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GMX+ Steel

GMX+ Steel

Regular price $5,649.00 AUD
Regular price $0.00 AUD Sale price $5,649.00 AUD
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Customers outside Australia are liable for import fees which can add 25-30% for EU and UK shipments (compared to Australian RRP).
Groupset + Wheelset
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For info on availability, please contact,
call us on 03 9088 0274.

Alternatively, Enquire Now.


Click to zoom into the geo chart.

For more information on the GMX+ geometry, click here


Shipping for bikes is included in the overall sales price.


Check HERE for further info regarding custom paint, bike set up and more.

The reach on the geo chart looks long. What size is good for me?

The short answer is that the reach number may be somewhat deceiving as the frame is designed to be run with a shorter stem. That, in combination with the comparatively steep seat angle, reduces the effective reach of the frame.

Please reach out to if you have any questions about sizing.

Read more about the GMX+ geometry here: GMX+ Geo Blog

Why flat mount?

There are very few drop-bar groupsets available with post mount calipers, so we decided to introduce flat mount on GMX+ Steel to make the groupset selection for drop bar setups easier.

What are those black brackets on the downtube for?

In order to reduce the number of holes and M5 mounts added to the downtube, and to add stability to the offset mounts, we decided to make these offset mount support guides specifically for the GMX+ Steel. These guides must be used when attaching bottle cages to the offset mounts.

What are the extra plates with three holes I got with my SM or XS frame?

These are adapter brackets for the rear M5 mounts so you can attach a regular bottle cage to the back of the chainstays and seatstays. The plate is not needed for sizes MD and up.

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The New Steel Adventure Bike Inspired by the Overlanders

Built on the success of its titanium GMX+ cousin, Curve is proud to present the GMX+ Steel. After three years of development and testing, Curve's steel bikepacking bike is finally available in two colourways.

Introducing the Curve GMX+ Steel in Roadhouse Pink. This iconic colourway pays homage to the sun-faded pink paint of the legendary Pink Roadhouse in Oodnadatta. It's a hue that captures the spirit of the outback, where the scorching sun leaves its mark on everything it touches. It's a colour that tells a story of resilience, adventure, and the endless possibilities of the open road. So, gear up and embrace the allure of the harsh but beautiful Australian outback with the Curve GMX+ Steel in Roadhouse Pink, and get ready to create your own unforgettable adventures.

The Nitro Chocolate colourway is a mesmerizing fusion of rich chocolate brown with a subtle sparkle that evokes the enchanting play of moonlight on a remote gibber plain. It's like having a taste of outback Australia's magic with you as you ride. The Nitro Chocolate colourway is an invitation to embrace your spirit of adventure, to chase the moonbeams and hit the lonely backroads of the bush.

The GMX+ is inspired by the intrepid Overlanders of the 1890s, who covered incredible distances across the harsh Australian outback without support. We have designed a bike that can do the same, but with much more ease using today's modern technology. The GMX+ is an adventure bike designed with wide tyre clearance thanks to our innovative carbon fork, ultra-wide drop bars for stability, and numerous mounting points and generous amounts of room for carrying water or other gear.

Tested in real-life conditions, the original GMX was designed for Race to the Rock, a harsh, remote desert race in Australia. With testing came improvements to the bike geometry and fork clearance, and so the GMX+ was born. It's our very own reimagination of a bikepacking bike. In recent years, the GMX+ has taken on some of the most challenging races worldwide, including the Tour Divide, Silk Road Mountain Race, and Race to the Rock.

  • Carry More

    The GMX+ Steel lets you carry more water and pack more gear. The steel frame includes mounting points on the rear stays and offset mounts on the downtube, allowing riders to run a full-size frame bag plus 1 litre bottles to either side. The Seek 430 FM fork has 4 x M5 heavily reinforced mounting points on each side, with a recommended maximum load capacity of 7 kilograms across three mount points (on each side). You read this correctly - it's a carbon fork able to carry a remarkable 14 kilograms of load safely!

  • Class Leading Carbon Fork

    Our Seek 430 FM fork has been made to work in unison with our GMX+ (Ti & Steel) framesets and our popular Walmer Bar and Remlaw Bar. It improves on the original Seek 430 fork with updated brake hose and dynamo cable routing, the introduction of flat mount brakes and the addition of four heavily reinforced M5 mounting points per fork blade that can carry up to a whopping 7 kg each (maximum) when secured across three mounts! That's a total of 14 kg that can be safely carried on the Seek 430 FM! To achieve this, we left the industry-standard rivnuts behind and instead developed our own unique thru-mounts, completely re-thinking the way the mounts are added to the fork blade.

  • Drop Bar, Flat Bar or Riser Bar?

    The GMX+ Steel can accommodate a drop bar or flat bar. Any wide drop bar, especially our Walmer Bar, will work with a shorter stem, as will our unique Remlaw Bar. Other flat bar designs will also work well, but may require a longer stem. Due to the low front end on the GMX+ Steel, which isn't corrected for suspension, an even more relaxed touring position is possible with a high-rise flat bar.

  • Frame Sizing

    The GMX+ Steel ranges from size XS to XL. Sizes SM–XL are designed for 29" wheels. 27.5" wheels are required for size XS to ensure optimal performance. For more info on the GMX+ geometry click HERE!

    There is ample room for bikepacking bags on all frameset sizes. To make sure current, prospective or custom bagging fits your frame size please see our Bagmaker Drawing page.

  • Want to Carry More?

    With a wide range of frame and fork mounted rack systems on the market, and with more appearing every week, it is important to understand which rack systems are compatible with your Curve frame and fork, and how to mount them correctly in order to ensure safe riding, avoid damage and voiding your warranty. Before mounting a rack, we strongly recommend you get in touch with us to confirm compatibility and the correct mounting procedure. This will minimise the risk of injury, product damage and voiding your warranty. Your local Curve dealer, or the team at Curve HQ, can also help you select a rack system and mount it to your bike for you.

GMX+ Steel Specifications



- Columbus Cromor & 4130 chromoly
- 7x cage mounts
- Rear rack mounts
- Clearance max 3.0" tyres
- 1x chainring only (Max 38t)
- 12 x 148 mm (boost) spacing
- 160 mm flat mount brake (with adapter)
- 27.2 mm ID seat tube
- T47 BB (73 mm)

Seek 430 FM Fork:

- Carbon construction
- Non-suspension corrected
- 8 x M5 mounts (4 per side)
- 430 mm axle to crown
- 55 mm offset
- 15 x 110 mm (boost) spacing
- 160/180 mm flat mount brake
- 1 1/8" - 1.5" tapered steerer

Curve Headset:

- 44/56 mm zero-stack


- Curve 29.8 mm Black Alloy seat clamp
- Curve Cocky Headbadge
- 15 x 110 mm front Relaxle
- 12 x 148 mm rear Relaxle
- Carbon steerer expander
- Headset spacers (33 mm total)
- Spare rear derailleur hanger
- Bolt on cable guides, incl. 2 x offset mount support guides
- Chainstay / Seatstay cage mount adapter (Size XS & SM)

Groupset Options

SRAM Rival-Eagle eTap AXS 1 x 12
Shifter/Levers - Rival AXS eTap 1x12 sp - LHR / RHF
Brakes - Rival D1 HRD Flat Mount Disc // CL Rotors 180 mm front | 160 mm rear
Crank - GX Eagle DUB - 32t | XS-SM: 165 mm | MD-XM: 170 mm | LG–XL: 175 mm
Bottom Bracket - Curve T47 DUB 73 mm
Rear Derailleur - GX Eagle AXS Lunar 10-52t
Cassette - XG 1275 EAGLE 10-52t 12 sp
Chain - GX Eagle 12 sp


SRAM Apex-Eagle 1 x 12 Mechanical
 -Apex 1x12 sp - LHR / RHF
Brakes - Apex Flat Mount Disc // CL Rotors 180 mm front | 160 mm rear
Crank - GX Eagle DUB - 32t | XS-SM: 165 mm | MD-XM: 170 mm | LG–XL: 175 mm
Bottom Bracket - Curve T47 DUB 73 mm
Rear Derailleur - Apex Eagle 10-52t
Cassette - XG 1275 Eagle 10-52t 12 sp
Chain - GX Eagle 12 sp


Dirt Hoops Alloy - 29” SM-XL / 27.5” XS
Curve alloy off-road wheels:

- 30 internal x 35 external x 19 deep
- Front Hub: SP Dynamo PL-8X 15 x 110 (6-Bolt) 28H
- Rear Hub: DT Swiss 350 28H 
-Spokes & Nipples: Sapim Race & Brass Secure Lock

Finishing Kit

Bars - Curve Walmer Bars
XS: 46 | SM: 50 | MD-XM: 55 | LG–XL: 60
Stem - SRAM Atmos 60mm
Seatpost - Zipp SC 0 Setback 27.2 mm
Saddle - Velo Saddle
Tyres - Mezcal III 29x2.6 / Ranger 27.5 x 3.0 TCS
Bar Tape - Curve black anti-shock

Please Note: Spec subject to change according to availability

Customer Reviews

Based on 1 review
The Mawson Trail, South Australia vs. steel GMX+

Just completed South Australia’s off road Mawson Trail (starting Adelaide), approx. 850km on a steel GMX+ (wireless X01 derailleur) purchased ~Sep-23 from Omafiets, Sydney.
Bike serviced pre-ride at Cyclemax Crows Nest with extra sealant.

Bike was flawless over the Trail, no mechanicals or punctures.

Walmer bars and Mezcal tyres helped out over the many descents and probably saved the day during the last descent into Mt Little Station (you’ll know the one).
Gearing was spot on, rode many climbs that others walked (e.g. day 1 Batchelor Rd). One click down/upshift of three gears brilliant for the many creek crossings in the Flinders Ranges.

All terrain handled: deep sand and gravel; fist sized rocks and babies heads; excelled on Corrugation Road Hell approaching Rawnsley Park Station.

The GMX+ is an imposing bike and can seem overbuilt - until it rides over everything with confidence and predictability, while loaded like a donkey.

Bike as stock except swapping the saddle for a Selle San Marco Shortfit 2.0 Supercomfort Racing saddle and DMR Vault pedals.

Additions: Tailfin alloy rack (thru axle 1.5mm pitch) + AP20 trunk bag; Tailfin 1.5L top tube pack; two Tailfin large Cargo Cages; Frameworks Design half frame bag (70mm width); 4L CrankTank; two Sea to Summit Big River 20L dry bags; Arundel steel bottle cages; four Bike Bag Dude feed bags; Apidura Backcountry Down Tube 1.8L pack; Sinewave Revolution USB Charger; Busch & Muller Secular Plus rear light; Schmidt SON Edelux II front light; Shutter Precision/SP Dynamo Connector.

Tip: get the MT app for info on each section and the current hazards, e.g. to avoid the prickles around Jamestown.
Used David Hume’s GPX file for Garmin which is 98% accurate. MT trail markers do exist.