50mph pedal bike

[Wiglaf]

Math is broken!

Just buy this instead: http://derringercycles.com/bikes.htm

sweet bike. what do those cost?

This electric bike is kinda silly.. can't I just use a regular throttle if I'm going to cruise 50mph on battery juice?
I don't like that it's trying to hide the whole part about needing to charge it up if you expect the electric assist.

[ACMF74]

needs to be cheaper, but this is the simple answer to in city transportation. Fuck prius/hybrid cars that require those fucking huge ass batterys.

+1

[Bavarian3]

Math is broken!

Just buy this instead: http://derringercycles.com/bikes.htm

[Slangbox]

Watch the vid, this particular bike is different. There is no gas motor, just an electric one powered by pedaling.

Ohhhhh my god...

For $40,000, you get electric, or for $300, you get gas. Hmmm...

New technology has to start somewhere. I think it is a really cool idea.

[Paukert11]

I rather pick gas!

[Beach Bum]

Watch the vid, this particular bike is different. There is no gas motor, just an electric one powered by pedaling.

For $40,000, you get electric, or for $300, you get gas. Hmmm...

Haven't watched it yet, but you can alreayd buy a motor and mount it to a bike frame and get about 40MPH out of it and about 70 miles of range for ~300$

Watch the vid, this particular bike is different. There is no gas motor, just an electric one powered by pedaling.

[Moto-Mucci]

Pg.6: "It's a perpetual motion machine."

Let me know when they make one with a battery operated pedaling machine attachment.

Otherwise I'll take a Puch Magnum Cafe Racer for <$1k.

[Slangbox]

It's got a battery. This force multiplication crap is nonsense. Go look at the PDF on ErockIT.net.

Thank you for finding that. I rest my case. The pedaling is to "give the impression of supernatural powers" (PDF, pg.5). 40k to play superman.

[Beach Bum]

It's got a battery. This force multiplication crap is nonsense. Go look at the PDF on ErockIT.net.

[Slangbox]

I would assume it transfers the energy you pedal into something more useful like 50x torque. google search and a genius you can become.

I don't think so. Pedals+generator+battery+electric motor does not equal greater potential work (Force x distance). As in, the same amount of pedaling (work in) can only induce the same amount of work out. Yes, you could use the electric motor to boost the accelerating power (and power to fight friction during higher constant speed) of your pedaling, but you could not travel as far. It'd just be like down-shifting on a 10-speed.

For example, if a regular bike is traveling at 4km/h and the force of friction (internal+wind resistance) is, say, 4N, and it travels 1km, It has done 4000Nm of work. But if it is traveling twice as fast, the force of friction is likely to be more than 4 times as much (since wind resistance is exponential) and thus around 16N. Thus, traveling 1km at 8km/hr would require 16000Nm of work.

Therefore, to maintain a constant speed higher than the constant speed attainable by pedal power alone, there must be an alternate source of work in (a pre-charged battery). So again I say, the pedaling is just helping you use the electricity slower and increase your range. But you will run out of excess electricity eventually, and at that point you're pedaling a really heavy bike. A really heavy 40k bike.

[/fucking nerdiness]

If I've made a mistake, which is more than likely since I haven't been in physics for a month now and haven't studied it in more than 4, please inform me. I'm not trying to be an ass, I just got started and couldn't stop :-(

Edit: I predict, with my crystal ball, a "TLDR"

[Beach Bum]

I really do want to know the science behind it. I am intrigued.

[Wh33lhop]

Haven't watched it yet, but you can alreayd buy a motor and mount it to a bike frame and get about 40MPH out of it and about 70 miles of range for ~300$

But you can't make the speed governed by how fast you pedal, for mad gangster status yo.

[Kruzen]

Haven't watched it yet, but you can alreayd buy a motor and mount it to a bike frame and get about 40MPH out of it and about 70 miles of range for ~300$