Rotwild E1+ FS 27.5 Enduro
The Rotwild E+ Enduro electric mountain bike has been designed for ultimate off-road performance. Rotwild’s E+ Enduro shares the same BROSE motor and aluminium-carbon composite monocoque frame technology as their other electric mountain bikes, but this model has heavier duty suspension including 36mm FOX FLOAT FACTORY KASHIMA forks giving 170 mm travel. The result is simply astonishing: a serious Enduro machine with a 33% higher power to weight ratio than its nearest competitor – its breaking time trial records worldwide.
The Rotwild E+ is stronger – its uni-directional Carbon Fiber / 6066 T6 Alloy monocoque frame make for the most rigid e-bike frame in the world.
The most distinctive feature of the new Rotwild hybrid mountain bike is the Integrated Power Unit (IPU). This part of the bike combines the magnesium motor casing with the carbon composite battery pack to form a rigid structural element, connecting bottom bracket to head stock like they’ve never been connected before. This state-of-the-art engineering never usually gets beyond the perimeter fence of a McLaren or Williams Formula One R&D center. It makes the Rotwild the stiffest electric mountain bike in the world; it won’t twist, buckle, or bend no matter how hard you’re riding it, no matter high you’re jumping it. Unbeatable.
Rotwilds are lighter – the E+ weighs in at just 20.5kg, 7% less than it’s closest rival.
Despite having lower power batteries, the E1+’s nearest rivals are much heavier: the Haibike XDuro Nduro Pro is 22.1Kg, and the Haibike Yamaha AMT weighs in at 22.2kg.
How have Rotwild achieved this feat? The secret is in engineering nous and use of the very latest materials and production technology: The IPU bottom tube battery housing is built up using multiple uni-directional pre-impregnated carbon fiber layers of precisely defined weights, each carefully orientated to follow the load-paths generated from the hardest riding. Thickness of the carbon bottom tube is varied throughout its section – not to thin, not too thick – but just the right number of layers to achieve the maximum possible rigidity and lowest possible weight.
The IPU is formed and bonded to other fame components using the high-precision ‘closed-mold’ process (other frame makers use inferior ‘open-mold’ or ‘vac-bag’ processes). This requires over 70 individual molds to make Rotwild’s three carbon/aluminium frame types. It works: these material and process choices have delivered successes on the toughest race courses, and demonstrated clear performance advantages at the pinnacle of international competitions. Trophies galore at the Olympics Games and victory in the XC World Championships attest to the capabilities of Rotwild bikes.
Aluminium elements of the frame are equally exceptional; formed from 6066 alloy heat treated to Condition T6, this aluminum alloy is stronger and lighter than the standard 7020 T6 used by most MTB makers. It’s improved characteristics are significantly higher tensile strength (around 30 %), and much greater resistance against bending, compression, and shear loads (around 40 % greater).
In short, if you choose a Rotwild E+ Enduro you won’t be sending your frame back to us in five years riddled with fatigue fractures, but even if you did, it’d be 10% cheaper to post than any other electric mountain bike!
The Rotwild E+ is more powerful – with a whopping 90Nm on tap it has a 20% power advantage over its nearest rival.
The beating heart of a Rotwild is the peerless BROSE 2.0 Drive Unit. For 2016 the Brose has new software giving more low-speed torque and smoother power delivery across all speed ranges. Its main ingredients are aluminum, magnesium, experience, enthusiasm and …helical epicyclic gears: in just designed in Germany, its made there too.
Where other well known e-bike motors are built to a price point, the Brose 2.0 is designed and manufactured to a quality standard, incorporating precision engineered helical epicyclic gears. These are much more expensive to manufacture but offer dramatic performance and wear rate improvements over the cheaper spur gear tooth profiles that the completion use.
In the simplest terms spur gears transfer power from the driving gear to the driven gear via only one or two teeth at a time, whereas with helical gears power is transferred by three connecting teeth at a time. This results in less wear, less noise, less friction and a smaller and lighter drive unit.
Rotwild’s main rivals use either a Yamaha or Bosch motor – these are not only heavier and bulkier than the BROSE motor – for example on the Bosch unit there’s no space for a 2nd chainwheel – but they are also considerably weaker: Torque for Bosch CX unit is 75Nm and for the Bosch Performance motor its only 60Nm. The table below show the impact this has on all-important Power to Weight Ratios – The E+’s Power to Weight ratio is 30% higher than its closest rival.
Despite its small physical size the BROSE 2.0 produces a market leading 90 newton meters of torque. It does this quietly, reliably and without fuss. The company’s sensor concept is the only one of its kind on the market today: it measures rider pedal force no fewer than 420 times a second, delivering smooth, vibration free assistance. Production began in July 2014 and by August last year the Rotwild/Brose test team had covered 69’445 miles of arduous Alpine trails.
Brose Drive Technology is a division of the Brose Group, one of the most innovative and successful suppliers to the international automotive industry, employing some 22,000 employees – 2,500 of them engineers – at 57 locations in 23 countries around the world. Their annual turnover exceeds €5 billion. Last year Brose manufactured 100 million electric motors. They know what they’re doing.
Decades of experience specialising in mechatronic systems for the automotive sector mean they’re perfectly placed to produce this innovative e-bike drive unit. Development and production of the Brose e-bike motor is carried out entirely in-house at their Berlin engine plant, where a dedicated team of engineers design, build and test the system at their purpose built e-bike centre of excellence .
How do they compare?
|Haibike xDuro NDuro “Pro”
|Weight:||20.50 Kg||22.1 Kg|
|Power to Weight Ratio:||4.39 Nm/Kg||3.39 Nm/Kg|
|Silly External Idler Sprocket:
|Battery Capacity:||518 Watt Hours||500 Watt Hours|
|Charge Time:||50% 1 Hr, 100% 2.5 Hrs||50% 2 Hrs, 100% 4.5 Hrs|
|Price:||£ 5’599||£ 5’999|
Compared to its competitors (eg Haibike) Rotwild electric mountain bikes have much greater ground clearance:
The Rotwild ENDURO goes further than the rest – at least 30% further than its nearest rival.
The Li-Ion battery is integrated into the carbon fibre bottom tube, ensuring the lowest possible centre of gravity, and at 518Wh the battery will drive you further than other electric MTB in it’s class. It’s not just me! Many of our Rotwild customers have had first hand experience of the Brose’s efficiency – of course the range between re-charges on a Rotwild is greater than any of its competitors because it has a higher capacity battery, but that does not explain how a Rotwild with 20% more power than its rivals can run flat out at Cannock Chase from 11am to 6pm, stopping only for a coffee in the morning and a single pint in the afternoon on one charge. Clearly, most of the range advantage is down to the efficiency of the Brose drive unit.
MTB ledgend Richie Schley shows how to do it on a ROTWILD:
In Late January we visited Rotwild’s design and production center in Frankfurt where the team showed off the cutting-edge design manufacturing processes behind the range of Rotwild electric mountain bikes. Here are some photos we took, for full size images please click this About Rotwild link.
- IPU – Integrated Power Unit with ROTWILD Power Pack and Brose Power Engine
- Carbon Downtube with integrated battery
- Aluminium 6066 T6 – CHANNEL Hydroforming XC Tubeshape
- XCS – CROSS COUNTRY Suspension system // Travel 135mm
- FOX FLOAT CTD FACTORY KASHIMAAdjustable trail mode CTD – Climb-Trail-DescendTrail adjust tuning Range / Rebound / Boost Valve Technology / 7.875×2.0″
- RHS 15 – Integrated stainless steel headset 1.5“ / Tapered / Ti Coating
- BB92 Press Fit – Integrated bottom bracket
- Brake post mount 180mm
- Exchangeable drop out inlays MDI2 / Direct Mount
- 142-12mm RWS Thru Axle
- Internal cable routing for remote seat post
|DÄMPER||FOX FLOAT X 3-POS EVOL LSC FACTORY KASHIMA|
|HEADSET||ROTWILD RHS 15 TI|
|FORK||FOX 36 FLOAT 170 FIT4 LSC FACTORY KASHIMA|
|BAR||CRANKBROTHERS COBALT2 780MM|
|SEAT POST||KINDSHOCK LEV INTEGRA Ø31.6MM REMOTE 150MM|
|SEAT||ERGON SME30 RW|
|DRIVE UNIT||BROSE 2.0|
|BATTERY||ROTWILD POWER PACK 4P10S|
|CRANK||E13 TRS+ ISIS 36T.|
|SHIFTER||SSHIMANO XT INTEGRATED|
|REAR DERAILLEUR||SHIMANO XT-11 GS DM PLUS|
|CASSETTE||SHIMANO XT 11-42T.|
|BRAKE||SHIMANO XT FIN PAD|
SHIMANO RT86 ICE 203/180
|WHEELSET||DT SWISS E1700 SPLINE TWO 15/12 RWS|
|TIRE||CONTINENTAL TRAIL KING PERFORMANCE 27.5×2.40|
|FRAME COLOUR||BLACK MATT/BLUE|
Specifications correct at product launch date and may vary during production year.
|A||SEAT TUBE LENGTH||(mm)||440||460|
|B||TOP TUBE LENGTH||(mm)||590||615|
|C||HEAD TUBE LENGTH||(mm)||120||125|
|D||CHAIN STAY LENGTH||(mm)||455|
|F||HEAD TUBE ANGLE||( ° )||66,0|
|G||SEAT TUBE ANGLE||( ° )||74,0|
Here are some videos ROTWILD have produced to show how their electric bike technology works, and how it beats the competition:
Here are some videos showing the partnership between Mercedes-AMG and ROTWILD:
And finally, here are some of the clever folk that make and ride ROTWILD MTBs:
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