Breakthrough e-bike design. Well, maybe not...

Ok... It's not an e-bike but maybe it can give you guys some ideas for outrunner motors. No need to reduce the rpms! LOL :lol:

http://qconlineauction.com/site/view_ad.php?v=237916

I hope no one flips over the bars on that one! Would be easy with all the weight up front.

LOL

Freakin' awesome. Reminds me of the time I tried a battery powered leaf blower pointed behind me.

I just noticed this quote too: "you cant get in trouble riding it around on the road in my neighbor so id call it street legal". Too funny.

It might be nice having twin motors on the back positioned so the air-flow wouldn't interfere with another "part" of the bike(including the rider), that way self-defeating air resistance wouldn't hurt the useful force the motor provides.

I kind of wonder what the energy efficiency of a propeller based motor system is, assuming optimal placement and propellers. It seems like it could operate at "top efficiency"(or close to there) no matter the velocity of the bike which would seem to be an immediate advantage. Another advantage would be it could be electrified by that 6 HP outrunner(or similar) and part of the air flow being generated could be used to self-cool the outrunner engine(Which is probably the way it was designed for being made for air-planes and the such) which is a significant problem with non-cooled outrunners. Another advantage is the obvious simplicity of it and low maintenance.

Methinks someone is eventually going to try this idea.

Even if the total conversion efficiency is 75%, 75% of 12 HP is 9 HP. That's some serious acceleration and speed. 8)

A quick http://www.kreuzotter.de/english/espeed.htm calculation puts an estimate of 50-60 mph. Now, if this idea might be so awesome, why hasn't it been exploited by motorcycles? Oh... that's right... the history of batteries and the kind of machinery needed to power propellers with gas. It could also have something to do with the power needed by ICE motorcycles and how the amount of suction created by that much power would seriously interfere with the enjoyability of the ride(And possibly drag down the efficiency factor with higher power requirements/suction).

I *really* want to try this. But, alas, not enough money. *sigh*

swbluto said:

Now, if this idea might be so awesome, why hasn't it been exploited by motorcycles? Oh... that's right... the history of batteries and the kind of machinery needed to power propellers with gas. It could also have something to do with the power needed by ICE motorcycles and how the amount of suction created by that much power would seriously interfere with the enjoyability of the ride(And possibly drag down the efficiency factor with higher power requirements).

Click to expand...

And possibly that someone has tried it and accidentally touched the propeller.

EDIT: 100MW mark. This deserves cake.

[youtube]Y6ljFaKRTrI[/youtube]

Link said:

And possibly that someone has tried it and accidentally touched the propeller.

Click to expand...

Oh well. Sometimes sacrifices needed to be made for improvement.

Mao thought so, anyways.

(I think the use of a propeller cage would be... needed... which would increase the air-resistance but I don't think it should hurt the efficiency too much.)

I use to have a para plane . i had the chute off and was playing around with it on the road. I just did not realize how fast the prop would push this thing on pavement and went for the ride of my life, no brakes and a pull stick for steering. anyways after the pucker about pinched my hemorrhoids off ,i got it to stop . never again did i try that. this was a plane that flys by parachute and has three wheels with a rotax motor in back pushing a 4 ft three blade prop. I bet it hit over 50 before i new what the heck happened..lol

Why not just mount the propeller on your head, that way you just go where you look Haha

Works best if you mount it straight up on the helmet.

dogman said:

Works best if you mount it straight up on the helmet.

Click to expand...

EVTodd said:

I just noticed this quote too: "you cant get in trouble riding it around on the road in my neighbor so id call it street legal". Too funny.

Click to expand...

LOL....The only reason no one has flagged him down on the "street legal" thing, is out of fear of losing an appendage

Blessings, Snow Crow

this guy aint the first..... take a look at these




http://www.youtube.com/watch?v=7h7AmVPpaEY
http://www.treehugger.com/files/2007/06/the-diy-propeller-trike.php
http://www.youtube.com/watch?v=4sBPsCu-arY
http://www.youtube.com/watch?v=Klh5AyCOvmI&feature=related

its all good till someone loses a finger!!!!!!!!!!!!!!

bob in phx

I just calculated the expected efficiency for a reasonably ideal high-quality system to be about 46-66% with 56% expected as average, not including battery losses. Compared to a direct-drive's efficiency of 70-80% with a peak efficiency achievable in the 80-85% range, it's clear that an RC motor(such as that one used to here) is more efficiently used as a direct-drive system, assuming adequate cooling and a reasonably ideal gearing. But the nearly constant force that'd provide all over the speed range *would* be nice, but it'd be more powerful as a direct-drive.