German bike brand Rotwild say the new R.X275 is a whole new category of bike; a trail bike with e-assist, but not a electric mountain bike as we know it


Full-powered, mid-powered, super light… there’s a whole load of options in the electric mountain bike ecosystem, and Rotwild has just added one more to the mix. The new Rotwild R.X275 is a different breed – a short travel trail bike with e-assist. So far, so normal, we hear you say, but dig into the details and there differences become apparent.

Need to know:

  • 130mm front, 120mm rear travel
  • Carbon frame, including rear triangle, and handlebars
  • TQ drive unit supplies max 50Nm torque
  • Boost Button deploys e-assist when required
  • S, M, L, XL

Rather than providing a high level of motor assistance while riding, the R.X275 instead provides very subtle assistance, and has a Boost Button which does exactly what it says on the tin. While riding, should the rider require additional power to climb a steeper gradient or obstacle, for example, pressing the boost button will provide motor assistance.

Rotwild R.X275 Ultra electric mountain bike

“[The] linchpin is the principle of the Boost Button developed by us”, explains ROTWILD Managing Director Peter Schlitt. “The focus of the R.X275 is clearly on the rider’s own rhythm. He or she is the driving force. The motor provides constant and subtle support. For those moments on the trail when thrust and support are required, the rider releases extra energy completely intuitively via the BoostButton. Just like he operates the bike shifter and seat post.”

Rotwild R.X275 boost button electric mountain bike

The Boost Button offers more power from the motor when pressed

This assistance will offer the rider up to two times their own power input, up to a maximum of 300 watts. Assistance will continue for a maximum of 30 seconds, or as long as the button is pressed.

The button itself is mounted on a ring-style mount which is incorporated into the cockpit, operating in a similar fashion to shifter or seatpost controls.

There are three levels of support, or support modes, but unlike other electric mountain bikes these can’t be changed mid-ride. Instead, these are selected before embarking on a ride.

Rotwild R.X275 TQ motor drive unit electric mountain bike

The TQ HPR50 drive unit

Support comes from the Integrated Power Unit (IPY) 275, which consists of a TQ HPR50 motor which offers a maximum of 50Nm torque, and a battery developed by Rotwild. The battery consists of 21700 individuals cells, integrated into the downtube, which delivers 250 watt hours with software programmed to regulate energy output and optimla interation with the drive unit.

Rotwild R.X275 range extender electric mountain bike

Rotwild range extender pack

There is also an optional range extender, with the dimensions of a 0.5 litre bottle which fits into one of the two bottle cages on the bike (size small has one only). This provides an additional 160 watt hours, and weighs a reported 1,140g.

Rotwild R.X275 toptube diplay electric mountain bike

The diplay is located on the top tube

This different style of bike is also aimed a very particular type of rider. Specifically, athletes.

“Our target group are athletes who follow an individual training plan and whose focus is on permanently increasing their own performance,” says Schlitt. “That’s why we call the R.X275 ‘the athlete’. Our approach in the development was to create a very light trail bike with eAssist. The design with theBoost Button allows us to find just the right balance between biological power and support. We reduced everything to get the maximum riding experience out of it.”

The frame is hand-built from ultra-modulous carbon, and comes in at an impressive 2,350g frame weight for the size medium, with a full build weighing in at a reported 15.3kg for the size medium in the Ultra configuration.

There are two build options, both of which feature carbon handlebars and flex seat stays to increase frame compliance. The premium R.X275 Ultra retails at €12,499 and includes a fully integrated carbon cockpit, and the R.X271 Pro at €9,499.