German CNC’d mountain bike maker Actofive has an interesting new future-proof eMTB frame concept in development. Instead of getting locked in with one very expensive ebike purchase today, their concept is to build a modular frame platform that could adapt to you as your needs change. Want to ride a long-travel, mullet Pinion gearbox enduro bike in bikeparks now? Then, maybe next year convert it to a lightweight 29er all-mountain eMTB for everyday pedal-assisted trail riding? The new Actofive eMTB frame platform can totally adapt to that… and much more.
ActoFive developing modular eMTB/MTB frame concept
Founded on their engineering & manufacturing expertise, Actofive was established to create high-performance mountain bikes. But as eMTBs became more prevalent and ebike drive systems became lighter and more capable, founder Simon Metzner began to wonder, “What if Actofive made an e-bike frame?“
He didn’t want to just slap a motor onto one of his existing designs. Let the original enduro P-Train, or the simpler trail I-Train, stand on their own. Instead, he wondered if Actofive could craft an even more “versatile and flexible” frame platform.
The result is a highly modular frame that can be adapted to how the buyer wants to ride. And you can still change the setup later, too. Actofive explains that many of their customers like to tweak their bike setups. Like changing travel, geometry, wheel sizes, and even suspension kinematics. So this eMTB/gearbox concept simply takes that adjustability to a next level.
Hollow, clamshell construction, updated and uncovered
Actofive’s signature sleek CNC’d aluminum construction relies on complex machining. And a two-piece clamshell-style construction to bond together their lightweight, hollow front triangles. But fitting a battery inside of that and making it easily removable presented a real engineering challenge. With most of the bottom of the downtube removed from a structural perspective, Actofive needed to start over from scratch to get the frame stiffness they needed. “By applying topology optimization, wall thicknesses are dynamically tailored directly along the load pathways of the open downtube—delivering uncompromising frame stiffness at a minimum weight.“
The solution means this would be the first Actofive frame you will actually get to see the insides of. Open up the downtube to reveal some more of the intricate machining we got a glimpse of when touring their workshop a few years back. The open design also lets Actofive create a relatively slim downtube for an eMTB. It uses a low-profile downtube cover for the smaller 400Wh internal battery. Or enough room for roughly 2 full-size water bottles inside in gearbox bike mode. Or a deeper, extended downtube cover to fit a 600Wh battery inside.
Key Tech Details
- fully CNC-machined, hollow 7075-T6 aluminum frame, manufactured in-house in Dresden, Germany
- modular BB mount for either ebike motor or gearbox
– eMTB mode with a Maxon AIR-S 90Nm/620W motor & 400/600Wh removable battery
– pedal-powered mode with a Pinion C-line gearbox, and extra internal frame storage space - classic 4-bar Horst-link suspension layout with adjustable rear travel
- Enduro 170mm rear (180mm front) or Trail 150mm rear (170mm front) travel modes
- MPT° (Modular Pivot Tech) lets Actofive tweak suspension kinematics, allows for swappable main pivot inserts in the frame that can change anti-squat/anti-rise or even overall geometry
- NYT° (No Yoke Tech) provides high rear-end stiffness without a chainstay bridge. thanks to a splined main pivot axle connecting the chainstays
- ART° (Adjustable Ride Tech) allows for short or long chainstays and multiple wheelsize combinations. Start with classic 27.5/29 mullet, full 29er, or new ‘super mullet’ 29/32″ combinations
- ATT° (Adjustable Travel Tech) uses swappable lower shock mounts to change rear wheel travel: 170mm of rear wheel travel with a 65mm stroke shock, or 150mm of travel with a 55mm stroke
Actofive eMTB Concept – Next Steps & Future Availability
For now, the Actofive eMTB is only a concept that Simon is currently working on. It’s been more than half a year on the FEM & engineering development side. And Actofive is close to finalizing the design, having already 3D-printed several key frame sections to refine some details. Next step, Actofive plans to machine the first complete prototype this autumn. Then, ride-test it in both ebike and gearbox bike modes. The ultimate goal is to refine the eMTB concept over the winter. And have it ready for consumers in Spring 2027.
As for pricing, Actofive didn’t set anything, just yet. But keep in mind, it is a lot more material to machine and more mechanically complex than Actofive’s current €7k P-Train or €6k I-Train frames. Plus, adding a Maxon drive system would probably add at least €1-1.5k on top of that, and a Pinion gearbox isn’t likely to be much cheaper.
Another interesting point… Actofive says they are only focusing on the light but powerful Maxon AIR-S ebike motor system for the moment, as it “fits our needs and design the most” according to Simon. But he acknowledges, Actofive certainly could adapt the modular mounting to work with other eMTB drive systems in the future, too. That seems like one of the most appealing aspects to us regarding a modular frame platform, especially with the combined motor + gearbox eMTB concept heating up this summer.
What do you think?
For now, Actofive want to gauge interest from the public, and hear what mountain bikers and e-bikers think of the concept. That’s where you come in. If you would like to have a modular MTB platform that could be adapted to both eMTB and gearbox mountain bike modes, Actofive would love to hear your thoughts. Feel free to drop your comments in below, and we’ll make sure Actofive hears your feedback.
