Bicycles

SEM looks to bring monster 4,000-watt dual-drive e-mountainbike to US

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Italian company SEM is looking for ways to bring its 4-kW, dual-drive Moto Bike to the United States
SEM Mechanical Prototypes
Separate left-side chain drive for the 4-kW mid-drive motor
SEM Mechanical Prototypes
The SEM prototype crashing through the bush
SEM Mechanical Prototypes
With that much power behind you, uphills and jumps will be epic
SEM Mechanical Prototypes
Powerful and lightweight, with dual suspension
SEM Mechanical Prototypes
Sturdy aluminum frame
SEM Mechanical Prototypes
Left side drive can be specified with chain or belt drive
SEM Mechanical Prototypes
Italian company SEM is looking for ways to bring its 4-kW, dual-drive Moto Bike to the United States
SEM Mechanical Prototypes
Built for hardcore off-road e-biking
SEM Mechanical Prototypes
Regular crank and gearset on the right
SEM Mechanical Prototypes
Meaty full-length suspension forks
SEM Mechanical Prototypes
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This mud-flinging off-road monster is a prototype by an Italian company, SEM, that's looking to do some business in the USA. With its massive grunt and interesting double drive system, it would be an absolute brute on the trails.

Named the "Moto-Bike" – and it might as well be a small dirtbike – this thing uses a strong aluminum e-mtb frame with an integrated 4-kW motor and a big ol' 52-V, 17.5-Ah battery capable of storing around 910 watt-hours of energy.

On the right side of the bike, there's a standard 11-speed mountain bike gearset. On the left side, there's a belt drive straight back from the motor to the back wheel, thus neatly avoiding the tendency powerful mid-drive e-bikes can have of chewing out your chains and sprockets, at the cost of a little extra complexity. Personally I think it's a great idea, even if it means the motor no longer runs through the gears.

Left side drive can be specified with chain or belt drive
SEM Mechanical Prototypes

Range is rated around 50 km (30 miles), although you could realistically expect well more than double that if you went easy on the throttle. It rocks a regenerative braking system, which are rare on e-bikes thus far, and it'd be interesting to see just how much that kind of thing could put back into the battery, especially on big downhill sections.

There are disc brakes and suspension front and back; the forks are full-length ground pounders that look like they could take some proper jumping. This thing's built for serious, hardcore trail work, however much you might want to use it to wheelie your way to work.

The SEM prototype crashing through the bush
SEM Mechanical Prototypes

SEM is hoping to get a few of these into American bike shops, and is looking for collaborations to help take things further. We haven't seen any pricing information, but at this level of specification you're probably talking small dirtbike money.

Source: SEM

View gallery - 10 images
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8 comments
guzmanchinky
Looks AMAZING! But the problem is that unless it's a Class 1, it's totally illegal pretty much everywhere in the US except trails designated for off road motorcycles.
Jim E
So, an electric motorcycle with a crankset?
Mzungu_Mkubwa
Making the belt drive axle co-linear with the swingarm pivot is good design. No need to worry about tension issues over the path of suspension travel there. Pricing likely to be well north of a Sur-Ron lite-bee, but looks to be more capable, too, maybe, if not as powerful...?
ljaques
4kW sounds like a lot of fun. I like the belt drive and pedals for the times you want to cruise on your own or just to get home after running the battery flat. But it's the price of these things that kills the sales. Stealth was getting $12k+ with no crank set. The illegality on most Western country's roads is a minus, too. I still want Zero to put out a half-powered FX and sell it cheap.
Thud
I remember riding my Schwinn Collegiate back in the 70's and wondering why I had a hard time keeping up with the guys on the European bikes. This Electric bike weighs 32 lbs. I just looked up the specs on the Collegiate... 39 lbs. Lol.
Gannet
There was me thinking dual drive meant both wheels. Oh well, I'm sure a front e-hub will be available at some stage.
Mac Sinclair
This thing would be seriously bad news for the e mountain bike sport

It’s aggressive dangerous for pedestrians which is why it’s illegal

As it is right now I can ride my perfectly powerful enough Specialized Turbo Levo Comp with its 90nm motor and 700 watt battery anywhere I can ride a normal bike without attracting any negative attention, so on bike parks and off road on all the Lake District’s mountain trails

This is a bike for bell ends that would quickly see access rights overturned
Grunchy
4000 watts is like 5.3 hp.
Whee. Watch out, it’s a widow maker.