At Bespoked in Dresden over the weekend, Czech robot-wound carbon bike maker CDuro teased us with an all-new gravel bike prototype. Designed as an all-rounder, this prototype gravel bike highlights their unique automated carbon tube & joint manufacturing construction, showcasing every individual wrap of carbon that makes up its structure.
Plus, at the same time, CDuro also announced their carbon Epona enduro mountain bike – which we first shared with you last summer, but had been following for several years through its development – is now available for purchase!
CompoTech’s CDuro Czech robot-made carbon bicycles
We first know CompoTech for their unique in-house-made machine-wound carbon fiber tubing. A carbon tube tech designed from the ground up to better handle the real bending and torsion forces that bike frame tubes actually encounter vs. conventional filament winding, these tubes are remarkably strong and impact resistant, even when made incredibly lightweight.
It’s the same tech we’ve been riding in Festka road and gravel bikes for more than a decade.
I even got a first-hand look into CompoTech’s in-house Czech carbon tube production back in 2017, together with Festka as they were preparing to make tubes for my own custom One Gravel bike – itself the prototype that would become Festka’s Rover. Although everything was so super secret at the time, so I really wasn’t allowed to share what was happening inside their factory.
I did in fact, already catch a glimpse of an early prototype that CompoTech was working on, which would become their CDuro Epona enduro bike… which itself is now available.
CompoTech Integrated Loop Technology drives CDuro bikes development
But CompoTech’s latest and most advanced automated manufacturing technology is really what fuels them to create their CDuro Bikes brand.
As a manufacturer, the vast majority of CompoTech’s carbon products go into industrial applications where their light weight, stiffness, and vibration damping make them outperform conventional metal parts or other composites… the engineers behind the brand like to ride bikes. So while high-performance carbon tubes were a great starting point for tube-to-tube bike builders like Festka, it was the automated manufacturing of joints between tubes that allowed CDuro to create its own bikes.
This new Integrated Loop Technology (ILT) takes automated carbon tube production to a new level with an automated “integral joining tech” that lets a robot join the tubes.
That way CDuro first makes individual lightweight carbon tubes with a more conventional filament winding ‘loom’ attached to a spinning spindle. Then for example, they cut & miter a downtube, bottom bracket shell, and headtube to be assembled as one. And a robotic arm joins the tubes together, wrapping longitudinal fibers over the joints and along the full length of the tubes to complete the structural needs of the assembly. And finally, the robot overwinds the tube junctions to create the desired tension in the long fibers and lock in the joint before wrapping it all in tape to squeeze out any excess resin and finalize the structure.
ILT carbon up close: before & after
This ILT process allows CompoTech to fully automate the creation of the key frame subassemblies of both their first bike – the single-pivot full-suspension Epona enduro mountain bike – and this more traditional diamond frame gravel bike prototype. In that way, CDuro machine-winds the bikes’ backbone as a single element. And then, they simply slide other tubes in and bond them into place.
CompoTech show how the downtube assembly of the Epona is made in that video above, but don’t reveal exactly what happens in the next step. However, that long robot arm suggests much bigger assemblies could be rotated through the automated production.
Plus, CDuro describes the complete front triangle of the Epona mountain bike and the front triangle of this gravel prototype as being made in one piece.
CDuro robot-wound carbon all-rounder Gravel bike prototype
So the ILT process creates a perfectly automated joint between tubes, but also the continuous longitudinal fibers that reinforce the woven structure of the main frame tubes.
And probably the thing that I love most about the CDuro bikes is that nothing is hidden. While traditional hand-laid carbon always has some human imperfections (like you can see on this prototype gravel bike’s seatstay and chainstay junctions), the automated fiber placement is perfectly where it was designed. Every fiber precisely placed by robots.
The finished product is a strangely skeletal or even industrial aesthetic, at times even looking unfinished. But that’s exactly because CDuro’s robots only place the carbon fiber where they need to from a structural perspective.
In my mind, that’s the beauty of these bikes. Every fiber of carbon is placed there with intention. Nothing extra.
The result on this as-yet-unnamed carbon CDuro Gravel bike prototype is that the overwrapped ILT joints remain open. On their mountain bike, they seal these off to keep out mud and debris. But CDuro still aren’t sure if they would leave the gravel bike more open.
Carbon tube connections up close
CDuro does not entirely automate construction of the prototype gravel bike, though. Robots wind the (mostly) round tubes and create the main front triangle joints. But CDuro CNC-machines aluminum dropouts at the rear, which they then directly bond into their tubes. And then, they connect those chainstays and seatstays to the front triangle with conventional tube mitering and hand-wrapped carbon overlays.
Officially, this is still completely a gravel prototype, and CDuro does not have any real final details of an estimated availability timeline for the new bike. They do describe the gravel bike more as an all-rounder. So it will have gravel geometry inspired by the mountain bikers who have designed it. And while optimizing weight, CDuro prioritize durability over the absolute lightest weight possible for this gravel bike project.
CDuro expects tire clearance in the 45-50mm range. Cable routing will be fully integrated up front, and it will be UDH-compatible. And it likely will add more bottle cage mounts than you see here, but as CDuro say, they would rather cut as few holes into the middle of their carbon tubes, as possible.
100% made-in-Czechia, complete gravel frames will probably sell for somewhere between 2500-3000€ in a handful of stock sizes, starting with raw matte carbon finishes being the most affordable. But we’ll have to wait at least until next spring to get a more concrete timeline.
CDuro Epona carbon enduro mountain bike
But, if you are looking for a unique carbon enduro mountain bike woven by Czech robots, you can already order one of these CDuro Epona frames today.
We first featured the single-pivot Epona last summer at Eurobike where it was sporting this upside-down carbon Intend fork. I’ve also seen it around the Czech enduro racing scene and in line at my local bikepark, piloted by Czech enduro racer Dominika Adamcová.
This is the versatile and capable mountain bike that CompoTech’s engineers wanted to build from the start. CDuro name the Epona after a local technical rocky trail that descends from the highest mountain just above CDuro’s factory in Sušice, at the foot of the Šumava mountains on the CZ/DE border.
CDuro describe the concept of the bike as simple, “a strong, stable, lightweight carbon, and straightforward single-pivot enduro frame platform”. They are not trying to reinvent mountain bike suspension or even geometry design – just to reimagine it with their unique automated carbon construction.
Generally, CDuro builds the Epona up as either a mullet bike with a longer 65mm stroke shock for 160mm of rear wheel travel. Or go full 29er with a 60mm shock stroke for 150mm of rear travel. But for the smallest S-sized bikes, CDuro reduces rear wheel travel to 137mm with a 55mm stroke shock for lower standover with either a 29″ or 27.5″ rear wheel.
In any case, CDuro recommends matching it to a 29″ front wheel and 160-170mm of fork travel.
The bike comes in 4 stock sizes (S-XL) and features pretty standard capable geometry for a lightweight enduro bike. You get a slack 64° head angle, steep 79° seat angle, relatively long 450mm chainstays, and medium-long Reach figures.
Tech details
- CompoTech Integrated Loop Technology robot-wound carbon front triangle
- hi-mod carbon frame 100% EU-made at a claimed 2.2kg without shock
- 27.5 mullet 160mm or full 29er 150mm of rear single-pivot travel on sealed bearings
- threaded or BB92 PressFit bottom bracket
- UDH with 12x148mm Boost spacing
- 180 post-mount disc brake
- internal brake routing, plus optional internal wired 31.6mm dropper seatpost or derailleur routing
Epona – Pricing & availability
CDuro produces the Epona in small batches in 4 stock frame sizes (S-XL), but with each bike dialed in for the individual buyer.
The Epona sells as a frame-only for 3860€. And with a 50% deposit to start the build process, it takes about 8-9 weeks before they will get the frame to you to build up. Pretty much every Epona I have seen built up in person has featured premium Intend suspension, but CDuro is happy to help you find a more reasonably priced build, as well. In fact, Bikerumor is in talks with CDuro to test one with a more conventional build kit on our local trails in the coming months.
