What makes a fastest & lightest weight electric bike on earth?
All, I am trying to built a fastest & lightest bike to go to work in San Francisco. The distance is about 10 US miles each way. My current electric bike weight 110lbs with 6 12v 12ah batteries on a 180w-250w motor & the maxium speed is only 12-15mph. Please advice. Thanks!
Without going into specifics what makes any EV fast is a powerful motor. What makes a motor produce a lot of power in a small size is high voltage. What makes an EV light is cutting back on battery capacity, or using a battery chemistry with higher specific energy.
Some of the fastest electric bikes now are probably running 72v with hub motors and lithium chemistries. Someone put an etek motor on a bicycle, but I think that is overkill!
Deafscooter is Here...
ASK Craig Uyeda Deafscooter
For lightness I'd suggest NIMH or Li-ION batteries. If you go the Li-ION route, choose Li-FE for safety.
- David Herron, http://davidherron.com/
Why not get rid of the batteries, recalling some cartoon where they used exentsion cords.
Then since you want to go fast weight and wind resistance become important factors.
So a recumbant, with a airo dynamic fairing, high presure tires.
That was the low buget model,
If you dont want the, long extension cord,
If you can find some super condutors, and super magnets, and a chemical reaction that can,
produce electric energy, at very high rates.
More conventional method a high speed hydrogen powered steam turbine, running a dc generator, feed into a homopolar motor driving the wheel.
Probably you would have a hard time finding a tire the can withstand the speed.
So perhaps the real probem is not the electic motor, but the tires..
Maybe this design would fit your bill:
Your problem is your weak motor....The power rating is pathetic. If you want speed, you'll have to get a motor with more power. Law here in Ontario limits me to 500W and 32kph on flat ground with motor power only. So I have a 500W motor on a 20" front wheel and I do 36kph on flat ground, cruise comfortably with minimal pedalling at 38-39kph. And my kit is on an all steel framed pig of a heavy bike.
Put a Crystalyte Phoenix racer hub on a 20" wheel (smaller wheel is best for getting the most out of your hub motor, don't buy into the 26" hype), and with the 3640 setup (40A controller) at 36V, you'll have all the speed you could need on a bicycle....you don't need 72v systems, etc.....you will kill yourself on a BICYCLE doing 50MPH...period....they're not meant for those speeds....they have nowhere near enough brakes for those speeds, bicycle helmets can't protect your head at those speeds, and if you are using normal bicycle tires and don't change to specialized high speed tires, well good luck to you sir. Even California limits their speed to 30MPH....It just is not safe..... and people are using Lipo's to try to keep down weight with these crazy high voltage systems, and alot of these Lipo packs can't handle the amperage, and others still, some blow up when overcharged....awesome.
Plus, if you want to break the law in regards to speed and use it everyday on the roads to work, etc. you are asking for it if you're flying down the road at speeds well past what is considered a legal bicycle. You get caught by cops flying on your bike...it isn't a speeding ticket...it's, "I don't care about your pedals, mopeds have pedals too...you were doing 40mph...that doesn't mean you were speeding on a bicycle, it means you are operating a motorized vehicle...where's your limited speed motorcycle, or if you're fast enough, full motorcycle license, license plate, sticker, insurance? Oh, you don't have any of that stuff? Well, here are your enormous fines for essentially driving a car with no driver's license, vehicle registration, or insurance."
Good luck to you if you want to repeatedly destroy the law. That way, the governments will stop trying to legislate this headache and just call them motort vehicles and motorcycles again like they used to not too long ago.
Run 36V, run a 500-750W motor (if your area allows 750W, mine doesn't) and you'll have more than enough power to do 20+MPH. If 30MPH is allowed, knock yourself out...of course you are now pretty much at the safe limit for a bike with bicycle brakes and a fluorescent girly styrofoam and cheap plastic helmet.
Giant Stiletto Bike
500W Golden Motors 20" front wheel kit
Flat ground speed: 36kph
Top speed: 44.8kph
Before doing anything else, you could take three batteries off and see if you can charge at work. If that doesn't help enough than feel the motor to see how hot it is getting. If only warm than you might be able to overvoltage it just fine by running it at 48v. I think we missed the point of the thread.
I agree with friggerand about power, you need to select the right medium for the power and speed you want with safety in mind. And the bigger and faster you get, the more you are crossing into the registered vehicle domain. My motorcycle might be able to peak 27,000 watts. It's a good thing the rear tire weights as much as two bicycles, and I have duel disc brakes at the front wheel.
Deafscooter is Here...
Deafscooter Have own E Bike ( folded Alumuim E- Bike )
I report you That Ebike is Great but Fragile the kickstand on " V Stand "
The speed Overall is Top speed is 19.5 mph Maxuim with out pedding
The Battery packs is Three SLA is 12 volts 12 Amps in Plastic Case
The Contact ( + ) and ( - ) inside the Power Input into bike Frame
If you bumper the Contact get loose then you have to Tight the packs
The Hub Motor is Stricted is 36 Volts if you attept over volts it will Burn inside Hub motor!!!
The Chain to Oneway Sprocket ( same BMX type Ratched sprocket ( only one speed )
The Speed Controller is 36 Volts at 20 Amps with Throttle as Hall Effect 0 to 5v
Ride the Folding Bike on Roadside -->> when you have crank thne motor will power ( also Crusin speed by thumb power )
crusin ride about 12 miles by own powered ( no pedding ) if you want keep pedding it will last extend range ride to 30 Miles
Most crusin speed is 8 to 12 mph on Deaf Bike Ride on last year my Friend rode whole Ride on Bike path and the battery got
Minor bumped and loose the pack then re seat the contact from battery to Frame then resuming ride to smooth bike path
Deafscooter Report this Bikes is Excellect but only problem is Battery packs, Single Speed sprocket and Fragile kick stand..
also Finger injuried if you do Folding on hinge areas and it can Break the hinge if you twistle or reckless ride as Stunt ride
Here is Picture of Alum Frame Folding Bike with 180 Watts Hub motor and 36 Volts ( show 19.5 mph Top Max speed ride..
You cannot go fast on a folding bike; it's far too dangerous. Frankly it's dangerous enough just on a regular sturdy bike, since they aren't really made for withstanding high speeds the way motorscooters or motorcycles are. But it's still acceptable; I use a $250 front-suspension Trek 820 and it's held up at speeds as high as 50 mph (but more often ~43 mph).
Also, your motor is pathetically weak and will be destroyed by high power.
I recommend a Crystalyte 5303 or 5304 hub motor with a Crystalyte 35A or 40A controller, with 48V batteries, ideally lithium-based. At high discharge currents, lead-acid loses energy more quickly than it should, so a 12Ah battery acts like an 7-8Ah battery at 40A. Plus it's heavy, affecting acceleration and hill-climbing. A lithium-based battery is the best available, and nickel-based batteries are no longer really useful because they're now more expensive than lithium while being worse in pretty much every way.
Anyway, 48V and 40A can give you a top speed of about 35 mph on flat ground with the 5303, or around 30 mph with the 5304. To go faster, you'd need more power, but Crystalyte doesn't make controllers that work reliably at higher power without some modifications.
ElectricRider.com sells a complete 48V 25Ah lithium-polymer e-bike kit for just over $2000, which includes everything except the bicycle you're converting. It's probably the easiest solution.
For the absolute best power and speed, you'd want not a hub motor but rather a motor-and-chain setup using an Etek or PMG-132 motor, though those are better suited for motorscooters and motorcycles as they're very powerful and use hundreds of amps of current.