36V Electric w/ shifting

[Axlerod]

Greetings: I just finished a Custom Electric MTB. 36V-600W Motor synchronized w/ pedals @ ~ 70 RPM. Nice crusing speed ( ~ 28 mph my guess) & easily climbs any hill. If you use the throttle , you must pedal, but if you want to pedal you can w/o turning over the motor, and it coasts really fine. I need to install a computer on it to see range & speed. Also 3 lead acids @ ~ 8 lbs. ea are a heavy load. Bike wgt. 62 lbs. A LiFePo4 battery would knock off ~ 16 lbs. w/ single frame mount. @ 46 lbs. much better.
Most electric bikes I've seen have motor geared for one speed. Where I live it's very hilly so performance and range of electric bikes are adversely affected. Gearing the motor has a dramatic positive impact. Any EB'ers w/ simular observations. Has anyone seen or made a simular set-up?

Thanks Gt reynolds

 

[Axlerod]

36V-600w E Pic's

Schwinn MTB w/ LIPO mockup battery pack. I'm currently running w/ 3 12V 12 AH lead Acids.

 

[safe]

Is that one of the ebay (taken off the open market) Currie motors?

http://shop.ebay.com/motor-generator04/m.html?_nkw=&_armrs=1&_from=&_ipg=25

If not, you ought to seriously consider upgrading to one. They use real Neodymium magnets and are significantly stronger than stock. I use one on my older bike.

Multispeed gearing is a great way to go. I have a bike that I first built in 2006 using a six speed derailler and I now have over 8000 miles on it. The multispeed gearing allows full power no matter what the conditions.

Good build!

Note on the ebay motor:

The motor is so strong compared to stock that they built a bunch of them and decided not to sell them for liability reasons. (didn't want some kid to fall off a scooter) It's a worthwhile investment to upgrade if you aren't already there.

 

[Axlerod]

Motor

Yo Safe: Thanks for the info on the 1000W Currie. It looks like it would really boot. The 600W motor I am using is a Currie, & it seems to have the good magnets. I can just barely turn the shaft by hand w/ 11 tooth cog w/o tearing up my fingers. Not sure if I need any more power, cruising ~ 30 mph seems good for now, but if I have a need for speed it would be fun to try.

 

[safe]

The stronger magnet Currie motors are not being sold to the public.

In order to get one you need to go through this guy in New York that bought up the entire discontinued batch and is selling them through ebay.

The stock Currie motor isn't bad, but if the typical stock motor can produce 600 watts for a given voltage this one is able to achieve 1000 watts.

He's selling them at a good price too... usually if you get one without having to compete in an auction they are $49 plus $20 shipping. It's a good deal because many of the retail companies sell the stock Currie motors for $100.

Think about it... maybe after you upgrade batteries you would want to upgrade the motor too. (depends on spare $$$ I suppose)

Note:

The ebay Currie motor is rated:

24 volts - 1 hp (750 watts output) Controller should be 24V 40 Amps

36 volts - 1.4 hp (1000 watts output) Controller should be 36V 40 Amps

...I've been running mine at 48 volts which "could" achieve 2 hp, but I've reduced the current limit to 20 amps so that the motor runs nearer to 1 hp. It runs cooler this way. You could buy the motor and run it with the same controller you now have (probably 36 volts and 30 amps) and it will run stronger, cooler and more efficient.

 

[Axlerod]

Endurance Run

Saturday morning I made a run to Manchester from Derry, NH. 15 mi ea way. Met w/ some friends, ate breakfast then made return trip, total 30 mi. Plenty of hills. I coasted down some of the hills but pedaled most of the way. The last 3 mi I could tell I was losing power on the hills so I downshifted. W/ energetic pedaling I could still keep a good pace on the flats. W/ the extra wgt of the E Bike I noticed that it would coast nicely when I shut off the throttle. I am currently running knobbies, & I plan to upgrade to some smoother tires ASAP, this will help it to coast even better. This is promising. I have ridden this same route many times ; on my road bike & it takes me just over 1 hr, w/ the electric MTB bike it took 40 min. By auto it takes 30 min. for 15 mi trip.
I need to mount a computer & see how performance holds on a flat run. It is difficult to quantify the hills, they really seem to consume a large amount of power. Sure you can coast on the down hills but energy demand is high on the up. There is a 1/2 mi oval track that I can do a controlled endurance run, w/o hills & stops & starts. I'm sure others have done simular experiments. What performance have you gotten? ie: ave speed, dist, Type motor V, W, batteries type ,& A/Hr.
Can anyone recommend a good low cost Li Po Battery source? 36V ,12 AH

 

[veloman]

If anyone wants one of those 1000w motors that Safe is talking about, I got a couple extra one's I'll sell for $50 each shipped in the US. I bought 3 from that NY guy and really only need one....

pm me

 

[machiasmort]

What do you need a controller for? Whats wrong w/ a double throw switch like in the cartoons?

Safe has got his degree from the ACME institute of drafting, he should know the kind I'm talking about...

 

[Garp]

I'm interested in running my gearbox with an electric motor. Using gears would make an ebike a lot better. A single ratio transmission requires more power to be useful.
At the moment I'm running A Honda but its too noisy for me, I want to hear the birds when I'm riding through the bush.

 

[pbeggs]

axelrod,.. the only thing i can see you are missing is a freewheeling crankset so you can use the motor without pedaling,.. otherwise nice build!!!!!