Segway inventor drives off cliff

[c1ue]

Re: Look What The Segway Begat...

I think you missed the point about the limited velocities that can be achieved in ever more crowded urban environments.

And I think the formula you want is Newton's second law of motion [F=ma], not Boyle's Law. ;-)

No, because even at 20 mph, the law of conservation of momentum - which is what governs the energy distribution in an impact - dictates the Super Segway goes flying off at 120 mph. More than enough to kill (equivalent to 2 equal weight cars each driving 60 mph having a head on collision).

And yes, it should have been m1v1 = m2v2 - or P1 = P2.

The point was simple: why does this super Segway have to be so large? Only because it is intended to drive on the road with the big boys.

The extra mass is waste: both in materials and in energy.

[GRG55]

Re: Look What The Segway Begat...

...The point was simple: why does this super Segway have to be so large? Only because it is intended to drive on the road with the big boys.

The extra mass is waste: both in materials and in energy.

I think your conclusion is completely off base and unsupportable in this instance. THere's only three of these things running at the Shanghai 2010 fair. They are all in a closed environment where the only thing they can hit is one another. To suggest that they weigh what they do because they are "intended to drive on the road with the big boys" is utterly illogical. They could well weigh what they do because they carry a lot of batteries because they have to run continuously all day in front of the public. They could weigh what they do because there are only three of them, likely hand built, and no serious effort was made towards materials and component optimization. They could weigh what they do because existing components from the GM or Shanghai Automotive's parts bins were used to keep the cost and time to completion reasonable.

They are an experiment...as much a design and technology integration exercise as anything else.

I think the current crop of hybrids and electric cars, like the Prius and Volt, are a complete waste of time. The EN-V is the first thing I've seen that might lead to something that actually makes some sense as an electrically powered automobile. If it does, the final result might weigh half as much, or twice as much...too damn early to know.

You are grasping at very thin straws with your arguments above C1ue.

Finally, for all you bicycle and scooter advocates out there...the Chinese and the Indians [and a whole lot of others] are dumping their bicycles for scooters...and then their scooters for automobiles. Arguing that the answer lies in going back to some form of tandem two-wheeler might be compelling...but it ain't gonna happen. So we best figure out how we're going to avoid repeating the American experience of congested cities in the developing world, accepting the fact the cars are going to increase in numbers.

[GRG55]

Re: Look What The Segway Begat...

No, because even at 20 mph, the law of conservation of momentum - which is what governs the energy distribution in an impact - dictates the Super Segway goes flying off at 120 mph. More than enough to kill (equivalent to 2 equal weight cars each driving 60 mph having a head on collision)...

I shudder to think what the result would be with your Goped...

[c1ue]

Re: Look What The Segway Begat...

They could well weigh what they do because they carry a lot of batteries because they have to run continuously all day in front of the public.

They weigh so much because the gadgetry necessary to balance the unwieldy 2 passenger mess is heavy - which in turn requires more battery and braking power - which in turn increases the weight and lessens performance.

As a pilot surely you realize the weight vs. power tradeoff.

Furthermore the range is crap - shorter than the range I get on my 43 lb/19.5 kg Goped:

http://media.gm.com/content/autoshow...10/March/env02

Top Speed: 40 km/h [25 mph]


Range: 40 km [25 miles]


Energy Consumption: 70 Wh/km [125 Wh/mile]

Yes, its top speed is slightly higher (25 vs. 20), but I could achieve 30 mph with a larger motor as well. And the range on my Goped drops from 28 miles to about 16 at top speed.

Even the specification above looks like a load of bull***t: my Goped has 32 Ampere-hours of capacity with a 1000 watt motor. The batteries are 25.9V - hence 829 watt-hours.

The supposed Super Segway's power usage of 70 Wh per km times its range of 40 km = 2800 Watt hours.

20 times the weight, same speed, and only 3.4x the power? Yeah right.

Even adding in a 170 lb rider this seems ridiculous: 213 lbs. vs. 1050 lbs = 4.9x weight differential.

I shudder to think what the result would be with your Goped...

You would be right, except my Goped never goes on the road - I ride on the sidewalk and act as a pedestrian (i.e. if the way is blocked by people walking slow in a line abreast, I step down and walk behind them. The Goped is further fully capable of going just a walking speed, as well as taking the corners on the sidewalk.

This path isn't feasible for the Super Segway. It is simply too large for anything but the road.

Then let's talk cost: even if the 3.4x power increase is correct (and I strongly doubt that it is), the battery packs on my Goped cost $500 each, and there are 4 of them.

$6800 just for the battery packs. You're talking $12K minmum for the machine.

It would be cheaper to have buses or even http://www.citycarshare.org/