Riese and Müller are the German engineers behind the eponymous company; Markus and Heiko certainly have their own trademarks when it comes to bike design and they are all here in this incredibly tough off-road model, from the super strong frame construction to the many practical features such as dual racks and dual in-frame batteries as standard.

Riese and Müller’s e-bikes aren’t for weight weenies, but that’s because they prioritise practicality, comfort and safety above all else. There is still a strong sporty element to many of them, including the Supercharger range, and that means a power-packed, exciting ride too. The test bike, the dual battery Supercharger GX Rohloff is a case in point, tipping my digital scales at 30.77kg including batteries (each battery contributes 2.89kg). However, once you are on the bike the kilos melt away, as Bosch’s most powerful mid-drive, the Performance Line CX provides more than enough assistance to compensate for the heavier than average bike weight and the design’s comfort, stability and practicality come into their own.

In addition to the Supercharger’s strong frame – rated for 140kg of rider and luggage – which hides 1000Wh of battery power as standard, you also get an impressive spec: Suntour Aion air forks, Rohloff Speedhub E14 hub gears, Gates belt drive, rear rack and small front parcel rack, ABUS folding lock, Busch & Müller Lumotec IQ-X E lighting, Cane Creek Thudbuster seatpost suspension, mudguards and kickstand.

Off-road riding in comfort

Whilst it’s clearly not a full on e-mtb, the Supercharger will tackle all kinds of trail and certainly it’s well up to more than just the usual tag applied to many hybrid bikes as being ‘suitable for canal towpaths and forest tracks’; in fact the combination of sure-footed handling, smooth, high-quality adjustable 100mm front suspension and the excellently grippy Schwalbe Rock Razor tyres means this is a bike that will roll over most off-road surfaces except very thick mud and large rocky drop-offs. The tyres also felt pretty free-rolling and cornered nicely on tarmac, despite how knobbly they are.  

The combination of Rohloff’s E-14 electronically shifting hub and the Gates belt drive gives a huge 526% percent gear range, again enough for just about any task on any incline you would want to throw at it. Of course, this adds weight compared to a derailleur set up but this version is about low maintenance and indestructibility. There's a derailleur version of the Supercharger too.

Electronic gear shifting is achieved via buttons near the right bar grip and takes only a fifth of a second, though you still need to back off the pedal power to stop some complaining graunching noises. Multi-shift mode simultaneously shifts 3 gears in a single sequence and auto-downshift function means you are always in a low gear to start riding again once you have stopped.

All these attributes were put to good effect over a weekend of light touring across the Dark Peak area of the Peak District National Park, passing Kinder Scout and heading along Rushup Edge and over Cut Gate. The E-MTB power mode particularly comes in handy for that kind of riding, with power kicking in where needed but dropping out to save battery power on flatter sections under gentler pedalling conditions. The many rocky and muddy sections mean I would have opted to go tubeless (rims and tyres are tubeless ready), for the ability run at very low pressure without punctures and get a bit more grip. Overall though, the bike stood up to everything the Dark Peak could throw at it.    

Meet the high-tech Kiox display

I was pretty excited to try out the Kiox display too; other display options on the Supercharger are the Intuiva and the COBI smartphone holder style system, though the latter is not available in speed pedelec and Rohloff models. This full colour, minimalist display adds functions compared to other Bosch options, the Purion and Intuiva, and removes quickly and easily via a magnetic connection (also designed to stop damage to the unit in the event of heavy crash).

It’s clear and crisp from a variety of viewing angles, though you’ll need pretty sharp eyesight to read some of the smaller text and graphics across the top of the screen. It also features scratch resistant Gorilla glass.

The extra functionality offered by the Kiox looks to be aimed at sportier riders, as indeed Bosch have stated, and includes displays showing watts (human output only, so ideal for fitness riders wanting to measure their own input) and heart rate. You just need a Bluetooth compatible heart-rate strap to use it; I tested it and connectivity was easy and quick and it worked well. Bosch is still working on more software to take full advantage of features such as smartphone connectivity and the unit’s GPS functions. The Kiox also has a USB port (USB 3.0 compatible) for charging devices and for firmware updates.

Still, my early version of the Kiox looked impressive and was pretty easy to use via the 5-button handlebar control by the left handlebar. The black buttons could have been a little easier to find with thick gloves on (maybe raising the profile of buttons more or adding a coloured outline to each one would help), but that’s my only quibble on what looks to be, at last, a display that has the potential to take full advantage of all the digital technology out there.

I particularly liked the watts display and used it both to keep any eye on my own power output. The novel circular graphic that displays which power mode you are in also has two shades of the appropriate colour (green = eco, blur = tour, purple = emtb, red = turbo) so that you can always see at a glance the proportion of your (human) power as compared to the proportion of electric motor power. Clever stuff and ideal for those who want to use maximise their own pedalling effort and get more exercise.

Big, big battery capacity

The double battery means there’s enough power capacity on board for the most demanding of trips. I did a rough calculation based on my usual testing ground of steep Pennine climbing on quality bridleways and tarmac, and came up with a guestimate range (in blustery winter conditions) of 50-100 miles.

So, Riese and Müller are clearly aiming the Supercharger at pretty serious e-bike riders, those who want to be able to carry a good load and ride all day long, off-road if they so choose. Bosch’s dual battery system itself has advantages over just carrying a spare battery. Clearly you don’t have to stop and get off to change a battery. More than this though, the system draws from both batteries equally as you go along. So, for example if you use 500Wh of power on a ride you started with fully charged batteries, you will end up with approximately 250Wh remaining in each battery. This is kinder to the batteries and should prolong their lives, as their fully charged and discharged states will be reached less often, and reaching these extremes is one factor that can hasten battery decline.     

The Powertube design means the batteries remain well-protected both from damage and weather within the bike frame and the two stage ‘key and push button’ removal is thoughtfully designed to stop them being damaged from falling out of the frame. The 6-amp fastcharger means you can recharge both batteries from empty in around six hours (or around two and a half hours for a half charge).

Options and price

There are various other Supercharger models, including speed pedelec (HS) and Vario variants, the latter with continuously variable transmission which adds weight and some inefficiency but also gives very easy and intuitive shifting.  

This would make a great off-road tourer for long distance trips, with the huge battery capacity allowing for long days in the saddle and the low maintenance, extremely tough Rohloff hub gears meaning you can get on the with the riding whatever the conditions under your wheels. If you want a single battery option, check out R&M’s Charger options.

At more than twice the price of many other single battery e-bikes it is of course a very big price tag. This is partly offset by the dual battery and all the extra equipment, but also the fact that this is a once-in-a-lifetime purchase that should give lifetime enjoyment.

Website: www.r-m.de/en

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