I'm a little disappointed to see this concept as a toy rather than a functional mode of short range transport.

So you charge the bike for 4-6 hours, drive out to the course and then you get maybe 35 minutes of riding time? The batteries better be removable and cheap to buy spares because you'd need to carry 8-16 of them to have a good day of riding.

Yeah no emmisions! lol

What about all the coal thats burnt to produce the electricity to charge it. This is possibly worse for the enviroment then a normal petrol bike because we are talking about 2 changes in energy state, fuel to electricity, electricity to motion. A normal bike simply requires the fuel to motion change in energy state. Remember everytime you make a change in energy state you lose a lot of energy.

Of course if you live somewhere powered by a nuclear power station then you might be actually getting somewhere enviromentally wise.

It's not quite that simple, Shaun.

Even in cars a lot of the energy contained in gasoline is lost as heat and sound - the efficiency is in the 20-30% range.

In a dirtbike, it can be expected that even more of that energy is lost, and I doubt that emission control is very advanced, not to mention the noise that can be very disturbing to the faun in a forest.

As for where the electricity comes from, it is often possible to buy from a "green" utility even in places where coal is used, and a lot of other places use hydro. It is also possible to charge the bike at night when the energy produced by coal plants would be lost anyway (because they are to slow to start and stop so they can't follow demand).

Many factors..

In small systems most energy loss occurs via surface area but volume goes up as the cube of the size while surface area only goes up as the square of the size. Meaning volume increases rapidly with size, keeping more energy in the machine doing work instead of escaping into the environment as waste.

For electricity the delivery loss has been calculated at 7% (in the US) while we actually burn 20% of our oil just turning it into gasoline and distributing it to all the stations.

Once power gets to the cars, electric loses another 10-15% (not counting regenerative breaking gains) vs an additional loss of 80% for gasoline.

The reason why this isn't immediately obvious is that gasoline has 45MJ of energy per kilogram while most batteries have less than 1! Some experimental batteries have reached 8MJ/kg but they're not mass market yet.

Forget this thing. Too much cheap plastic and metal, making it weigh too much.

I'd much rather mount two of these (back and FRONT) on an old mountan bike and see how much fun an all-wheel-drive dirt bike can be!

Carl

I completely agree. I have been considering buying this Bionx electric bike system for several months. In about half a year I will need to start commuting to a town some 25 kilometers away from my location two or three times a week. There is no regular public transport from my nearest town to the other one, and I really don't want to use a car. My ideal solution is a really good, relatively fast electric bike system at the best price. The best combination of power, speed, features, quality and price that I have seen so far is this Bionx system. And now that I checked Carl's link, I see the Bionx has gotten even better. Thanks Carl.

i need abike

Energy is pretty complicated, but huge amounts of electricity are used to run coal-burning power plants--even oil refineries. Much of this electricity is surplus nighttime power that the US DOE recently estimated could power millions of electric vehicles. Every evening we're sitting on a huge, untapped renewable resource.

The MUD-E listed here is a smaller, low-powered electric design for younger riders. Parents have said it is an ideal first dirt bike.

this isnt very good it goes pretty slow and takes along time to charge for a short riding time, that means you cant take it to the track and ride all day, how boring