should i buy this motor?

[qeeeme]

i bought a cheap pedelec in germany and was not happy with it there was a customer service with it they visited me and changed me the battery and the controller for free but it didnt help. so at the end i gave back the bike and lost some money on it but it was okay as now i have at home:
- 1 battery pack 36 v (3 x 12 v batteries in a pack) + charger for it
- 1 controller

as i dont know yet what is the best pedelec for me or as i hesitate to invest too big money i have following option:

- i can buy the motor for 140 euros. it is the perice the company tell me they would sell it to me

- so with only 140 euros i will have at home:

- 1 motor
- 1 controller for it
- 1 led battery for it

then i have to invest for:

- brakes
- throller
- put the motor in a wheel
- find adequate bike for it
- get a hall sensor
- put all together

it will be a lot of work but i am interested in and so i will learn more about electrical motors for pedelecsa and be able to have some assistance

- of course the question is:

- either i put 140 euros on it and start working
- or forget the whole thing, sell some day the battery with charger and forget about the controller and the 140 euros will be part of the pedelec i will buy some day

well now my questions would be:

1- did i forget something in my thoughts? will i get started with a motor for 140 euros or is something i didnt think about?
2. on the controller is written :
typical voltage: 36v maxi current: 14A
typical current:7 A under voltage: 31,5v

as you told me, maxi current of 14 A means motor is not so powerful
-what means typical current: 7A and "under voltage 31,5v"? 7 A is the "nominal" current? i mean where the "power ratio outpiu/input is maximal? and "under voltage?" it means under 31,5 v the controller stops? or it means typical current is 7 a when under 31,5 v, i means when applying 31,5 v?

3.this motor is sold in a bike with wheels 26 inches. if i put it in a bike 28 inches it is possible but less power? (okay i will not get crazy i will first start putting it in a bike with 26 inches and if all go good i can experimentate later with 28 inches)

4 at the end of the day, supposing i have been able for a small money and long time and learning process to put this parts together i will have a bike 26 inches wheels with led battery 36v and it will be heavy (let say 38 kilos as was the original bike or more) and i will have enough gears to assist it. but then the point with motor in the wheel is:
- when i dont use the motor or when the battery is empty i drive with a heavy bike (on hills important) and the resistance on the motor is always there in the wheel(?)

well the risk is to end with a motor of poor quality (but i think if i care about and know more about it i can controll what happens i mean if i dont overload it as maybe i have done with the bike i bought initially it was more designed for cheap and people not biking strongly and with too much load (i used it to drive a "small car for shopping" and maybe it was overload(?))

the other options are:
1. s flyer (3500 euros) + pay tax
2. kalkhoff agattu (2200 euros) or raleigh
3. a kit but here i start too with 400 euros
4.etc etc, think again, ... get in touch with pedelecs.co.uk etc etc

 

[flecc]

well now my questions would be:

1- did i forget something in my thoughts? will i get started with a motor for 140 euros or is something i didnt think about?
2. on the controller is written :
typical voltage: 36v maxi current: 14A
typical current:7 A under voltage: 31,5v

as you told me, maxi current of 14 A means motor is not so powerful
-what means typical current: 7A and "under voltage 31,5v"? 7 A is the "nominal" current? i mean where the "power ratio outpiu/input is maximal? and "under voltage?" it means under 31,5 v the controller stops? or it means typical current is 7 a when under 31,5 v, i means when applying 31,5 v?



the other options are:
1. s flyer (3500 euros) + pay tax
2. kalkhoff agattu (2200 euros) or raleigh
3. a kit but here i start too with 400 euros
4.etc etc, think again, ... get in touch with pedelecs.co.uk etc etc

The typical current refers to the continuous current that the controller is rated for, around 250 watts. That's enough to take you and the bike along the road at the 25 kph legal limit.

The under voltage is the point of drop in battery voltage where the controller cuts the power off. That happens when the battery is very low on charge, or if the bike is strained by a very steep and long hill which causes the battery voltage to drop too low under the strain. The cutout is for battery protection reasons.

The typical voltage of 36 volts is in fact around 39 to 41 volts on freshly charged batteries, dropping under load when the motor drives.

Given the choices you have, I would prefer to have one of the complete bikes you mention, my choice being the Kalkhoff/Raleigh models. The Flyer is good but expensive. Your controller would only supply a low to moderate powered hub motor, and without the advantage of driving through the gears like the bikes you mention, it will not be as good on steep hills, especially in a large wheel.
.

 

[john]

qeeeme, Have you had a look at www.ebikes.ca Homepage of the revolution ? They have prices and stock levels of components online and I have found them very responsive and knowledgeable in emails. Air freight is quite expensive but surface mail is cheaper if you can wait. John

 

[qeeeme]

Given the choices you have, I would prefer to have one of the complete bikes you mention, my choice being the Kalkhoff/Raleigh models. The Flyer is good but expensive. .

- for the kalkhof/raleigh models: for 2200 euros i will have a bike eliminating all the efforts at starts and at hills (i dont have big hills) and dont pay tax like for the flyer. so well i understnad it with this there will be no need more for bus and train when i am tired. one question is : those bikes offers a good assistance until 15km/h and from there it begans to decrease. at 25km/h there is no more assistance
1. kalkhof has 8 gears. in theory it is possible to put a 24 gears like flyer? the sram dual drive fits in?
2. with duch a bike it is easy to reach 20 km/ or 25km/ for me(?) and then if i reached 25km/h and i want to go faster with my muscles what happens? let say for example in a flat area, i give not so much efforts to accelerate to 25km/h and then there is a point where the motor is not giving nothing more. then what?if then i put a lot of energy cycling i go faster and faster or am i with a heavy bike which is not designed for this? at the end it is all about compromises. maybe those bike are well optimized for the money the legislations and the weight (20 kg must be there for motor and battery and
stability)

 

[flecc]

- for the kalkhof/raleigh models: for 2200 euros i will have a bike eliminating all the efforts at starts and at hills (i dont have big hills) and dont pay tax like for the flyer. so well i understnad it with this there will be no need more for bus and train when i am tired. one question is : those bikes offers a good assistance until 15km/h and from there it begans to decrease. at 25km/h there is no more assistance
1. kalkhof has 8 gears. in theory it is possible to put a 24 gears like flyer? the sram dual drive fits in?
2. with duch a bike it is easy to reach 20 km/ or 25km/ for me(?) and then if i reached 25km/h and i want to go faster with my muscles what happens? let say for example in a flat area, i give not so much efforts to accelerate to 25km/h and then there is a point where the motor is not giving nothing more. then what?if then i put a lot of energy cycling i go faster and faster or am i with a heavy bike which is not designed for this? at the end it is all about compromises. maybe those bike are well optimized for the money the legislations and the weight (20 kg must be there for motor and battery and
stability)

You could fit an SRAM DualDrive, though the chain path might be a bit extreme at the outer sprockets. That's because there is an output idler on the Panasonic unit, so the chain path is much shorter from there to the rear sprockets. This photo of it is with the bike upside down.

However, so many gears are inefficient on an electric bike, since the power smooths out the power delivery and helps bridge the gaps between gears. The eight speed hub is all you need, and you only need to change the rear sprocket to raise the gears. There will still be low enough gears for moderately steep hills if you gear it to do 32 kph at cutout by using a smaller rear sprocket on the Nexus hub gear. Of course that does reduce the range a bit, since you will be using power at all speeds, not just up to 25 kph.

The power delivery is as you say. As you pedal faster in any gear, the power reduces. That means you can still have the maximum power at any speed if the bike is geared for the slower pedalling at that speed. But of course the motor has it's limits, and beyond 30 kph a lot of energy is needed to propel a bike due to wind resistance etc.

As it stands, the power delivery has ended at 25 kph, but you can pedal these bikes like the Kalkhoff/Panasonic well beyond that since they run very much like normal bikes, and of course the higher motor drive speeds are technically illegal for an untaxed pedelec.
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