The Rider at the Center
The development of the ROTWILD R.EXC
The ROTWILD R.EXC is more than just a fast bike; it’s a highly precise tool designed to adapt to diverse trail demands. An adjustable suspension system allows riders to fine-tune their bike quickly and effortlessly for different tracks. The focus is on easy adjustments and personalized tuning. “This is a crucial aspect. Riders must be able to adjust their setup on the go. After extensive testing, we developed a system that offers three different shock mounting points with a simple M5 bolt. You don’t even need to remove the bolt completely, reducing the risk of losing parts on the trail. With just a few quick adjustments, you can change the bike’s handling characteristics on the fly.” For Scheffer, this versatility is a cornerstone of ROTWILD’s philosophy: “A sports device is a functional machine, not a decorative object.”
For Scheffer, this versatility is a cornerstone of ROTWILD’s philosophy: “A sports device is a functional machine, not a decorative object.”
The cockpit of the R.EXC was also designed with adaptability in mind. “Every rider has unique needs,” Scheffer notes. “By adjusting components like handlebars, stems, and grips, the bike can be perfectly tailored to the rider.”
The straight seat tube design exemplifies the R.EXC’s functional approach. It allows for dropper posts with greater travel, offering maximum freedom of movement for riders with longer legs.
“At ROTWILD, we believe functionality should always take precedence over aesthetics. This is particularly evident in the seat tube design of the R.EXC: it’s straight and continuous, enabling the use of dropper posts with extensive travel,” Scheffer explains. “For me, this is a must. Riders with long legs need maximum freedom of movement. While bent seat tubes might look more stylish, they com-promise functionality.”
The Motor: Power, Efficiency, and Future-Proofing
The motor of the ROTWILD R.EXC was also subjected to meticulous evaluation. After extensive testing, the decision was made to use the Shimano EP801, which stands out for its performance, reliability, lightweight design, and versatile adjustability via the E-Tune app.
“The Shimano motor convinced us because it is compact, lightweight, and with 85 Newton meters of torque, capable of handling any situation,” explains Lutz Scheffer, Advanced Design Developer at ROTWILD. “It delivers the necessary power on steep climbs without compromising efficiency.” Motors from Brose and Bosch were also tested beforehand. “Brose has traditionally been a strong partner, and their motors offered an impressive characteristic. They delivered powerful perfor-mance, even at low RPMs, but were a bit too bulky for our frame design,” says Scheffer.
With Bosch, the fixed form factor of the battery was a significant drawback. “For us, it’s clear: a battery must be reliable and quick to remove,” emphasizes Scheffer. “Especially on long tours, no one wants to carry their e-bike into a mountain hut just to charge the battery. In races, teams are allowed to change the battery once. While some mechanics have to remove the motor at top speed, sometimes taking up to 25 minutes for the swap, our Quick-Release system allows for a fast and hassle-free process—no keys or complicated fiddling required.”
The Shimano EP801 offers additional benefits, such as extensive customization through the Shimano app. Riders can adjust settings and easily update features, like the new torque boost, keeping the motor future-proof and adaptable.
“It’s not just about the motor’s performance; it’s also about how seamlessly it integrates into the overall design,” Scheffer explains. “We see the motor as just one component of many, alongside the drivetrain and frame. The ROTWILD R.EXC is a complete package, where every part is perfectly aligned.”
The choice of Shimano has proven to be the right one. “Many top riders trust this motor, and with good reason. It was absolutely the right decision for us,” Scheffer concludes.
Development in Practice: Feedback from a Legend
Lutz Scheffer wasn’t the only one shaping the R.EXC. Former downhill World Cup rider Claudio Caluori was one of the first testers, playing a key role in fine-tuning the bike’s character from its earliest prototypes. “I was thrilled when Claudio immediately felt that ‘Wow’ factor—this bike just rides incredibly well. It takes off smoothly in jumps, exactly how a race machine should perform,” Scheffer recalls. Caluori, known for his exceptional sensitivity and expertise in testing bikes to their limits, contributed invaluable feedback. “Claudio tweaks every setting, adjusts every component, pushing the bike in different directions,” Scheffer explains.
This process involves more than technical data: “A lot of it comes down to feeling. Numbers alone can’t capture the experience. It has to feel right immediately.”
Caluori’s instinct was critical in perfecting the R.EXC. “The average rider might only notice differences of 20% in performance due to a lack of direct reference points,” Scheffer explains. “But someone like Claudio senses improvements of just 3–5% instantly. He has an incredibly fine-tuned awareness of every nuance.”
The partnership between ROTWILD and Claudio Caluori highlights the importance of combining advanced development with real-world testing. “A bike like the ROTWILD R.EXC doesn’t come to life in the lab alone,” Scheffer emphasizes. “It takes experts like Claudio, who have an exceptional feel for a bike’s behavior.”
Thanks to this collaboration, the R.EXC was refined down to the smallest detail — from suspension travel to the perfect balance of stability and agility. “For us, the R.EXC is a milestone,” Scheffer concludes. “It proves that when you dedicate yourself to perfection, compromises are unnecessary.”
