Overstating Specs?

Hi, I'm really interested in a 1500w 48V kit. The specs and speed specs just seem excessive. Can anyone comment? I'm upgrading from my initial 300W kit.

http://www.leafbike.com/products/diy-bike-conversion-kit/28-inch-electric-hub-motor-kit/newest-28-inch-48v-1500w-rear-hub-motor-bike-conversion-kit-990.html

Thanks!

Not impossible, but not bloody likely unless they dropped it off the roof. In order to break 40mph with a 48 volt battery, you would need a very fast wound motor, which would suck down Amps faster than Monica Lewinsky sucks down.. Errrr, hot dogs, or some other family friendly metaphor. You get the idea. It takes around 2500 watts to do 40mph. at 48 volts, that's 52 amps at cruising speed. It would very likely suck down much more to accelerate up to that, meaning the controller should supply at least 80 amps. They claim it's a 12 FET. That's not impossible that it could be modified to do that, but it would have to be modified.

Their 90% efficiency claim is also dubious at best. 90% efficient at fooling people, maybe.

43mph is the unloaded speed I suspect. So loaded speed would be much closer to 35mph MAX on flat with no headwind for reasonable weight person.

Just know what you are buying. So I don't see any false advertising here. They just don't mention what those conditions are for the 43mph.

Play the video and you will see it's with the wheel off the ground. Actual on the ground speed will depend on many factors. It does have a 40A controller, so at least it's not that weak.

Thats what I was thinking. I really want to hit 50 maybe 60 km/h and all the roads I take to work are basically flat tarmac. So no uphills and random inclines. I'm assuming this could reach 40-50 km/h? relatively well?

Im reluctant to go for a 72V kit cause the batteries are quiet expensive. My current bike is only 15 AH, 300 W circuit. It's my first one and its been working great. I just wish I could go faster on the long straight streets and its barely able to go from a complete stop to a rolling pedal without alot of torque fro me.

Any suggestions would be great

It should have no problem hitting 60kph on flats with a decent 48V battery pack. Just make sure the battery pack you get is capable of 40A ouput.

I already have some LiPo batteries laying around. I was just wondering would the torque on this motor be enough to go from a stand still to a rolling speed without user input? I hate stopping at lights and pedaling like mad to get going.


Thanks in advance.

It's an extremely fast wind motor, so it's not going to be the best for off the line torque, but with 2000W power, you shouldn't have to pedal off the line.

Thank you very much, this is my first custom build. My first bike was pre-built so I never had to match and assemble parts. I dont mind pedaling a bit but with my current I really have to put alot of force to get going. What type of battery pack would you recommend t oget the maximum performance out of this motor? The 2000 and 3000w hub motors are nearly triple the price, so I'm trying to avoid going up that far.

Thanks

You can us 12s-15s lipo with their controller.

I did find a kit, but the controller is only rated at 35A although I don't want to have to order a million separate packages.

Would this shortcome and performance from the battery?

35A at what voltage? VA=W, so it may be more than enough depending on the motor. With a 50V source, that's 1650W.

35 amps through any medium price direct drive hubmotor will be plenty perky, no need to pedal.

I'd not recommend the extremely fast winding for a 26" wheel, but the slightly fast versions such as the Yes 1000w kits are not bad at all. They are faster, but not stupid high rpm. You'll never have to pedal hard.

I'm the guy here constantly pushing people to obsess less on speed, and use slightly more efficient rpm motors. It's just amazing how much those faster winds waste on a stop/start. Those less than 400 rpm spec at 36v. No need for most to go to 200 rpm. One common winding is the 9x7 or 2807 (370 rpm). It will do about 27 mph cruise on 48v with only 20 amps, and still do ok off the line. Really perk up at 40 amps 48v, and likely reach 30 mph (48 kph).

30 is plenty for a bike, if you need more for street use, I just say get a Honda. And not because I never did it, I built a bike that did 47 mph. Too much for bike tires to do that speed all the time. Fun to have 40 mph, but you should do most of your riding slower, for a lot of safety reasons.

Woah, definitely not trying to go past 60km/h. I just want to be able to ride along traffic without being a nuisance and causing cars to drive around me down since I take one very long street to work and the gym everyday. This set up is right in my price range and those head winds destroy my current bikes torque.

How would I estimate the range on such a setup? 48v 1500w hub + 20AH 48v LiFePO4 battery pack.

At 60 kph, your range will suck. Wind drag will eat it up. Think 60wh/mile or less. 1000wh, about 16 miles hauling ass. vs 40 miles if you rode under 20 mph.

In between, you should be able to ride 40- 50 kph in the 40wh/mi ballpark. 25 miles. 40 km.

Thanks alot, you helped clear up any worries I had. On my busiest days I only travel about 30 km max. And most days its 12 km.

I just hate sitting in an empty road going 20mph when I could be goin a few miles faster.

Do you need a 28" wheel or 26"?

Listed is a 28" and that isn't cheap. Shipping is always high now a days.

Dan