Is the future Electric?

IH8Rice · Dec 16, 2009

cool idea.

how large is the LiPo battery pack and does it get hot when being used?

SuspectDevice · Dec 16, 2009

500 watts just isn't enough. At all.

Matt 891 · Dec 16, 2009

Mountain biking is demonized enough in the states as is.

having a motor would only fuel the fire for limiting access.

SWEET idea and execution though! props :thumbsup:

Jim Mac · Dec 16, 2009

Anyone see this article in yesterday's NY Times in the Science section:

http://www.nytimes.com/2009/12/15/science/earth/15bike.html?_r=1&em

"The new wheel uses a kinetic energy recovery system, the same technology used by hybrid cars, like the Toyota Prius, to harvest otherwise wasted energy when a cyclist brakes or speeds down a hill. With that energy, it charges up a battery inside the wheels hub."

johnbryanpeters · Dec 16, 2009

Jim Mac said:
Anyone see this article in yesterday's NY Times in the Science section:

http://www.nytimes.com/2009/12/15/science/earth/15bike.html?_r=1&em

"The new wheel uses a kinetic energy recovery system, the same technology used by hybrid cars, like the Toyota Prius, to harvest otherwise wasted energy when a cyclist brakes or speeds down a hill. With that energy, it charges up a battery inside the wheels hub."

Yes. It looked like a masterpiece of unsprung weight.

IH8Rice · Dec 16, 2009

Jim Mac said:
Anyone see this article in yesterday's NY Times in the Science section:

http://www.nytimes.com/2009/12/15/science/earth/15bike.html?_r=1&em

"The new wheel uses a kinetic energy recovery system, the same technology used by hybrid cars, like the Toyota Prius, to harvest otherwise wasted energy when a cyclist brakes or speeds down a hill. With that energy, it charges up a battery inside the wheels hub."

theres a video too
http://www.engadget.com/2009/12/16/mits-copenhagen-wheel-turns-your-bike-into-a-hybrid-personal-t/
http://www.youtube.com/watch?v=<object width="560" height="340"><param name="movie" value="http://www.youtube.com/v/S7y3qIQu3Gc&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/S7y3qIQu3Gc&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="560" height="340"></embed></object>

vtminuteman · Dec 16, 2009

A related design idea that would be cool is a small spring drive system. When brake you wind up a spring. Then a button on the bars releases the spring drive exiting a turn and you accelerate out faster. Not sure how light the system could be made but I think the ability to rocket out of turns would be huge, and fun. If you ask me the above system should be beefed up and sold as a electric powered light dirt bike. It would be slow going up hills but way fun going down and on flats.

kidwoo · Dec 16, 2009

ZUMBI said:
motor 500W 48V

The bike can climb up to 45 degree slopes.

Um

No

kOlsen · Dec 16, 2009

No thanks

I like to pedal

norbar · Dec 16, 2009

kOlsen said:
No thanks

I like to pedal

You can pedal your downhill bike up steep mountains few times a day? I'm impressed.
Seriously though if it works it's a good idea for people with no lifts/possible shuttles close by. If it will work, why hate it?

kOlsen · Dec 16, 2009

norbar said:
You can pedal your downhill bike up steep mountains few times a day? I'm impressed.
Seriously though if it works it's a good idea for people with no lifts/possible shuttles close by. If it will work, why hate it?

I don't hate it. I just don't want/need it.

amazinglarry104 · Dec 16, 2009

thats pretty sweet
Could be usefull for certain people / situations

As an alternative you could attatch a grappling hook connected to a winch that you shoot to the top of the mtn and it pulls you up

SuspectDevice · Dec 16, 2009

Jim Mac said:
Anyone see this article in yesterday's NY Times in the Science section:

http://www.nytimes.com/2009/12/15/science/earth/15bike.html?_r=1&em

"The new wheel uses a kinetic energy recovery system, the same technology used by hybrid cars, like the Toyota Prius, to harvest otherwise wasted energy when a cyclist brakes or speeds down a hill. With that energy, it charges up a battery inside the wheel’s hub."

there is such an assine amount of increased drag with regen- and there is nowhere near enough regen to make up for it.

Any electric bike can be programmed for regenerative braking- It's useless, and is pure marketing hype. Any electric bike with less than 1200 watts of power assist is completely useless for a real bike rider.
A 500w motor- that's the peak power output- to get hours of runtime is going to mean a delicate hand on the throttle and an average wattage of around 225w or so- 22kg at 225 watts- well um... assuming a moderate effort by the rider (who is already in a suboptimal cycling position) is ~400 watts up hill total? On a ~22 kg bike? Assuming 106kg for the bike and rider combo at 400 watts including rider input you have 3.7 w/kg. Without rider input you have ~2 w/kg which is going to get you up a hill ridiculously slowly- Pushing is going to be faster.
My math here sucks- but this thing just isn't practical without more power.

I've designed and built quite a few electric assist bikes and trikes. They are great for sexagenarians and as adaptive technology- but even for commuting use they are complete impractical for anything more than a few miles- and even then they must be operated at amperages that complete eliminate the benefit of the power-assist, and like a Toyota Prius, less efficient than the conventional powertrain they replace due to added mass. The need for front-freewheel cranks or an IPS is also a major bummer.

It must be a superfun development project, but the need to run the fuel cells on your back? That is a big drawback- most people don't even want water on their backs for aggressive riding, let alone a fuel cell on their back that can explode at any time.
Electricity+ bikes is only useful for shifting or lights atmo.

jon-boy · Dec 16, 2009

amazinglarry104 said:
thats pretty sweet
Could be usefull for certain people / situations

Wow, tough crowd... though I quoted the above as it's a good point. For us who like to ride bikes it's likely not going to be 'that' popular. Niche for sure.

However if you are trying to encourage more people to ride bikes to commute to work in cities... then this might be the encouragement that they need.

norbar · Dec 16, 2009

jon-boy said:
Wow, tough crowd... though I quoted the above as it's a good point. For us who like to ride bikes it's likely not going to be 'that' popular. Niche for sure.

However if you are trying to encourage more people to ride bikes to commute to work in cities... then this might be the encouragement that they need.

Seriously you think they key in designing this bike was commuting to work? With fox 40's? I don't know in which cities you live but mine has pavements and roads not roots and rockgardens

Toshi · Dec 16, 2009

kidwoo said:
Um

No

it's running through the geared drivetrain so it might be possible at a crawl.

SuspectDevice said:
Any electric bike with less than 1200 watts of power assist is completely useless for a real bike rider.
A 500w motor- that's the peak power output- to get hours of runtime is going to mean a delicate hand on the throttle and an average wattage of around 225w or so- 22kg at 225 watts- well um... assuming a moderate effort by the rider (who is already in a suboptimal cycling position) is ~400 watts up hill total? On a ~22 kg bike? Assuming 106kg for the bike and rider combo at 400 watts including rider input you have 3.7 w/kg. Without rider input you have ~2 w/kg which is going to get you up a hill ridiculously slowly- Pushing is going to be faster.
My math here sucks- but this thing just isn't practical without more power.

It must be a superfun development project, but the need to run the fuel cells on your back? That is a big drawback- most people don't even want water on their backs for aggressive riding, let alone a fuel cell on their back that can explode at any time.
Electricity+ bikes is only useful for shifting or lights atmo.

1) LiPo != fuel cell
2) your assertion that e-bikes under 1200W are useless is patently false. many commuters in tokyo and new york would disagree, not to mention yours truly with the 700W creation that replaced my car last year.

SuspectDevice · Dec 16, 2009

Toshi- You've got to admit that a 500w peak power electric DH bike would totally suck climbing, would you not?

Sandwich · Dec 16, 2009

ahhhh I'd love to commute on that thing.

It would be great for "shallow" mountains too, or even a trail ride in the backwoods. I dig it. I take it you wear the backpack on the way up, unplug the battery, then ride down? Could be fun for boost in certain sections too. psuedo moto.

What's the estimated cost, or what would it cost to actually do one? What's the charge time?

norbar · Dec 16, 2009

Sandwich said:
ahhhh I'd love to commute on that thing.

It would be great for "shallow" mountains too, or even a trail ride in the backwoods. I dig it. I take it you wear the backpack on the way up, unplug the battery, then ride down? Could be fun for boost in certain sections too. psuedo moto.

What's the estimated cost, or what would it cost to actually do one? What's the charge time?

Dirtmag site said 2100 pounds If I'm not wrong.

About the battery thing - that's the way Paweł explained it to me in Schladming.

kidwoo · Dec 16, 2009

Toshi said:
it's running through the geared drivetrain so it might be possible at a crawl.

Go get an angle finder and find yourself a 45 degree slope outside.

Now envision you on a bike going up it, on a bike, regardless of the power output without looping out.

45 degrees makes most people shake when SKIING. I don't think our zumbi friend really knows what a 45 degree slope looks like out in nature.

2) your assertion that e-bikes under 1200W are useless is patently false. many commuters in tokyo and new york would disagree,

Those are pretty hilly places for sure.....

trust4130 · Dec 16, 2009

SuspectDevice said:
Toshi- You've got to admit that a 500w peak power electric DH bike would totally suck climbing, would you not?

Especially when you could have 4 or 5 thousand watts...

http://www.recumbents.com/WISIL/shumaker/default.htm

Toshi · Dec 16, 2009

trust4130 said:
Especially when you could have 4 or 5 thousand watts...

http://www.recumbents.com/WISIL/shumaker/default.htm

matt's bike can go 45 mph. it's not the typical case by any means.

500W with a 2.2 kg weight penalty > 0 W with a 0 kg weight penalty in my book. whether it actually equates to 45 degrees, or whether the rider can even stay on the bike while climbing something like that is another issue.

jon-boy · Dec 16, 2009

norbar said:
Seriously you think they key in designing this bike was commuting to work? With fox 40's? I don't know in which cities you live but mine has pavements and roads not roots and rockgardens

I live in Vancouver. Nuff said.

I meant take the technology and put it on commuter bikes... smart arse. :rofl:

trust4130 · Dec 16, 2009

Toshi said:
matt's bike can go 45 mph. it's not the typical case by any means.

Completely agree. This thread just seemed like a good opportunity to post a link up to that custom electric powered beast! It's a work of art in my view, regardless of bicycle type.

basikbiker · Dec 16, 2009

45 degree slope is = a black diamond run at a ski resort, thats super steep if your just gonna put put up sumthin like that, moar power

numerik · Dec 17, 2009

Isn't this then...a moped? This looks better idea to me...at least more fun

frango · Dec 17, 2009

I've never liked the way f-44 looked. With all the stuff attached it looks even worse. It's hidous.
Electric bikes are not the future. Hybrid probably are. But not at this price point and this usage time/milage.
Look at average city hybrid bike. It weighs about 30kg.
I didn't do my best to build 15,6kg bike just to put additional 5kg engine and fuel cell.
Pointless IMO.

Toshi · Dec 17, 2009

frango said:
I've never liked the way f-44 looked. With all the stuff attached it looks even worse. It's hidous.
Electric bikes are not the future. Hybrid probably are. But not at this price point and this usage time/milage.
Look at average city hybrid bike. It weighs about 30kg.
I didn't do my best to build 15,6kg bike just to put additional 5kg engine and fuel cell.
Pointless IMO.

"Electric bikes are not the future. Hybrid probably are"

what does the above mean? a 500W motor isn't going to propel you faster than 15-20ish mph on flat ground on its own power so you're going to be pedaling, too. that's a "hybrid" for ya

frango · Dec 17, 2009

Hybrid is riding with electric assistance. Not on electric motor, only.
I don't know whether 500W is enough or not.
I know that hybrid bikes are good for the city, only. Riding in terrain drastically reduces range.

essenmeinstuff · Dec 17, 2009

Few points:

- 500W is a decent amount, the average human can maybe do about 200W continuous.
- 500W will climb at 45deg (regardless if such a slope exists), its just a question of how quickly.
- To get 4hrs continuous run time at full power, 2kWhr of output, /0.7 for drive/motor efficiency = 2.8kWhr output from the battery, output efficiency depends on current draw, likely you would need 3-4kWhr battery to do this. Given average power density of Lithium batteries of about 0.5kWhr/kg, you're looking at 6-8kg battery on your back.
- Crashing with that size lithium bomb strapped to your back would not be fun.
- The cost of such a battery would be quite high.
- That 4hrs is probably not at full power, but you would still need a decent battery, and that would still pose a fire risk if it got damaged in a crash.

Basically an e-dirt/DH bike is definitely cool, and doable.

My approach would be a brushless motor from the RC world, peak output about 7hp, run from a 48V lipo. Battery would still cost you a couple grand to get even a couple hrs of fun.

kidwoo · Dec 17, 2009

ZUMBI said:
thanks for all the comments. The 45 degree angle is based on going up a black diamond ski slope. The motor has enough power when You use the lightest gear and pedal and wants to go up but the bike starts to roll over. Anyway we easly rode it up the slope in Schladming where the DH course ends.

You've got to have some videos of this thing in action right?

mklie · Dec 17, 2009

http://www.pointlessbutcool.com/gadgets/revo_power_wheel

IH8Rice · Dec 17, 2009

essenmeinstuff said:
Few points:

- 500W is a decent amount, the average human can maybe do about 200W continuous.
- 500W will climb at 45deg (regardless if such a slope exists), its just a question of how quickly.
- To get 4hrs continuous run time at full power, 2kWhr of output, /0.7 for drive/motor efficiency = 2.8kWhr output from the battery, output efficiency depends on current draw, likely you would need 3-4kWhr battery to do this. Given average power density of Lithium batteries of about 0.5kWhr/kg, you're looking at 6-8kg battery on your back.
- Crashing with that size lithium bomb strapped to your back would not be fun.
- The cost of such a battery would be quite high.
- That 4hrs is probably not at full power, but you would still need a decent battery, and that would still pose a fire risk if it got damaged in a crash.

Basically an e-dirt/DH bike is definitely cool, and doable.

My approach would be a brushless motor from the RC world, peak output about 7hp, run from a 48V lipo. Battery would still cost you a couple grand to get even a couple hrs of fun.

best post yet.
i too would be afraid of damaging the LiPo batteries of that size....or if the motor controller suddenly goes bad b/w your legs.

i think the bike is cool though
am i looking at it right, or does the motor constantly turn the cranks when power is applied?

Sandwich · Dec 17, 2009

IH8Rice said:
best post yet.
i too would be afraid of damaging the LiPo batteries of that size....or if the motor controller suddenly goes bad b/w your legs.

i think the bike is cool though
am i looking at it right, or does the motor constantly turn the cranks when power is applied?

I thought I read there was a freewheel on the crank, so they should turn when the motor is running.

The weight of the batteries is a good point, but I'm sure they'll provide a reasonable amount of security for actual riding use. Think of it this way- every time you're on a motorcycle, you've got a gallon of highly explosive juice between your legs, and it's located inches above an extremely hot, electrically powered device. A small amount of fireproofing and crash resistance shouldn't add too much to the weight of the pack, but a cool option could be attaching the battery to the frame.

essenmeinstuff · Dec 17, 2009

Sandwich said:
I thought I read there was a freewheel on the crank, so they should turn when the motor is running.

The weight of the batteries is a good point, but I'm sure they'll provide a reasonable amount of security for actual riding use. Think of it this way- every time you're on a motorcycle, you've got a gallon of highly explosive juice between your legs, and it's located inches above an extremely hot, electrically powered device. A small amount of fireproofing and crash resistance shouldn't add too much to the weight of the pack, but a cool option could be attaching the battery to the frame.

The problem with the batteries is, even just a small dent or crushing them can cause internal damage, and then you have self ignition.

I used to ride dirt bikes, with spare gas can on the back, crashed a couple times that cause a leak, and once total loss of the spare can, dangerous yes, but it didn't catch fire or self ignite as soon as teh tank was dented...

Take an old cell phone battery and crush it or stab it with a stick or something, then think about having that times 1000 happen with something thats attached to your back.

I like e bikes and I like playing with fire etc but I'm very wary of li ion batteries... even just stupid things like over discharge, or getting a little to warm, or unbalanced cells can cause catastrophic failure.

IH8Rice · Dec 17, 2009

essenmeinstuff said:
I like e bikes and I like playing with fire etc but I'm very wary of li ion batteries... even just stupid things like over discharge, or getting a little to warm, or unbalanced cells can cause catastrophic failure.

Li Ion batteries a lot safer than LiPo batteries...which they said they are using for this bike.

i would feel safer with gas on my bike too than i would a LiPo battery.

Toshi · Dec 17, 2009

IH8Rice said:
Li Ion batteries a lot safer than LiPo batteries...which they said they are using for this bike.

i would feel safer with gas on my bike too than i would a LiPo battery.

refer to post #1. look for "lithium polymer." QED.

IH8Rice · Dec 17, 2009

Toshi said:
refer to post #1. look for "lithium polymer." QED.

wtf are you talking about? i know it says LiPO
it you refer to post #2 you will see that BTW QED STFU

Is the future Electric?

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