R.EX ULTRA
Racing meets All Mountain
Full Carbon Frame
Racing meets All Mountain. The frame design of the R.EX is an evolution of the ROTWILD World Cup racer R.EXC and is just as unwavering. The frame combines the uncompromising performance of racing with the agility for everyday rides. Made from high modulus carbon, it offers the ideal balance between durability and low weight. Through extensive FEM simulations, numerous prototype builds, and intensive testing, our engineering team has developed the optimal frame design. Each frame is meticulously handcrafted and enhanced with a new surface finish. This is what we mean by: racing technology thoroughly implemented!
Elevated Box Design
Recognizable at first glance: the silhouette of the ROTWILD R.EX is characterized by the new Elevated Box Design and the significantly raised chain stay. The large volume of the carbon swingarm ensures symmetrical stiffness performance. The cross brace between the two chain stays has also been moved upwards, providing the rear wheel with the necessary tire clearance – especially beneficial in muddy conditions. Additionally, chain slap is effectively avoided, resulting in particularly low riding noise.
Shimano EP801 Motor
The Shimano EP801 motor is a standout piece of innovative e-bike technology, perfect for e-enduro racing and challenging trail riding. Its key features include powerful performance, numerous customization options, low weight, openness to future technological developments, and seamless integration into the R.EX frame. With torque up to 85 Nm, the Shimano EP801 provides strong support while allowing the use of ROTWILD's proprietary battery technology.
IPU Carbon Battery 820 Wh
Maximum range with the latest technology! The battery of the R.EX is a proprietary development by the ROTWILD engineering team. For the first time, we are using Gen2 high-performance cells, type 21700, in the R.EX. These offer an impressive capacity of 820 Wh, setting a new benchmark in battery technology. To save weight, we integrate the cells into a very lightweight carbon housing. Thanks to the quick release mechanism, the battery can be removed and reinserted in seconds.
Mid-High Pivot Suspension
The best of both worlds: The more forward and upward positioned pivot point of the R.EX frame combines the advantages of a traditional four-bar rear suspension with those of a high-pivot setup. This design keeps the chain stay length relatively constant during compression, avoiding a particularly high anti-rise value. The result is a very active and responsive suspension, maintaining the sensitivity of the rear end. The anti-rise value remains between 65 % and 49 % throughout the entire suspension travel, effectively preventing brake dive. The anti-squat value stays constant between 106 % and 108 %, ensuring the chain tension stabilizes the suspension, providing efficient power transmission, traction, and high sensitivity of the suspension.
Mullet Setup
Improved roll-over performance and track stability: The 29-inch front wheel makes it easier to roll over obstacles and provides better stability. At the rear, the 27.5-inch wheel creates short, nimble chainstays, offering extra grip, which is especially beneficial when accelerating or on power-intensive climbs. By combining these two wheel sizes, we achieve a balanced ride that offers both stability and agility. The Mullet Setup optimally leverages the advantages of both wheel sizes, making the R.EX ideal for challenging trails and technical routes.
Shimano XT-Di2
Every detail counts. When the race gets really fast, the track profile, your line, and the surface determine the appropriate gear. This is where the Shimano XT-Di2 shines. The electronic shifting ensures precise and reliable gear changes, regardless of conditions or riding style. Despite the higher chain loads in eMTB, it delivers fast and smooth shifts. The Freeshift feature allows selecting the optimal gear when rolling through corners or on fast descents without the need to pedal. With electronic shift buttons, operation of the XT-Di2 is intuitive and easy.
Configuration R.EX ULTRA
Rear Shock
FOX Float X Factory Kashima
Headset
ACROS RW EXC 1.5
Fork
FOX 36 Float Factory Kashima
Handlebar
e*thirteen Race Carbon
Stem
e*thirteen Plus 35
Display
SHIMANO EM800
Seat post
8PINS NGS2.0
Saddle
ERGON SM Sport
Grips
ERGON GD10
Motor
SHIMANO EP801
Battery
IPU820 Carbon - Push+
Charger
ROTWILD - 4.5 A
Crankset
e*thirteen Race Carbon
Chainring
e*thirteen Direct Mount Chainring
Chain guide
ROTWILD EXC
Rear Shifter
SHIMANO XT Di2 8150
Rear derailleur
SHIMANO XT Di2 8150 SGS
Chain
SHIMANO HG 7100
Cassette
SHIMANO CS 7100
Front Brake
SHIMANO XT 8120
Front Brake Rotor
SHIMANO RT800
Rear Brake
SHIMANO XT 8120
Rear Brake Rotor
SHIMANO RT810
Front Wheel
CRANKBROTHERS Synthesis Enduro Carbon
Rear Wheel
CRANKBROTHERS Synthesis Enduro Carbon
Front Tire
SCHWALBE Albert Evo
Rear Tire
SCHWALBE Albert Evo
Errors and omissions excepted.
