curve downrock titanium hardtail
13 Nov 2019

Melbourne-based brand Curve Cycling has just launched a brand new titanium hardtail called the DownRock. This ain't no flimsy XC bike though...

The DownRock is a brand new, bird-flippin’, trail-rippin’ hardtail that has just been launched by the crew from Curve Cycling. Joining the Melbourne brand’s existing off-road lineup that includes the UpRock, GXR and GMX, the DownRock is pitched as being the most capable and the most naughty of the lot. We’ve just received a complete Curve DownRock for a full shakedown and review, but before we get it dead-filthy like, let’s take a closer look at this lovely mountain bike to see what makes it special.

curve downrock titanium hardtail
Aussie brand Curve Cycling is ready to unleash its new hardtail pinner; the DownRock.

Ooh Shiny!

That’s because it’s titanium mate! Ti-3Al-2.5V to be exact, and from first inspection, it appears to have been masterfully welded together with some extremely neat joins on display for all to see. Why titanium? Because it offers a unique blend of strength, weight and durability, and when it’s all put together, offers a zingier ride quality than alloy, while being lighter than steel. Plus, just look at it!

curve downrock titanium hardtail
That ain’t no painted frame…
curve downrock titanium hardtail
Nice short back end on our Medium test bike.

That’s A Big BB Shell – What’s Inside?

Up front, the DownRock gets a shapely tapered head tube to house a clean zero-stack headset. At the opposite end, cowled dropouts are locked down with a simple 148x12mm alloy thru-axle. Partway between the two, you’ll find an enormous T47 threaded bottom bracket shell – a relatively new frame standard that aims to offer the structural benefits of a big diameter PF30 bottom bracket shell, with the creak-free reliability of a threaded system.

T47 (named after the 47mm external diameter of the BB cups) allows for larger BB cups that thread into the frame, rather than pressing in like PF92 and PF30 bottom bracket systems. Compared to a traditional 73mm BSA threaded BB shell, it offers more surface area for the downtube, seat tube and chainstays to weld to, which creates a stiffer and stronger junction in a part of the frame that experiences high loads. Up until now, T47 has mostly found favour with smaller frame builders, though with Trek recently adopting the standard for its new Crockett cyclocross bike, there’s a good chance we’ll be seeing it on more bikes, from more brands, in the future.

curve downrock titanium hardtail t47 bottom bracket
It’s a threaded bottom bracket shell, but a bit bigger than normal.
curve downrock titanium hardtail t47 bottom bracket
The T47 bottom bracket shell offers a big platform to join all those tubes together, and it also allows for a variety of different crank sizes to be used.

The Big Fork, Fat Rubber & Long Dropper Club

Being a hardtail that’s designed to seek out the good times, the DownRock is ready to accept 130-150mm travel fork. However, Curve specs both the frameset and the complete bikes with a 130mm travel RockShox Pike Ultimate fork. With that fork, you’re looking at a 65° head angle and a very healthy BB drop of 62-66mm, depending on the frame size. Along with the generous reach measurements, the DownRock puts a big fat tick in the long, low and slack boxes.

Helping to take the sting out of the trail further, the DownRock is rolling on 29in wheels all the way from the Small through to the XL size. There’s clearance for up to a 2.6in tyre in the back, though our test bike has an e*thirteen rubber combo with a 2.4in All-Terrain up front and a 2.35in Semi-Slick out back.

curve downrock titanium hardtail rockshox pike rc2 ultimate fork
While the DownRock has been tested with a 150mm travel fork, Curve has optimised the geometry around a 130mm fork.
curve downrock titanium hardtail e*thirteen semi-slick tyre trsr
High volume e*thirteen rubber front and rear, with a semi-slick out back.

Along with modern geometry and high-volume rubber, dropper posts have been an absolute boon for the humble hardtail. With your arms and legs playing a bigger role in impact-absorption duties, being able to crush the saddle out of the way offers a tonne more room for moving around the cockpit while bending your limbs in preparation for the next huck-to-flat. To make the most of the latest crop of big travel dropper posts, the DownRock employs a short seat tube – our Medium test bike has a 410mm seat tube, and comes spec’d with a 170mm dropper. Larger frames get a whopping 200mm travel party post!

curve downrock titanium hardtail
This thing looks fun standing still!

Size-Specific Seat Angle & Chainstays

As you’ll see below, there’s been some serious attention to the geometry on the DownRock. After all, it’s one of the most important aspects of any mountain bike, and even more so on a hardtail.

To begin with, there are five frame sizes, rather than the usual four. The ‘Extra Medium’ (love that name!) slots in between the Medium and Large frame sizes, and offers up more choice for riders who have a particular reach measurement in mind.

Another aspect that Curve was eager to address is the rear centre measurement, which has been scaled proportionally for each frame size. So as the front centre (reach) gets bigger, so too does the rear centre (chainstay length). The idea is to maintain weight distribution as much as possible between frame sizes, while keeping the back end compact for responsive handling through the turns. At least, that’s the theory anyway.

curve downrock titanium hardtail
Short seat tubes allow for long dropper posts. With the saddle slammed, it’s got a total BMX vibe about it.
curve downrock titanium hardtail
Stubby 35mm long stem mates to a nice long top tube.

Likewise, the seat tube angle is quite different between each of the five frame sizes. And indeed on the smaller frames the seat tube has more of a bend to it, whereas it’s completely straight on the XL frame size. This is all about producing a similar effective seat tube angle (a rather steep 75.75°) when measured from the stack line.

It’s no doubt a more expensive way of producing a frame, because you need different tubing for the rear of the bike for all five sizes. But it’s cool to see Curve make that commitment to maintaining consistent sizing and rider fit throughout the range. This is something we’ve seen Norco do with its latest Sight and Optic models, and we’d like to see more brands share that same commitment.

curve downrock geometry
Curve DownRock frame geometry. Note the ‘Extra Medium’ size. Nice!

Curve DownRock Frameset Features

  • Ti-3Al-2.5V Titanium tubing
  • Tapered Zero Stack headtube
  • Designed to accommodate 130-150mm travel forks
  • 65° head angle
  • 75.75° effective seat tube angle
  • Reach: 422mm (SM), 444mm (MD), 459mm (XM), 474mm (LG), 496mm (XL)
  • Chainstay length: 420-445mm (size dependent)
  • T47 bottom bracket shell
  • Boost 148x12mm thru-axle dropouts
  • Max tyre clearance: 29×2.6in
  • Max chainring clearance: 32T (SM), 34T (MD-XL)
  • Two bottle cage mounts
  • Claimed weight: 2000g (XL size)
curve downrock titanium hardtail
A lovely tapered head tube hides a zero-stack headset.
curve downrock titanium hardtail
Room for up to 2.6in tyres back there.
curve downrock titanium hardtail sram guide g2 rsc brake
A post-mount disc brake and a bolt-up 148x12mm thru-axle keep the back end slim and tidy.

Choose Your Own Hardtail Adventure

Curve offers the option to buy the DownRock as a standalone frame that comes with a headset, seat collar and thru-axle for $3,399. There’s also a frameset package for $4,499, which adds in a RockShox Pike Ultimate RC2 fork and a Reverb Stealth dropper post. Or you can go for a complete bike, like the one we have here, which sells for $8,699.

Here’s a closer look at the spec on the complete bike;

  • 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 | e*thirteen All-Terrain TRSr MoPo 29×2.4in Front & Semi-Slick TRSr 29×2.35in Rear
  • 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, 170-200mm Travel
  • Saddle | WTB Silverado Pro
  • RRP | $8,699
curve downrock titanium hardtail
All cables and hydro lines run externally under the downtube with bolt-on guides keeping them in check.
curve downrock titanium hardtail
Is a modern hardtail like this enough to bring you over from your full suspension bike?

So what do you folks think of the new Curve DownRock? Is this a hardtail you’d like to party on? Let us know your thoughts, and any questions you might have for us, in the comments below!

We’ll be hitting the local test loops on the DownRock shortly, so get set for a full review coming soon. If you need more info in the meantime, head to the Curve Cycling website. And if you’re frothing on all this hot hardtail talk, be sure to check out our stories on the new 2020 Norco Torrent, and our recent feature on the custom steel hardtails from Tor Bikes in Beechworth.

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