Archives

I saw something that got my attention - maybe one day it will be a more viable option for me and others.

My work commute is 25 miles - 21 or so of it freeway. At 70mpg, that's about 3.5gallons a week for work commutes. There is a way to maybe to it with no gas at all.

http://www.cleanmpg.com/photos/data/500/twike.jpg
In Europe, the Swiss have developed a human-powered hybrid called the Twike (http://en.wikipedia.org/wiki/Twike). It is basically a recumbrant bike that allows two to ride side-by-side. Pedaling is optional but it extends the range - powered by either nickel cadimum or NiMH batteries that take 2-3 hours to charge. It runs EV all the time, but the riders can "assist" by pedaling. Top speed is 53mph, although some have reported speeds of 65mph. It weighs 542 pounds and in the US is legally considered a motorcycle. Pedaling does not significantly increase the speed, and a computer regulates the battery.

Getting to work in the morning is about 35 minutes, so it would be quite a workout - I'd need to stop by the gym to borrow the showers. :D Maximum range is 140miles, so I'd need about nine pitstops and a bunch of powdered Gatorade to drive from Dallas to Madison for HybridFest 2007. :eek:

Cost would be a problem - my 2000 Honda Insight with A/C cost 23K, but the basic Twike is 26K - the pull no punches one in the Needless Markups catalog (http://en.wikipedia.org/wiki/Twike) is 40K. :eek:

Would love for something like this to be around 10K - my commute would be my workout.

Hi Chuck:

___There was an interesting article over at EVWorld a few months back on the Twike. Sorry I do not have a link but IIRC, it was an interview w/ an owner who also sold them here in the states? The discussion went into the history and of course the Twikes capabilities. My only gripe is the cost of course. In todays world, everything comes down to economics but just wait a few years. I don’t know if you can find a route to keep you off the Dallas area Interstates but if you can, a HyMotion Prius II PHEV-20 below 34 mph would do the trick today and stripped 07 Prius II’s can be picked up for < $20K w/ the tax credit applied. I really hope the 09 - 11 Prius III has a PHEV option because if it does, oh boy :D

___Good Luck

___Wayne

There's been a lot of interest in electric-assist bikes around
events like Tour de Sol -- now that the technology is getting
there and the batteries aren't so heavy, they're quite viable.
A guy did the entire 200 mile MPG loop at TdS last spring on
one, turning in a time that wasn't all that far behind the cars.
[I'm not sure if he rode on the interstate, though, but he went
about the same distance.]
.
If the human-in-good-shape provides 200 watts and an electric
system provides a few hundred more, the net effect can be a lot
of distance covered. Air resistance, of course, is the biggest
enemy.
.
_H*

If the human-in-good-shape provides 200 watts and an electric
system provides a few hundred more, the net effect can be a lot
of distance covered. Air resistance, of course, is the biggest
enemy.
.
_H*

200 watts for a human is probably optimistic; 100-150 watts is a more reasonable estimate for any length of time. I train a lot (1-2 hours a day on the rowing machine). I can manage 250-300watts flat out but maintaining 200 watts is tough. I think I've done 240 for 8 minutes and that put me well into the anaerobic zone. I can manage 150-ish for an hour.

Before incorporating 200w into any calculations, it would be a good idea to hop on a rowing machine at a gym and try rowing at 200w. I think you'll see what I mean.

John

http://www.onlinebikecoach.com/images/hp-plate.gif

This would be my license plate of choice. :D

No, I don't have Lance's power - not even Floyd Landis' and his "assist" (i.e. doping). :embarassed:

It would be interesting to get an idea of what a person's VO2 Max (http://en.wikipedia.org/wiki/Vo2_max) (heart/lung capacity) needs to be to generate 200 watts. Average man 0 40. I was at 59 once, but probably down to 50. Lance - 85. Some elite cross-country skiiers has done 92 or 93.

[QUOTE=Delta Flyer

It would be interesting to get an idea of what a person's VO2 Max (heart/lung capacity) needs to be to generate 200 watts. Average man 0 40. I was at 59 once, but probably down to 50. Lance - 85. Some elite cross-country skiiers has done 92 or 93.[QUOTE]

The VO2 Max will give the MAXIMUM rate at which the individul can take in and process oxygen. Someone with a greater VO2 max can, on average, probably generate a greater sustained output, but that output will NOT be at their max.

What we need is a figure for the output that can be SUSTAINED for say 30 minutes (or whatever the commute time is) twice a day.

As I said I can generate 250-300 watts max but there's no way I can sustain that for long.

Try it on a rowing machine in the gym, or any machine with a watts display that uses mostly legs, like bicycling.

I did pick the wrong fittness measuring stick - VO2 Max is a peak figure.

It would be good to get a realistic idea of how much of the load a fit person could provide in a vehicle such as a Twike.

Do I smell an interactive display at HF 07?

Randall

I based that figure on my own warmup on ellipticals at the gym,
the older LifeFitness units measure in watts [and they've taken
that AWAY on the newer ones, grrrr] and I found that using arms
*and* legs I could sustain 200 - 250 for the ten or fifteen
minutes I do to warm up for other stuff. Probably not half an
hour, though. In a burst I could maybe top 300 but that doesn't
last long.
.
However, it was enough to start realizing the idiotic amounts
of power and energy we've come to take for granted at the mere
touch of a footpedal. When I reel off my description of what
those little "50 Wh" video-game green cars mean in the Prius
display, it makes them stop and think.
.
_H*

I based that figure on my own warmup on ellipticals at the gym,
the older LifeFitness units measure in watts [and they've taken
that AWAY on the newer ones, grrrr] and I found that using arms
*and* legs I could sustain 200 - 250 for the ten or fifteen
minutes I do to warm up for other stuff. Probably not half an
hour, though. In a burst I could maybe top 300 but that doesn't
last long.
.
However, it was enough to start realizing the idiotic amounts
of power and energy we've come to take for granted at the mere
touch of a footpedal. When I reel off my description of what
those little "50 Wh" video-game green cars mean in the Prius
display, it makes them stop and think.
.
_H*

Excellent point on human endurance - hobbit.

I see a strong corrlation of the human body to a hybrid. The human body can run for a very long time at 80% or less of capacity (aerobic). Working harder than that, the heart and lungs can't sustain that effort, so fatigue sets in after 2-3 minutes. This is the anerobic mode - analogous to going full throttle on a hybrid and running the battery down (at least with the Insight 5-speed).

The San Francisco SPCA was created in 1868 in part because riders mistreated their horses. Aggressive driving must have dated back to the 1800s and earlier. :eek:

OK, I have data. Today's schedule called for 80 minutes on the rowing machine at a moderate heart rate, with 10-stroke bursts every 7 minutes. Average output for the whole thing was 141 watts, surprisingly close to my guess. Peak output for the 10-stroke bursts was 360-380 watts, which shocked me.

This is for a moderately fit 60-year old guy. Fit younger guys could probably do more; less fit people probably somewhat less. It would be interesting to know how much more and less. Obviously there are exceptions, but women ON AVERAGE have lower wattage outputs than men do. Design of a human-assisted vehicle would have to take into account the target customer population as well as the length of the trips envisoned.

For a human-assisted vehicle I'd guess you'd have to figure somewhere around 100-200watts from the human on a sustainable level.

But sort of analagous to hybrid cars, people have recuperative powers, which is one of the reasons bicycles work so well. People can put out higher wattages for short periods of time and then recuperate on a downhill (or in a draft in a race). It's not exactly recouping energy via regenerative braking, but it's somewhat analogous. So this should be factored into human-assisted vehicle design.

....But sort of analagous to hybrid cars, people have recuperative powers, which is one of the reasons bicycles work so well. People can put out higher wattages for short periods of time and then recuperate on a downhill (or in a draft in a race). It's not exactly recouping energy via regenerative braking, but it's somewhat analogous. So this should be factored into human-assisted vehicle design.

I contend the IMA hybrid system works a lot like a runner. I don't know the Prius, but it seems like a closer fit would be to a cyclist.

Hi Chuck:

___What about a much simpler E-Bike with the proper clothing or canopy for $3K or less vs. a Twike at almost 10X’s the price?

___Good Luck

___Wayne

Hi Chuck:

___What about a much simpler E-Bike with the proper clothing or canopy for $3K or less vs. a Twike at almost 10X’s the price?

___Good Luck

___Wayne

Not really up to speed on this, but legally e-bikes can't go over 20mph. :(