Looking to buy, can't decide what to get

[Dennyb123]

I'm getting ready to purchase a kit. I'm stuck between the 250w and 500w motor, front or rear hub? What kind of incline does the 250 watt motor climb without pedalling? Does it matter if it is front or rear hub? By the way, more torque to get me up hills is more important then top speed. Would the 500w motor be better for me?

Any help is greatly appreciated.

Thanks,
Denis

[Perbear]

The power is related to weight, functional and legal issues, so there are a few rules you can use. First you have to decide between minimotor or standard motor (direct drive):

Minimotors has built-in reduction gear and freewheel that prevent the motor from braking when coasting, but it also prevent regen. They are also about half the weight of the standard motors - minimotor at front weight 2.6 kg, minimotor rear is 3 kg while standard motors is 5 kg front/rear.
 
So if you want a light ebike that can easily be used with motor off, or live in Europe (max 250W), go for minimotor, if you need regeneration (electric brake) or more than 250W then go for standard motor.

If you decided you want standard motor, the weight is about the same for 500, 750 and 1000 W. The price difference is also small, but the battery for 1000 W needs to be 48V increasing weight (and cost) so I would avoid 1000 W. For a standard motor I would have chosen 750 W.

Thats my few cents...

Per

[Dennyb123]

Thanks for the info. I live in Ontario, Canada. I believe the max motor allowed is 500w. I do intend on pedalling sometimes. I'm thinking the mini motor should do. I'm just hoping it has enough juice to get me up inclines. Also I'm guessing my batteries would last longer with the smaller motor.

[Philip Lynott]

In my opinion there is very little point in buying a mini motor or any 250W motor because;

    -you'll have to pedal all the time to move even at a slow speed
    -The motor will be under alot of stress if you try to go up hill
    -Even my 1000W motor cannot compete with a good pure pedal power racer bicycle
     so why would you buy a 250W motor and not a good racer?

I recommend the 1000W motor because the extra power is needed for going up hill (even the 1000W motor struggles to go up hill)

The 500W motor might be ok also but I havent tried one

I have a 250W motor and in my opinion they are utterly pointless - buy a racer style bike instead of a 250W motor ( racers are possibly cheaper, alot faster, less trouble, have a greater range, no battery to lug around and charge, would require less human effort in pedaling then a 250W motor)

 

[Dennyb123]

Since I live in Ontario, Canada. The max. motor allowed is 500W. If I want to pedal the bike without electric power. How tough is it to pedal with the 500w motor installed?

[bcable]

I have used a 24V hub motor that I got through an endless sphere contact for two years with a 48V 13AH NiMH pack. I use it to commute to work (30 miles round trip). So I am probably using a "500W" motor as "1000W" motor. It works very well and I average about 25mph and have plenty of hills. By car or motorcycle it takes 40 minutes round trip. By electric bike it takes 70 minutes round trip. I pedal all the time and enjoy the ride and exercise and the extra 30 minutes is fine. The first year I covered 1000 miles and the 2nd year 1500 miles. I have done it plenty of times on a regular road bicycle but that takes 150 minutes and I am too tired when I get home to do the work around my place that I want to do. So in my opinion if you want to commute a significant distance an electric bike is the only way to go unless you like to confine you life to just work and bicycling.

My electric road bike was taking a beating on the 2 miles of dirt road before I reach pavement so I have put the front hub motor on a mountain bike with full suspension. I decided to switch to LiFePO4 batteries and ordered the 48V 20AH Golden Motor battery and controller and other accessories. My order went out about 14 days ago. I received an initial acknowledgement and said I would receive my order in 5 to 10 working days. I have enquired numerous times to sales@goldenmotor.com with no answer. So although I like the products (at least their description) the customer service leaves something to be desired. It is nice that there is this forum to exchange experiences and knowledge.  Bill Cable Cornish NH USA

[architect]

Hi,

i have a 500w 36v front wheel setup with 3 x 12v 7ah sla batteries.... it works fine it does go up hill with a little peddaling but feels the same as going on a flat road. If I was to upgrade I would change the controller over to a 46v and add an exstra battery.... this would improve both speed and torque.

if I was u go for the 500w with a 46v controller and it should do everything u need with a little peddaling on really steep climbs.



cheers.

[Perbear]

I have a 250W motor and in my opinion they are utterly pointless - buy a racer style bike instead of a 250W motor ( racers are possibly cheaper, alot faster, less trouble, have a greater range, no battery to lug around and charge, would require less human effort in pedaling then a 250W motor)

I have converted a hybrid with 28-700C tires, Shimano 8-speed hub gear, magnesium front suspension and belt gear, not chain. The front wheel was replaced with a 250W minimotor eqipped with 700C rim and heavy gauge spokes and a 32-700C tire. I have added a home made torque arm made of titanium and duplex for safety. The battery is a 36V/10Ah GM Li-ion that last about 35 km (approx 10Wh/km).
 
In use, this EPAC (Electriacally Power Assisted Bicycle) with tires inflated to max pressure, has a max speed of 30 km/h, that is 2.5 km/h above legal maximum (25 km/h + 10%). When I put in moderate effort I manage 20 to 30 km/h going uphill at modest hills. At steep hills (10% or more) I travel about twice as fast as I do without motor.

I agree that the bike needs pedalling when going up hills, as Philip said above, but:
It is a legal requirement here in Europe that you need to pedal for the motor to assist at speeds above 6 km/h so it is the way it is supposed to be and thus it is not a problem in Europe. The real problem is the PAS sensor and control algorithm of GM Magic Controller - it is so awful so I do not use it. But their implementation is illegal anyway since it has to be manually activated (I am working on developing a small controller board that will fix this but it is not finished yet).

Per

[Dennyb123]

Hi,

i have a 500w 36v front wheel setup with 3 x 12v 7ah sla batteries.... it works fine it does go up hill with a little peddaling but feels the same as going on a flat road. If I was to upgrade I would change the controller over to a 46v and add an exstra battery.... this would improve both speed and torque.

if I was u go for the 500w with a 46v controller and it should do everything u need with a little peddaling on really steep climbs.



cheers.

How easy is your bike to pedal when not using the electric motor, compared to a regular bike?

[Philip Lynott]

Hi Per,


I have a motor running at 1000W this gets me to around 50km/h, even at this speed I am regularly overtaken by cyclists on 'racer' style bicycles with very light frames high gearing and no suspention.

I can't see the point of spending time and money on an ebike which is slower and at least as difficult to pedal as a good 'normal' bicycle. A normal bike can be used for competitions and group cycles where the distance is in the 100s of kilometers - ebikes can't take part in these things.

If the european government was serious about reducing europe's carbon emissions they would allow 1000W motors as per californian rules. If they were to do that they would need some kind of testing system for DIY ebikes because they are potentially dangerous.

[Perbear]

I have a motor running at 1000W this gets me to around 50km/h, even at this speed I am regularly overtaken by cyclists on 'racer' style bicycles with very light frames high gearing and no suspention.

I arranged a hill climb competition here in Norway that ended up on TV and in newspaper, and the "pro" carbon fiber racer won, but that was because my son who was leading the race, missed a turn and took a long extra detour. Actually, the ebike was fastest up the hill (about 1 km).

I am certain that it is possible to build a legal EPAC that can not be beaten by normal racer, i.e. have better times with the same cyclists on a hilly tour. You would need freewheeling and as light motor as possible, slim and light spokes and rim, 20x700C tires, a very light LiPo battery (that unfortunately has reduced lifetime compared to LiFePo4) with 10 wh/km (i.e. 100 km requires 1kwh). The added weight is only a drag going uphill, and if the speed is less than 30 km/h you will benefit from having the motor, and the extra weight is beneficial going downhill.

Maybe this race in Norway, 9. August 2009 going from Lysebotn to Bryne would be a nice test: http://www.brynecykleklubb.com/aarbakke/index.htm

Hi GM - I can build a bike but I need a sponsor! :-)