 – Complete Bike Weight
- 8:20 – Strengths
- 10:59 – Weaknesses
- 12:46 – Component Notes
- 13:20 – The Verdict
For the past two months, I’ve been riding one of these new-school non-rear-shocked bikes. It’s called the DownRock, and it’s a fresh titanium mountain bike from Melbourne-based brand, Curve Cycling. Unlike most titanium hardtails on the market though, this is no bikepacking rig or XC racer.
Designed to accommodate a 130-150mm travel fork, 29in wheels and tyres up to 2.6in wide, the DownRock is 100% made to party. Curve calls it “our interpretation of the modern trail hardtail. A balanced, versatile mountain bike for fanging around like a frill neck lizard on hot sand“. Colour me intrigued.
At first I thought the DownRock was an odd model to have come from a brand that’s best known for its involvement in the road, gravel and bikepacking markets. As it turns out, mountain biking already runs strong through Curve’s DNA though, with the small company having actually started out producing carbon mountain bike wheels. Steve Varga and Liam Carmody of Curve Cycling are both passionate mountain bikers born out of the Melbourne riding scene, and from day one, they’ve been key proponents behind the progression of the brand’s dirtier offerings.
In terms of its off-road range, Curve currently has a couple of curly-bar bikes (the GXR and GMX), as well as an XC hardtail called the UpRock. Adding to that range is the raked-out ripper we have here.
With two years of development and prototyping behind it, the DownRock has been quite the passionate project for Carmody – Curve’s lead mechanical engineer and product designer. A huge amount of time and resources have gone into developing the DownRock’s overall shape, with the geometry being something that Carmody has agonised over in obsessive detail.
His goal? To create a hardtail that isn’t just brawny and stable enough to keep up with modern full sussers at high speed, but one that’s still fun and involving to ride too.
What Makes It Special?
Like all of Curve’s frames, the DownRock is manufactured from 3Al-2.5V Titanium tubing. Why Ti? Well as far as metals go, titanium has the highest strength-to-weight ratio of all of them, and it’s about 40% lighter than steel. It also possesses the ability to make your wallet a lot lighter too.
However, it is corrosion resistant, and it’s more resistant to fatigue than alloy, which makes it a halo choice for riders who want a tough, durable and long-lasting frame. It isn’t the easiest thing to work with though – you’ll need an inert gas like argon in order to protect it from contamination with the air, which has the potential to reduce the integrity of the welds.
Welding doesn’t appear to be a problem here though. The frame itself is beautifully finished to an exceptionally high standard, with a shapely zero-stack headtube, cowled dropouts, and post mount tabs for the rear brake that requires no adapter with a 180mm rotor. This is one seriously good looking bicycle.
At the centre of the frame is a huge T47 bottom bracket shell, which is basically a threaded version of a PF30 bottom bracket. With the appropriate thread-in bearing cups, it’s designed to accommodate pretty much any crank on the market, while also allowing for greater surface area for where the chainstays, seat tube and downtube meet in this high-load junction point of the frame. Something that’s particularly important for the larger frame sizes, where the top and downtubes are particularly long.
Combined with the the 3mm Boost offset and the solid titanium plates used to engineer the complex chainstay yoke, there’s clearance for up to a 2.6in tyre in the rear. Even more impressive is that Carmody has been able to achieve that clearance while maintaining a very compact rear centre length.
Ahead Of The Curve
One of the key elements behind the geometry on the DownRock is the scaled rear centre sizing, which sees the chainstay length ranging from 420mm to 445mm long. The concept is simple. To maintain consistent weight distribution between the front and rear wheels, the smaller frames get shorter rear ends, and the bigger frames get longer rear ends. And it makes total sense. After all, if a larger size gets a longer reach, why shouldn’t it get a longer rear centre too?
I should point out that what Curve is doing with the DownRock isn’t a totally unique concept. Brands like Mondraker and Santa Cruz offer certain models with dropout flip-chips, and Norco has been building its full suspension bikes with specific rear centre lengths for quite some time. It still isn’t common though, and that’s largely down to manufacturing costs. The more tubes (or moulds) you can share between sizes, the cheaper the frames are to produce.
Having a unique back end on each of the DownRock frames is inherently more expensive than keeping the rear centre the same length throughout, but Carmody feels strongly enough about keeping that front-centre-to-rear-centre ratio as consistent as possible, that he convinced the wider Curve team to commit to the investment.
While we’re on frame sizes, there are actually five, and not four like you’ll find with most brands. Carmody has squeezed an ‘Extra Medium’ into the middle of the range, which affords another choice for riders in the 175-185cm height bracket. Again, this adds further expense to the manufacturing process, but it also ensures there are smaller gradients between each size. With less compromise on fit, and short seat tubes spec’d on every size, riders have more flexibility to choose based on their preferred reach measurement.
Frame reach is roomy, but not quite as uber-long as some others. The DownRock gets a slack 65° head angle, and a steep 75.75° effective seat tube angle. That last number has actually been slackened off from the original prototype in order to increase the effective top tube length – something I’ll get onto in a bit.
What’s It Wearing?
Curve offers the DownRock in three different configurations. You can get the DownRock as a standalone frame that sells for $3,399 with the headset, seat clamp, axle and cable gubbins included.
There’s also a complete bike, which is what we’ve got on test here. This single spec option is built with Curve’s own carbon Dirt Hoops, a SRAM GX Eagle 1×12 drivetrain and G2 RSC brakes (check out the complete specs below). At $8,699 though, it isn’t what I’d consider great value. It’s a huge sum of money for a bike without a rear shock, let alone one spec’d with a mid-level drivetrain. You could buy a carbon Stumpjumper for less! Even Norco’s top-end Optic C1, which gets an X01 drivetrain, a carbon mainframe, and a rear shock, sells for nearly two thousand dollars less than the complete DownRock.
What is a better value proposition however, is the frameset package, which sells for $4,499. Along with the frame, you’ll get a RockShox Pike Ultimate fork and the new generation Reverb C1 Stealth dropper post – two items that are worth over $2,000 on their own. If you went down that route, that would still leave you $4,200 to buy whatever wheels, groupset and cockpit you fancy.
Let’s Talk About Setup
At 175cm tall, I could potentially choose between a Medium or Extra Medium frame size. I went with Medium, since my stumpy legs would have presented a problem in trying to to accomodate the longer seat tube and the 175mm dropper. With the Medium, I’m pretty close to having the Reverb’s collar slammed onto the seat clamp, which is ideal.
Reach sits at 444mm, which works great for me, and that’s paired to 800mm wide riser bars and an itty bitty stem. Carmody has designed each frame size around the same 35mm stem length and a reduced-offset fork, so the steering dynamic is consistent whether you’re on a Small or Extra Large. For those who want a closer look at the DownRock’s frame geometry, check out our detailed first look story here.
Being a hardtail, tyre choice and pressures are absolutely crucial to comfort, traction and the overall riding experience. While I didn’t have any problems with the stock e*thirteen tyres, I was looking for a little more compliance, particularly with the stiff carbon wheels. I decided to swap them for a set of higher volume 2.6in wide Bontrager XR4 Team Issues, which are well-damped and highly versatile tyres that recently snuck into my Top 10 list of bikes and gear from 2019.
As well as providing more cushion, I wanted to see how much clearance there’d be in the back of the frame with the biggest tyre you can officially put in there. The answer is ‘not heaps, but enough‘. The one muddy ride the average Aussie mountain biker goes on each year is likely to see things pack up pretty quickly, but aside from that you’ll be fine. I didn’t experience any untoward rubbing or clearance issues throughout testing.
I did fit a Vittoria Air-Liner tubeless insert to the rear wheel partway through though, which allowed me to drop pressures down further – I ended up at 20psi on the rear and 18psi on the front. As well as providing protection for the expensive carbon rims, the Air-Liner also improves compliance and adds a degree of damping control to the big 2.6in tyre, something that is quite noticeable on a hardtail. It does add weight though – 293g for the ‘L’ size I fitted.
Up front, Curve has spec’d the RC2 version of the Pike Ultimate fork. That means you miss out on the lockout and 3-position compression dial, but you do get separately adjustable high and low-speed compression damping. As per the setup guide, I ran 82psi to support my 68kg riding weight, with two Bottomless Tokens inside the DebonAir spring. I ran the rebound one click slower than halfway (8/18 clicks), and the high-speed compression one click off the softest setting (1/4).
Being a hardtail, keeping the fork riding higher in its travel will help to preserve the head angle on the descents. As such, I set the low-speed compression dial on the firmer side between 9-12 clicks out of the 18 available.
What Does It Do Well?
My first few rides aboard the DownRock proved to be a bit of a rude awakening back into the world of rigid frames. Without a rear shock isolating you from the trail, your contact points have a more direct line of communication with the terrain, which is both a good and a bad thing. Either way, it takes a bit of time to recalibrate your riding style.
The big volume rubber goes a long way to absorbing smaller vibrations, and shoe choice also has a significant effect on overall riding comfort. Stiff carbon XC toe-tappers will transmit more force through to your feet, so I favoured either flats or thicker gravity-style SPD shoes to provide a bit more cushion.
Even still, you’re presented with a tonne of feedback from the trail, and that requires a different technique with a more considered approach to line choices. It also requires you to employ the best suspension mother nature gave you – your arms and legs. The 175mm stroke dropper post is an absolute boon from this perspective. Combined with the low slung frame and wide bars, the DownRock gives off a total BMX vibe when its set to party mode. Crush the saddle right out of the way, bend your knees and elbows, and you’ve got plenty of room to let the bike dance around underneath you.
When you’re on the gas, there’s solid power transfer through the big BB junction and stiff back end. The chainstays are short on the Medium frame at 424mm, and the BB also hangs very low at 66mm below the hub axle line. This sees the rear tyre tucked in right up against the crankset, with your centre of gravity hovering low to the ground. Without any suspension pivots or shock bushings to disrupt things, there’s a very direct connection between your contact points and the rear axle. This gives the DownRock’s chassis a tight and responsive feel.
Cornering is a delight on this bike. In fact, it might just be one of the best cornering mountain bikes I’ve ever ridden, especially when things get tight.
You do need to lean it quite hard though. The slack head angle and reduced offset fork result in more trail compared to a bike with a steeper head angle and 51mm fork offset, so turning the bars won’t get you around corners particularly well. Instead, you have to lean the whole bike over more aggressively to get it through each bend in the trail. The low BB and wide bars make this an easy task though, and once I’d gained trust in the amount of traction that was on tap, I discovered just how hard you can throw this bike around with its addictive dip ‘n’ rip cornering style. If you’re looking to hone your bar-drags, this would be an ideal tool for the job.
As well as slicing and dicing corners, the tight rear end makes the DownRock willing to pop up onto the back wheel, and it’ll encourage you to do so at every opportunity possible. The agile handling also makes it an easy bike to place on the trail, giving it a zingy and thoroughly engaging ride quality that no full suspension bike can possibly match.
Despite its cheeky attitude through the tight and twisty stuff, the DownRock manages to barrel along at speed remarkably well for a hardtail. The long and slack front end helps in this regard, both by adding stability and by encouraging you to ride further over the front wheel. With more of your weight driving into the front tyre, the back end is able to skip around more freely.
The Pike also deserves credit here for inspiring confidence on the front of the DownRock. The control from the RC2 damper is exceptional, and while there’s only 130mm of travel, RockShox has ensured that it’s a very effective 130mm. There’s excellent sensitivity all the way through, and it takes rapid, violent impacts like a champ.
Riding around the granite-laced trails of the Harcourt MTB Park, I was consistently surprised at how well the DownRock handled the hits. The 2.6in tyres helped to maximise traction and support where possible, rounding off square edges nicely. They add crucial comfort, without the excessive drag and vague handling of full plus-width tyres.
Having the tubeless insert in the rear wheel also meant I could more confidently attack the trail without fear of a ride-ruining pinch flat. Find your flow, and the DownRock rumbles along remarkably well at speed. And the faster you push it, the easier it glides and skips over the rough.
But while it is impressively smooth for a bike without a rear shock, in my experience, it isn’t quite as supple as Cotic’s SolarisMAX – a fellow 29er trail hardtail of the long & slack variety. There’s a few reasons for this. In a Medium size, the SolarisMAX’s wheelbase is longer overall, with 20mm longer chainstays and a 20mm longer reach. The skinny steel frame is also a touch more compliant, which is emphasised by the longer rear centre that has inherently more flex to it. This adds up to a little more stability at high speed, giving the SolarisMAX a slightly calmer and more grounded ride quality on the descents.
There’s a caveat to that assessment though, since I’m comparing my personal experience from testing Medium sizes in both. Because of the DownRock’s scaled sizing however, the wheelbase does get proportionally bigger on the larger frame sizes. So an XL DownRock is in fact longer in both its reach and its overall wheelbase than an XL SolarisMAX. That means the comparison doesn’t hold for taller riders, who may find the DownRock to be the smoother and calmer performer at speed.
That aside, I do like that there is flexibility when approaching frame sizing on the DownRock. As mentioned above, I could potentially ride the XMD size (though I would need a slightly shorter dropper post). That would get me an extra 15mm more reach, which would increase the bike’s stability. If you were chasing more of that high-speed aggression, then upsizing is something to consider.
It’s also a pretty easy upgrade to fit a longer air shaft to the Pike fork and extend the travel to 140-150mm, which would further bolster the DownRock’s enduro aspirations. It wouldn’t hug the ground as closely though, and you would give up some of the agility that makes this bike so much fun to ride.
What Does It Struggle With?
Obviously, the DownRock is no XC bike. While the big tyres, slack head angle and roomy front end make it a speed-hungry beast on the descents, they also conspire to make it harder work on tighter and more pedally terrain.
Because of the lean angle the DownRock warrants to get it around each corner, I found that on more natural, old-school XC singletrack, it was pretty common to blow out wide on the sort of surprise corners that end up being sharper than you first anticipate. This was particularly the case if I still had the saddle at full mast, which makes it harder to lean the bike over. This forces you to turn the bars instead, and that causes understeer. That kind of riding also tends to be in places where tree clearance is limited too, where the huge 800mm bars become a problem.
Ultimately the DownRock’s contemporary geometry requires a contemporary handling approach, and it also suits more contemporary trails that are bigger, faster and filled with high-velocity berms, rollers and doubles. It hums along at speed, and being a hardtail, it rides best when you have momentum on your side to carry you over the chunder.
That means it can also be a punishing bike to ride if you’re tired or just having an off day, where you’ll feel the full amplitude of every bump and hump on the trail. Longer descents are also quite fatiguing – something I experienced on the 30km Cascade trail at Lake Mountain, which has over 1500m of descending from top to bottom over a 2.5 hour ride. The DownRock handled it like a champ, and there was nothing I couldn’t ride on it, but geez my calves were feeling it the next day!
One idiosyncrasy that took a bit of getting used to is the slightly short cockpit feel when the saddle is at pedalling height. Even though the reach is generous, the effective top tube length is less generous at 609mm – a direct result of that steep 75.75° seat tube angle. Along with the short stem, the DownRock can feel a bit cramped on the flats, and on longer rides I found there to be more pressure on my shoulders and upper back.
You can immediately feel the benefit as soon as you head upwards though, where the steep seat angle places your hips further over the cranks so you’re able to get more power down onto the pedals. As well as being efficient to climb on, it’s also pretty comfy too.
The short stem can make the steering light and floppy at slow speeds, so you’ll need to keep your concentration up as the gradient increases. And while the low hanging BB works well elsewhere, it does lead to more pedal clearance issues on technical climbs. This is more pronounced with big flat pedals for sure, though it was something that I noticed less and less throughout testing, presumably as I subconsciously altered my timing.
Once I’d adjusted my technique, I was actually really impressed with how well the DownRock negotiated tricky ascents. There’s tonnes of grip out of those big tyres, and since the front end isn’t too tall, getting your weight onto the front wheel doesn’t require too many yoga moves. Sure, a longer stem and narrower bars would help improve climbing performance, but the DownRock climbs fine for a trail bike, and I’d be reluctant to mess around with its already superb handling.
Component Highs & Lows
I won’t bore you with too much detail about the parts strapped to our DownRock test bike, as I suspect most prospective buyers are more interested in the frame itself. If it were me though, I’d be seriously considering the frameset package. The Pike is a brilliant performer, and it’s a big contributor to the DownRock’s off-road capabilities. Needless to say that if you don’t have any rear suspension, you want the front to be as high performing as possible, and the Pike Ultimate takes care of things beautifully.
The new generation Reverb C1 dropper post has also been flawless throughout testing, with a fast and light action that is right up there with the Fox Transfer and not too far behind the superb BikeYoke Revive. The hydraulic 1X remote requires a decent amount of thumb force to engage, but otherwise I had no other issues to speak of.
In regards to the wheels on our test bike, Curve specs its own Dirt Hoops, which use DT Swiss 350 hubs, Sapim spokes and carbon fibre rims with a 30mm inner width. With an RRP of $2,198, they’re a contributing factor to the complete bike’s high price tag. From that perspective, I’d like to see Curve offer a cheaper alloy wheelset option, particularly as these carbon wheels are quite stiff, which you notice more on a hardtail.
For those who are interested, I’ve actually had a set of these wheels on test for a few months now. Check out the first look story here, and stay tuned for a separate review coming on those soon.
Flow’s Final Word
Curve’s new DownRock is a very worthy example of the modern trail hardtail, and it’s real-world proof that considered geometry can make all the difference – even if you don’t have a rear shock.
The DownRock embodies the inherent advantages of the hardtail platform. It’s responsive, agile, and ludicrously adept at carving turns. But with the chunky Pike, high volume 29er tyres and the long front end, it’s also capable of revving up to some ridiculous speeds that’ll have your adrenaline pumping in a way that full suspension bikes can only dream of. Carmody has managed to maintain a terrific balance between stability and agility, something that isn’t easy to do.
Coming from a full suspension bike, it’s an addictively rewarding bike to ride. Flow isn’t fed to you on a silver spoon with this bike – you have to earn it. And when you do, it is so very satisfying.
Yes, it is very expensive. For that reason, I’d love to see Curve investigate a steel option to bring this kind of riding experience to a lower price point.
Believe it or not though, taking on board the build quality, geometry and features of the DownRock frame, it’s actually a pretty damn good price relative to other titanium frames out there. Is it worth it? Well, that’s entirely up to you. However, logic would dictate that it is not, since an equivalent steel frame is a lot cheaper and not that much heavier. But nobody buys a titanium frame based on logic – simply wanting one is a sufficient enough reason on its own.
And if we’re talking about logic, most people would just buy a carbon full suspension bike from a big brand and be done with it. The DownRock isn’t for most people though. It’s more involving and demanding to ride than a cushy full susser, and that has limited mass market appeal. But if you’re the sort of rider who feels that modern trails are too sanitised, or that modern bikes are making old trails feel sanitised, a hardtail like the DownRock might be exactly the remedy you’re looking for.
Curve DownRock Build Specifications
- Frame | Ti-3Al-2.5V Titanium, 0mm Travel
- Fork | RockShox Pike Ultimate RC2, Charger 2 Damper, 42mm Offset, 130mm Travel
- Wheels | DT Swiss 350 Hubs & Curve Dirt Hoops Wider 40 Carbon Rims, 30mm Inner Rim Width
- Tyres | Bontrager XR4 Team Issue 29×2.6in
- Drivetrain | SRAM GX Eagle 1×12 w/GX Eagle 32T Cranks & 10-50T Cassette
- Brakes | SRAM G2 RSC 4-piston, 180mm Rotors
- Bar | Joystick 8-BIT LT Alloy, 28mm Rise, 800mm Width
- Stem | Joystick Binary, 31.8mm Diameter, 35mm Length
- Seatpost | RockShox Reverb Stealth Dropper Post, 31.6mm Diameter, 175mm Travel
- Saddle | Ergon SM Pro
- Size Tested | Medium
- Weight | 12.1kg (as tested, weighed without pedals)
- RRP | $8,699
Mo’ Flow Please!
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