A friend just sent me a link to this new E-bike, from Surain in Belgium (near the northern border of France). Sooner or later, this interesting off-road E-bike will be compared to a Stealth Fighter, and we will be looking for information about the details to see how it stacks up. These guys are familiar with the level of performance needed to make an E-bike significant, because they also make an electric motorcycle.
They are off to a good start by using 72V. It is the amps that generates the most heat in the motor and controller, so engineering-wise, it is always good to start out with the most volts that will work for your design. The controller is a significant 18-FET, so although Surain is claiming it can handle 60A peaks, the majority of the time you will be using fewer amps than that, so a large 18-FET should run fairly cool enough to avoid overheating in most conditions.
They are drawing 60A peaks from a 15-Ah battery, and this is the only thing that might cause me some concern. They don’t list the battery chemistry or cell type…only that the cells are from Panasonic (which is at least one good sign). It might be using high current NON-LiPo chemistries and cells, and I hope that their battery uses one of those.
An interesting feature that I noticed is that they list their frame as being made from a very strong 7075-T6 Aluminum alloy, But a close inspection of the pictures show that there seems to be very few welds. The separate pieces that make up the custom frame appear to be made from water-jetted aluminum plates, and then bolted or riveted together.
Crystalyte Rear hub 2.5-Kw,
Battery: 72V / 15-Ah, Panasonic cells
Controller: 18-FET, 60A
Fork: Rock Shox Boxxer
Rear shock: RockShox Kage 240mm
Brakes: Hope dual piston discs, 203 mm front, 203 mm rear
Front tire: 26″/ Rear tire: 24″
Speed: 60 km/h, (37-MPH)
Frame: 7075 T6 Aluminum
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The pic below is also from Surain. It claims to be a pic of their “Baron” model, but I’m having a difficult time seeing any bike (*wink).
The Baron uses a 36V / 15A battery (using Panasonic cells), and the controller is a 350W, 6-FET, 20A unit. Its top speed is 25 km/h (15-MPH)
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Sulain also makes an electric motorcycle. The street-legal model is the “RVs“, and the same E-moto as an off-road version is the “VRX“.
Both models use the same power system: the battery is a KOKAM 48V / 40-Ah, and the controller is an Alltrax 400A, and it has a top-spedd of 85 km/h (52-MPH).
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Here is a pic of a high-concept show EV from Surain, named the “Eol“. The drop-outs are steel, and the rest of the frame is aluminum, using a water-jetted plates and bolts construction. This might be the “scooter” that their website states they will have in production soon?…
Here is an interview with Benjamin Surain (for those readers who can speak French!)

The Surain company logo. I couldn’t help but notice that the capital “S” has an angels halo and also a devils tail…
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Written by Ron/Spinningmagnets, February 2014
If you are ever in south west Belgium, here is their address:
Rue de l’Innovation, 7-3
Froyennes 7503
Tournai, Belgium