Electric Bikes - Under $250 brushless Ebike

There are plenty of hub motors out there but I still wanted to see if these low cost, low weight, high quality/high power components could compete with what is out there.

$60 brushless outrunner motor (400W-800W)
$50 speed control (60A 12V-16V)
$18 throttle
$99 beach cruiser (Aluminum frame, steel forks)
$Lithium polymer power! Only 5 ounces per 2AH or 6AH per pound at 12V!!!

Note with Lipolys you can run a motor at 12V and amps above 50A no problem!!!
Chainging together lipolys in series to get voltage over does the amount of amps available and is why packs sound so expensive that way. Keep it at 12V and in paralell and the money problems are solved with hundreds of amps available in power.

Weight for the setup including battery, speed control and motor is just a few pounds!
Adding 2 more horsepower (2 more motors) would only add 1 pound!

The bike pushed me around find without needing power from me.

Note:
This is just a quick test setup and not even meant for a bicycle necessarily.
The motor should be mounted to take strain off the shaft to prevent damage to the motor.

Thanks!
Steve

Oh, I was fully expecting to see pictures. Please do post them. I've been looking around for e-bike set-ups myself, just to help me climb some hills.

What's your range on a full charge? Assuming flat, with absolutely zero pedaling. Top Speed?

Here is photos and video:
http://www.slofly.com/ebike/

Range depends on batteries.
Since this bike is using lithium polymer it can go farther with less weight than any nicd or nimh bike with the same setup.

Decently priced 20AH lipoly packs are not too far off.
Before I purchase or make a production Ebike it needs to go 20mph+, have good low end, be brushless, silent, use lipolys, charge in an hour and not cost a rediculous amount of money.

Going through the gear is mandatory if it is proven even the best hubs or outrunner setups can't beat the efficiency or if hubs don't freewheel without the magnets cogging and slowing you down etc...

Oh yes as expected the drive needs to be supported on both sides.
On the way back from the market the bearing started to go out on the motor from the excessive side force.

The zap brand motor has two motors on each side.
I don't like the friction drive though!

This was only a test on the motor to see what it can do and it performs nice on 12v :)

Hopefully the motor is of interest to you all if not then there are some pleasing things for me to find in Ebikes!

A 5 AH battery will only give about 10 mins running time. A useful running time will require a lot more battery weight which will require stronger wheels. Perhaps a chain drive to the RH side of the rear wheel (or front wheel) would be more efficient and would give better life for the motor bearings.

You could put a 32AH lipoly on there without changing tires or anything.
Weight is around 5 pounds!
I made the 4AH battery from two 2AH batteries just for the test.

This motor is really worth checking out.
For instance on Ebay there is an 8 pound 500w motor.
In contrast this outrunner motor offers more watts and is only 8 ounces!
That is a 16th the weight.

At 10 volts this 8 ounce outrunner has 6480 rpm (it is 640kv)
So it needs reduction or a small shaft if driving friction.

Outrunners may offer more torque, power and efficiency in a smaller package than most the motors used on bikes today. Let me know if there is a reason why they are not being used.

If the hub systems out there drew 50 amps and were 12v they would be 600 watts.
This would be great for using todays lithium packs.

But the hub systems are 36v and 48v and you must series many lithium packs then do paralells of the series to get your mah up.

Lithium packs are typically 3 cell and 12 volts.

So sounds like the hub is the best deal mechanically (because it is a huge outrunner) but the problem is the voltage for lithium packs.

I'm not sure how well the hubs are made- they could have many poles and N50 Neodymium magnets or have ferrite magnets and not be living up to their potential??

I have several motors and stats indicate voltage has little to do with efficiency.
So you can use less voltage at higher amps as long as it is all setup for it.
This may be the case with my outrunner doing so good on 12v and putting out 1/2 horsepower (350watts) on the test bench.

It does not have to be 36V or 48V to get you a horsepower because the paralell lipolys can handle the amps.

What needs to happen is the hubs need to be made 12V and draw more amps to get 600 watts (50 amps)

Since the 12v batteries handle 20 amps at 2AH imagine that 10 of my batteries would give 20AH and handle 200 amps (at only 40 ounces weight!!!)
At 1/4 its draw (50 amps) the pack would not get warm at all!

The zap motor uses two motors on each side.
With two of the outrunner motors it could use a bigger wheel to the tire, go around 40mph and have around 2 horsepower.

My motors are faster RPM- 640 rpm per volt.
To power a pedal crank directly it would need to have a reduction setup. You could get way more than 5:1 with a few inch diameter gear for it to reduce onto.

If I had mechanical skills there would be 4 or 5 of these bikes with each type of drive train possible but I don't so hopefully y'all can help out there.

Here is a link to the video showing the bike being ridden (filmed by me while riding!)

click here for video (http://www.slofly.com/videos/slofly_ebike.wmv)

Hmmm... very interesting!

regarding hub motors ( i have a few of them ) .. the voltage needs to be up there to generate the RPM's needed, no gearing, the rotor is the axle... vs the friction wheel setup you have..

But motors typically use 20 amp and 35 amp controllers instead of 50 amp + ... wich results in smaller A/H batteries needed.. it all works itself out the same.. in terms of watts.

the hub motors are alot more quiet than your setup.. that thing is neat.. but loud.

if you could build a plate to support the roller on both sides with heavy duty bearings, and have the motor hanging from the plate, it would be alot easyer on the motor's bearings.... mount the plate to a spring activated lever.. pedal to a starting roll and then go.. don't use the motor for dead stop usage..

Buzzz,
Thanks for responding!

Oh yes I want two hub motors and a 20AH lipoly pack (just a couple pounds) but I can not afford a hub motor at this time.

I'd love to have a mount with spring as you mention.
Perhaps with the steel friction wheel from the ZAP. Or maybe convert a ZAP.
I've got no mechanical means is anyone up to helping out?
The bike would rip with two of these motors on it- about 35mph with low end power.

Two 1 pound motors giving out up to a total of 2 horsepower is awesome!

Ashame it is irrelevant now with hub motors? :)
Because to make my motors run the bike nicely requires sprockets, chains, gears or friction. Nothing beats the hub- nothing.

Hub motors are an elegant solution but they have some limitations. The hub locks you to a single or 2 speed (second winding in the hub) which means low torque at low speeds with direct drive and a predetermined top speed commensurate with enough torque to get moving.
A geared hub sacrifices top end for sheer grunt on hills and takeoff, a motor driving at the bottom bracket or even just using the rear sprockets would allow use of the bikes gear train so heaps of power for climbing and good assist at high speeds.
I have a few hubs, and really steep hills and off road mountain trails show the short comings of the hubs pretty rapidly. I have seen a few outrunner style motors on ebay with highish wattages and relatively low rpm around 900 rpm which would reduce gearing requirements dramatically.
I have concerns about these motors longevity in prolonged operation ie. an hour or 2 continuously everyday, I have 1 hub with thousands of klm on it an it still runs as new.

A hub and outrunner are the same thing from what I can tell.
Outrunners run forever except for bearings and possible demagnetization over time.

I am suprised to hear they needed a torque and high speed wind.
The whole thing that makes outrunners rule for airplanes is that they have low speed torque and plenty of rpm.
Since a hub has a much higher diameter the torque should be much stronger.
BUT it is a 1:1 ratio
The outrunner I put on the tire has probably a 100:1 ratio.
So my guess is the diameter still isn't much for a hub motor when compared to the torque required. The diameter (wider is lower gear) still isn't low enough even with fat rare earth magnets and mega coils around huge stator teeth.
Still that is suprising but I believe it because millions of $ was put into hub motor research.
With the outrunner (non-hub motors) the video shows it can push the bike slower than I can ride but it would take two of them (2 horsepower) to really help with hills.

It needs a freewheel too and I'm looking at Zap motor setups to try and make a new friction motor mount.
Two of these outrunners on 16v will push the bike over 30mph (maybe 40mph) and have decent low end power.

very interesting thread !

first:
i don´t think that (all) hub-Motors out there are geared 1:1 !!

i have seen a video of one running with open case... (a 1000Watt brushless E-bike-Hub-Motor):

you could see - like on outrunners from my rc-airplanes - the windings at the inner side not rotating (like on all BL-motors),
than around that a ring (with the Magnets) running around the Motor, AND around that the housing with the wheel rotating opposite direction with of course less rpm)

so there was definitly a reduction between the motor itself (hidden in the innerside of the hub-motor) and the hub-motor outside you can see with your eyes..

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for the thing with the Lipos:
i use a lot of LIpos too (Kokam, Xcell, thunderpower, Flightpower, and some more)
and also LiIon (Konion 1100 18650VT, ...)
and FePO4

you made a list of price of your $250 E-bike..
but you forgot to mention the price of the Lipos (i know why ;) )

a 3cell 4000mAh Lipo-Pack of good quality is around 100US$
your Pack with 20.000mAh would be around 500US$
so not realy a cheap thing *lol*

weight would be around 1500g of the 20Ah-Batterie.. (so no problem for a bike)

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how would i do it:
next Post

mounted left


mounted right


with good power and great handling because of weight-balance


so.. i like this idea here (maybe even more than a hub-motor):
http://www.bike-elektro-antrieb.ch/

the wheels keep light, and you can use the gears on your rear-wheel, so
--> high speeds when going onroad
--> low speeds when going up steep hills

here some very good pics:
http://www.bike-elektro-antrieb.ch/Produkt1.htm

i would like to use an Outrunner
on the pics i could see that the gearing with the chain is about 1:4,5 ?!?
would you agree ?

so the paddels need to go with about 80-90U/min
with 1:4,5 ---> so the motor-output should spin 400rpm/min

when i look for Rc-plane-Motors:
for example this Orbit 30-14:
http://www.plettenberg-motoren.com/Datenblaetter/Orbit/Orbit30_14.pdf

peaks of 2500Watt are possible (just to show what the motor is cabable)
and it weights only 305g
(but even if it was 600g it would be unimportant when you think that you and your bike are over 100000g ;) )

this motor would spin - i prefer higher volts over higher amps because of better efficience -
at 27Volt with about 12000rpm - 13000rpm
(i have used Outrunners with only 7000rpm in my heli.. and its running way not that powerfull and efficient like a outrunner with double rpm and higher gear-reduction)

so: to get the 400rpm we would need a 30:1 Gear-Reduktion

hmm - that should be possible to be achieved by a two-stage belt-drive
so: 7:1 first stage with smaller belt and 4:1 at second stage bit bigger, stronger belt

that should be relative quiet as well, i bet ?
to protect everything you can laminate a case from Carbon (would also look cool)
and seal everything as well (to protect from dirt)

when you drive a bike with full suspension, the electric driveline-parts would beguarded by the suspension, wheels would be still as light as normally for good performance and handling offroad

for the batts:
i would not take LIpos..
Lipos are too fraquile, and - when treated wrong way - can burn..

i would go with A123-Systems FePO4 cells, the new technologie..

benefits of the cells:
can handle up to 50C currents
can be charged with 4C (= 15min charging time)
or - if you except a lifetime of the cells of "only" 200-300 cycles - even with 10C (full to 95% within 5min !!!)

the cells have a hard-case like NiMh,
the are absolut safe (will not burn unlike LIpos)

and have a shelf-lifetime of 10 years (lipos only 2-4years)
and a cycle-life in such a bike-application of FAR over 1000cycles (more like 2000-3000cycles)

compared to NiMh (100-200cycles in reality) or Lead-acid (500cycles)
a HUGE benefit !!

you can get that cells cheap when buying DeWalt 36Volt-battery-packs from ebay..
(they are used in power-tools)

3 packs would cost 300Euro
and delivere 36Volt (under load about 27volt) and about 7000mAh
the cells have the same high voltage from start until end of discharge, so unlike NiMh, LiPos or lead-acid, you will not notice any power-loose until its there...

and: a 7000mAh-Pack can easily handle 200A continously and 300A peak..
(that would mean: 10cells, 2,5Volt, 300A --> 7500Watt Peaks *lol* - not needed, just shows that you can not stress this cells to death in a bike like you can with lead-acid !)

weight of such a 36V-7000mAh-Pack: about 2200g

also nice:

batts are in the frame
front AND rear-wheel-drive
40km/h+

oh:
ebikes with good performance have 36V or 48V and suck around 35A with a good, efficient hub-motor..

so 12Volt is a little bit far off for descent performance
(you would not want to have 120-140A in such a bike)

What am I suppose to be looking at again?

the posted ebike is an example of the technology not a finished product to judge distance/power on.
If you examine the weight and power of it then it is easy to see it can out do any lead acid brushed configuration when expanded.

That is actually a 20+ volt motor on the ebike and only running at 12v
The drive train is only to show you it has the power to push- it is not an example of good drive train for propulsion.
It just showed you the technology. It is your job to apply it to a bike.

In under 2-3 pounds you can have more amps and volts than a 20+ pound battery lead acid.
With the value attached to bikes and the money that goes into making them hold 50 pounds of batteries you can put that $ into light weight smaller, stronger lipolys and leave your bike looking cool.

In 8oz we have 500w+ of power in a motor.
The old fashioned brushed motors don't cut it.
Forget about brushed motors.

Just think about what 2-3 horsepower outrunner setup to a dynamic planetary gear can do.
Hard accelleration, variable torque which is programmable through the planetary gear for optimum torque and rpm at any speed.

So take it to the next step by understanding it before closing it out with thinking like- there is only 3 batteries on there so you can only go so far... if you think that then do not post because you are not engineering but waiting for a perfect answer. We're working on the answer because we have all the pieces to put it together.

I'm not happy with weak 50+ pound bikes using 70's technology when we have 07' tech right here unused.

Hey, so Durace600 really can "dial it up to 400 watts" on these bikes. And he can be sitting down when he gives "the look."

We've been waiting for a simple conversion like this to get our feet wet in E-cycling ... where did you get your friction roller??? Been building adult chopperbicycles for years ...now time to go E-power...:D

Hello-- Where do you buy the 1 horse power motor and other componenets for the light-weight bike? --John.

Thanks for the informative thread. You may also want to go to the visforvoltage.net forums. They have a subforum called "bikes and pedelecs". A lot of good practitioners there with what you're trying to do. Good luck and keep us updated.

moved there maybe there will be more posts
http://visforvoltage.net/forum-topic/bicycles-and-pedelecs/861-links-drivetrains-ebikes

If anyone has links on the drivetrain in post 16 please post them here or at the link above.

Thanks!!

I'm moving this to the new Electric Bikes subforum.

--J, a Forum Mod

This is just a quick test setup and not even meant for a bicycle necessarily.
The motor should be mounted to take strain off the shaft to prevent damage to the motor.

Thanks!
Steve

Hmmm.... friction drive. I've had trouble with friction drives in the past. Most notably my Go-Ped. Friction drives chew through tires real fast and they have lots of trouble when wet.

I built a similar system to that a while ago. The issue I had is that the motor driving the pedals would whack me in the leg if I took my leg off the pedal for some reason.

Personally I think a hybrid crank and hub-wheel would be the best. Let me explain:

The Bion-x system uses a strain guage to mesure the amount of force applied. It can also freewheel. So imagine this: You take off the crank on the right side of your bike and replace it with a hub motor and bolt-on some gears to the case. You run a freewheel shaft through the middle and you attach the pedals at either end of that shaft. Then you simply run the chain over the hub-now-turned-crank motor to the rear derailleur and you're done.

When you pedal you're pedaling the "crank motor" instead of the hub motor. When you press the thumb throttle it turns the crank motor but not the pedals (freewheel remember?). And when you pedal hard, the motor can detect the amount torque on the strain guage and provide the proper assist.

The advantage is that you can use the bike's own gearing as a mechanical advantage for various terrain. And since you can switch to a higher gear when going fast, the "crank motor" won't be spinning quite as fast. Slower RPM = more battery life.

The only thing I haven't figured out yet is how to run the wiring to the "crank motor".

$Lithium polymer power! Only 5 ounces per 2AH or 6AH per pound at 12V!!!

Note with Lipolys you can run a motor at 12V and amps above 50A no problem!!!
Chainging together lipolys in series to get voltage over does the amount of amps available and is why packs sound so expensive that way. Keep it at 12V and in paralell and the money problems are solved with hundreds of amps available in power.

Hi,

technically speaking, I doubt it that you did run your 12 V lipo pack as it was shown on the vid. within recommended current limits of the pack... Most lipo packs will not support more then 2C current, so if you have 4 AH lipo then you should have some current limitation circuitry which will limit motor current to 8 A... the motor you used can draw 50 A so that would mean you would need lots (= 12) of lipo-packs in parallel to have enough reserve for steep hills.

cu
Zardo

I like the ingenuity and inventiveness shown here, but prefer the simplicity of a hub motor. Snap a bottom bracket, break either chain, etc, with this setup and you're stranded. With a hub motor on the front wheel you have 2 completely independant powertrains, either of which can get you home.

Hi!!! first time on this forum I like to learn more I appreciate any help! I have a few questions... please lead me to the answer if it has been asked before.

when using a motor driving the pedals set up as pictured above,

Does the rider have the option of using it only to assist pedaling or the motor has to be running at all times while riding?, Can it be turn on and off as desire or needed?
Thanks

Now , for us old guys who don't go that far or pedal in the rain.... Friction drive would be a cheap /easy conversion...just a spring /bracket thing with a manual lift ... how what would be the best (and easiest) way to support the motor shaft , no gears or belts please...how about a simple box frame and a bearing on each end for the friction drive shaft... Pretty simple , and not too $$$ like some of these conversions ...
I just need to go about total 12 miles to our closest store and back , on flat roads in nice weather only ...speed ...12-15mph would be nice ...Geezer power, not Gasoline ...

Look up the EVwarrior, I'm sure you could figure out how to make something workable along it's lines if you're crafty. (Or just get a used EV warrior, should be doable for under 250$)

But I'd rather MAKE something for powering my own chopperbike creations...CRUISER...

Cool! But as was mentioned once or twice in this thread...how durable is this? maybe I am old fashioned but I have always thought that there was a bit of a direct relationship between weight and durability. If someone has a setup like this...I wish you would take it out on the road for 10 or 12 hours with spare sets of batteries and run them continually to see what happens.

Well made /setup is different from some hack job...and both can be just as expensive...or not...
Pen , if only I could ...???hahahahaha I wish too ...

to Zardo:


Hi,

technically speaking, I doubt it that you did run your 12 V lipo pack as it was shown on the vid. within recommended current limits of the pack... Most lipo packs will not support more then 2C current, so if you have 4 AH lipo then you should have some current limitation circuitry which will limit motor current to 8 A... the motor you used can draw 50 A so that would mean you would need lots (= 12) of lipo-packs in parallel to have enough reserve for steep hills.

cu
Zardo

you are speaking about batts from 6-7 years ago..
we meanwhile use for 5 years batts that can handle 5-8C contiouse
we use since 3-4years batts, that can handle 10-12C continouse
we use since 2-3years batts, that are rated for 20C continouse (and in reality are able to handle 15-18C without cooling)
and since this years the first 30C-continouse-batts (again: 20C continouse without cooling) are on the market and used..

for your 4000mAh-example:
http://www.elektromodellflug.de/akku-test/kokam-30c.htm
look at the first two diagramms, measured from Gerd Giese, a unindependent batt-tester in the rc-community

so you see: the battery can deliver 25C continously, reaching 66°C without cooling
lets stay under 60°C, still that are 20C or 80A current..

a 3s Lipo would give 10,35Volt average current at 80A ---> so around 830Watt power
not bad for a little tiny 320g battery !

of course you can not expect several 100 cycles at such load..

so: let stay at 10C... you will see many 100 cycles
and still: that are 40A current

for cycle-test with high current look here (test in English language):
http://www.slowflyer.ch/downloads/tn07004.pdf

to sum up the test:
batt was charged with 2C (so 30-45min for full charging)
discharged with peaks up to 120A (30C), laverage discharge was 9C (=36A)

after 360cycles there were 92% left of original capacity when pack was new,
voltagelevel at 12C continouse discharge 99% of original voltage when pack was new

so 2C-Lipos you mentioned --> this kind of low-power-lipos are used for laptops, handies, and unfortunatly on many e-bikes as well..

Hey Outrunner,

I am VERY impressed about what you have done. This has sparked other innovative ideas for me. Can you please list where you got each of your parts, so that I can buy and test/improve this idea.

Thanks!
Tony

to Zardo:

you are speaking about batts from 6-7 years ago..
we meanwhile use for 5 years batts that can handle 5-8C contiouse
we use since 3-4years batts, that can handle 10-12C continouse
we use since 2-3years batts, that are rated for 20C continouse (and in reality are able to handle 15-18C without cooling)
and since this years the first 30C-continouse-batts (again: 20C continouse without cooling) are on the market and used..

for your 4000mAh-example:
http://www.elektromodellflug.de/akku-test/kokam-30c.htm
look at the first two diagramms, measured from Gerd Giese, a unindependent batt-tester in the rc-community

so you see: the battery can deliver 25C continously, reaching 66°C without cooling
lets stay under 60°C, still that are 20C or 80A current..

a 3s Lipo would give 10,35Volt average current at 80A ---> so around 830Watt power
not bad for a little tiny 320g battery !

of course you can not expect several 100 cycles at such load..

so: let stay at 10C... you will see many 100 cycles
and still: that are 40A current

for cycle-test with high current look here (test in English language):
http://www.slowflyer.ch/downloads/tn07004.pdf

to sum up the test:
batt was charged with 2C (so 30-45min for full charging)
discharged with peaks up to 120A (30C), laverage discharge was 9C (=36A)

after 360cycles there were 92% left of original capacity when pack was new,
voltagelevel at 12C continouse discharge 99% of original voltage when pack was new

so 2C-Lipos you mentioned --> this kind of low-power-lipos are used for laptops, handies, and unfortunatly on many e-bikes as well.. Kokam packs have been around for many years as the best RC packs and they keep improving unlike many other lipo cell manufactures.With a 50 lb ebike including the motor and 7 lb battery you can expect a 25 mile range at 20 mph even without pedaling if your motor is above 90 % efficient. For each additional pack add on another 25 miles in range and 7 more pounds.Or 3.6 miles per pound of Kokam lithium polymer batteries discharged to 80% of the packs rating for long life.
For $50. you could get a NEW 300 watt, 600 watt peak ZAP motor and roller on it.
http://tinyurl.com/2gzral

Does anyone have a power curve for this motor? It looks great, but I, too, am a little old fashioned and often think that light things will not be so durable. Still, If I could find one in China I would be willing to slap it on my bike and give it a go.

It should be even easier to rig up a NIMH pack that would easily power the bike ...New Nimh have developed , and are Cheaper and easier to charge than the lipos ...Like the idea of front wheel drive of any sort , no modifying the chain drive business... Simple , Logical !!!!

I have a new super easy electric bike that can go about 25mph flat and it combines with you pedaling, free wheel. It is lighter than any other ebike kit out.

Please check it out and order one and I promise 40mph+ in less than one month.

Part 1:
http://www.youtube.com/watch?v=xmv7EOP0NF0

Part 2:
http://www.youtube.com/watch?v=ElDojoIoMq4&watch_response

A video will be made on flat ground to test and show range. It should be about 10mi per 5ah

Please let me know some various ranges per battery size of bikes out there.
This works out much more efficient than expected and will do much better with a larger less pitch prop and larger motor.

This thing is an accident waiting to happen without a cage around the prop. Yours only chewed up a table, but my friend lost a finger to to his RC airplane.

Seriously.

It is the most dangerous vehicle ever without a cage.
Too bad there is no cage available at the store for it, or someone to help gear it onto the chain which is the goal.
Any ideas how to cage it or gear it?

I am not able to build a cage or gear system at this time and need your help.

Geared will be more efficient than direct drive and have a wider power range.
It will also have a high top speed in high gear and have very much torque in low gear.

This dangerous thing exists because I was unable after a long time to get help even identifying parts online.
This is reluctantly built because I am drooling to use the motor geared but not in a position to install it.
Posts on danger for safety sake are appreciated of course.

This project is to show how light and fun these type of motors and batteries are and attract help to get it onto bikes cheaply. If there is an Ebike kit out there with over 1000w, brushless, under $500 and not direct drive let me know so I do not have to have this idea on my back any more. :)

The video should excite you about the light weight battery technology and high power in a small light package motor technologies. Does it? Its over 2 years I've been posting and asking for help with brushless and lithium batteries.
Typical pattern is resistance then the next wave is replies saying there already is bikes with lithium.
That is the case now of course but I still can not find a geared one at an affordable cost (under $500)

We can bump it up to over 6000watts and have a shoe box size of batteries about half the weight of lead acid with double the power and triple the ability to dump power for the longest range lightest bike you can imagine.

This type of motor and battery combo gives a high power very long range bike which you can carry up stairs easily.
It only takes one hour to charge the packs regardless of their size. Charging at destination is quick and not required if you simply double your supply of batteries (100 mile range reasonable for 2 shoe box size of batteries)

I've been posting and trying to get this done so long that lithium ion has come into usage finally on bikes and there is probably something out. The hub motor is great but I would like something to push me over grass or a dirt clod field in low gear too. There is nothing I can find that can do this under $500 or so.

Post your interest level in having a 1000w to 3000w bike that can push you up steep hills or go over 35mph on flat with a 15 to 30 mile range at under $500.00

Mention your ability and skill to help put it together and we will have an instant build group.

Too bad there is no cage available at the store for it, or someone to help gear it onto the chain which is the goal.
Any ideas how to cage it or gear it?

attach one of these to your rear wheel:
http://www.google.com/products?q=%22%2325%22+sprocket+80+tooth

attach one of these to your motor:
http://www.google.com/products?q=%22%2325%22+sprocket+%229+tooth

buy a #25 chain (a go kart type chain).

pick a motor that's around "480kv" and get 3-in-series LiFePO4 battery (about 9.5 volts)

... or about 360kv and 12 volt lifepo4 for the same speed.

Thanks it is elegant for 1:1 ratio thanks!

The front wheel hub motor is the perfect solution just skip the steep hills and dirt fields unless you pedal.
Relatively flat to work? Just switch to lipoly on a hub motor and go double the distance with half the battery weight.

The weakness of the front wheel hub motor is it can not supply low speed torque and high speed riding in one package.
To bring us a dynamic speed and torque range, more fun and lower cost we need chain assist.
With chain assist we still get our gears and the motor is able to help with much force at slow speeds or much speed when traveling fast.
From the first video where the motor is direct drive one person made a nice chain assist.

If we can have a machinist make an adapter for the motor we are able to have a bikeforum open gear project.

I hope for something easier however.
The project calls for gearing through chain.
The brushless motor rpm is reduced to turn small sprocket which powers bike chain with high torque.
First version needs no freewheeling it is a flat ground power test. Legs in the air with pedals spinning around.

How about a piece of wood with the motor mounted on it facing up.
The sprockets are bolted on the wood and the reduced sprocket spins off the side.
The board is simply mounted on the frame and presses down on the chain either behind the main sprocket or in the middle if it has a guide to keep the teeth in the chain under torque.
Does that sound feasible?

Thanks it is elegant for 1:1 ratio thanks!

80tooth/9tooth is about a 9:1 ratio, not 1:1

:)

Oh, but my explanation would run the motor through an unchangeable gear ratio rather than multi-speed, it's true.

It is great for high torque I meant to say consistent ratio.

Well after nobody helps with the geared one or just helps themselves I may give it a go!
Any ideas how to adapt a 6mm or 9mm shaft to one of those bike sprockets with a larger center?

:)
It is great for high torque I meant to say consistent ratio.

Well after nobody helps with the geared one or just helps themselves I may give it a go!
Any ideas how to adapt a 6mm or 9mm shaft to one of those bike sprockets with a larger center?

You probably know this, but a Crystallite 5303 with 84volts will have tremendous torque and also travels around 65km/hr.

That's a hub motor. I have mine in the front and it's awesome.

You started a great thread and many good ideas on it. Thanks. :thumb:

The motor is 24lb? Darn that is heavy.
My 1000w motor is less than one pound!

See my point about outrunner motors and lithium polymers not being utilized anywhere but the RC airplane industry.

I had the same issues with the RC airplane industry and their last motors and batteries.
Now the whole industry is switched over.

I'm suprised the first youtube video showed how many people do not understand amps, watts, volts, torque, kv, ac, dc to the point of being totally confused.

I hope someone who knows the lingo people like to hear can take off with this!

Point is the stuff out there is too heavy or too expensive and we have $200 6500w motors that weigh 6-7 pounds or so and the batteries to make it go.

One of you has over $50k in your account and owes it to the world to put something nice together :)

Thanks!!
By the way I've retired from all this innovation stuff after 20 years of doing it non-stop.
I do not find this rewarding and spent thousands researching ebikes.

The entire Bike kit will go on sale on Ebay tomorrow I'm hoping!!

Thanks again!