Geared Motors for Chain Drive Systems

These motor kits have the basics to make a chain drive system

1. Basic Kit 1: $150aud and $60aud freight
 24v  smaller motor /controller 24v30amp/ throttle/ rear mounting bracket

2.Basic Kit 2: $170aud and $70aud freight
36v  mid size motor /controller 36v/30amp / throttle/ rear mounting bracket ( requires drilling holes to fit this motor)

3.Advanced Kit 1: $250aud and $80aud freight
24v  smaller motor /controller 24v30amp/ throttle/ rear mounting bracket/cyclone freewheel pedal sprockets/freewheel sprocket on motor
(note adapters for freewheel sprocket on motor wont be ready until mid September 2007 so can only supply motor with non freewheel 9 tooth sprocket for time being)

4.Advanced Kit 2: $270aud and $90aud freight
36v  mid size motor /36v/30amp / throttle/cyclone freewheel pedal sprockets/freewheel sprocket on motor/rear mounting bracket ( requires drilling holes to fit this motor)
(note adapters for freewheel sprocket on motor wont be ready until mid September 2007 so can only supply motor with non freewheel 9 tooth sprocket for time being)

Info on Motors:

1. Smaller Motor
These motors can be used to drive the chain directly via the rear gear cluster or via the front pedal sprocket. This allows the motor to be used over a large range of speeds and torque by being used via the gear change system so the motor can drive the rear wheel through different gear ratios.
In my view a hubmotor is a simpler more reliable system and the main reason for going with a chain drive system would be to get very good torque for hill climbing in the lowest gear of the bike.

Below shows the smaller 24v motor. There are two versions a 24v version and a 36volt version. Both versions can be overvolted the 24v can be run on 36v for higher top speed, and the 36v can be run on 48v. The motors can handle currents of 30plus amps without overheating.

Specs below:

Below shows how Rob of Victoria Australia used the smaller motor and adapted the mounting bracket for use on his bike. Rob is using the 24volt smaller motor, he has recently run it on 36v which these motors can also handle no problemo.

 

Below shows how the mounting bracket is originally intended to be used ( on left or right side of rear wheel). I include it in the kit as it may be useful for using the bracket when making up mountings in epac or elation style mounting of motor. I will have some mounting brackets made up at a later date for now will be up to customer to make up mounting brackets so is quite a bit of diy involved with these kits at the moment.
 

2. Mid Sized Motor

Mid sized geared motor: 36v 30amps ( rated power 350watts peak power 750watts )

Below shows how Ray of Laurieton NSW Australia used the mid sized motor.

Larger more powerful motors are also available:

Large geared motors: 48v 20amps ( rated power 450watts peak power depends on controller but generally over 850watts ). This motor is commonly used in mid sized trikes in china. They tend to use 4 lots of 20amphour battery packs in quite heavy duty trikes. It has a drive sprocket on the motor ( with no freewheel ) but the drive sprocket suits a motor bike size chain which is larger than bicycle chain. Its a more heavy duty motor for midsized threewheelers. Will put more details up on this motor as time permits. This motor is quite heavy about 5 or 6kg.

Three commercially available ebike kits ( Epac and Elation one bike use the small motor above, Cyclone use a more advanced motor design which is brushless with planetary gears) are shown below and how they mount the motors.
Kmart was also selling an ebike using the smaller motor ( no pic available as yet ).

1. Epac kit: pic below shows earlier model epac kit with no freewheel on the motor gear.

2. Elation ebike kit ( pic from visforvoltage forum....I think! sorry had no other pics of it had to borrow this pic, sorry to the author of the pic for using without permission)

3.Cyclone made in taiwan. insert shows the controller located inside the motor, very well built motor uses a planetary drive system also inside the motor housing.
Note in the pic below the chain normally goes around the white nylon gear but in this case is being used as shown .

A little history of the smaller motor: I first became aware of this motor being sold by oately electronics some years ago. It proved very popular and reliable motor and many ebike enthusiasts seemed to be experimenting with this motor. Shortly afterwards Epac bikes of Forster, NSW, Australia starting using this motor in early versions of an ebike they were trying to commercialise ( a process that continues ). The downfall of the earlier Epac system was the pedals would always rotate when motor power was supplied. This issue has been resolved in later models with the addition of freewheel systems on the pedal cluster and on the motor drive gear.
This is quite an important issue as I think it is a bit dangerous having the pedals spinning all the time when the motor power is on, and I found when riding an epac bike that it was really quite challenging having the pedals rotating all the time when motor power is on.
{An example of one incident was relayed to me by Ray of Leuratan, NSW , Australia (on the 31st of May,2007) in his experiments with a mid sized geared motor I supplied him with. He was coming up to a roundabout and the power go stuck on full throttle ( reason not determined as yet ), so he had to go around this roundabout on full throttle with pedals going flat out, he had to take his legs off the pedals and handle the turn as best as he could. He managed to hold on to it and the pedals didn't hit the ground fortunately.}
Later Elation in Melbourne brought out a kit using same smaller motor but using cyclone pedal freewheel system.

The output power from the motors depends on the controller used. Typically they are using 30amp controllers for the oatley motors ( using Power = voltage times amps times efficiency (70%approx)) the peak powers are: 24v motor: P=24*30*0.7= 504 watts, 36volt motor: P=36*30*0.7=756watts ( the motors are rated at 250watt or 350watt by the company, that is the continuous power, the peak power is much higher though, I find peak power is very useful for determining the power of a motor as you tend to find that you will be using the motors at full power for a large amount of the time of a bike ride).

Cyclone in Taiwan is another version of a geared chain drive system. Probably the most successful system as it seems to have been a popular seller in many countries. It uses a brushless planetary geared motor ( of very advanced design ) below the pedal crank driving the chain, and uses a freewheel on both the motor output gear and on the pedal crank.

One more company is using these same motors on commercial ebikes which was  being sold by Kmart in Australia, where the motor drives directly onto the rear gear cluster ( well its another gear they put on the opposite side of the rear wheel to where the normal rear cluster goes ). So there is no gear change for the motor to go through but seems to work reasonably well. The plate that they use to mount the motor on these bikes is included with the motor kits, I haven't had any mounting brackets made up in epac or elation or cyclone style mountings so you'll have to make your own mounting brackets or adapt the bracket that comes with kit . I will at a later stage have some purpose made mounting brackets but will take some time to organise that.

Advantages/Disadvantages over hub motors:

1. hub motors are very quiet some pretty much completely silent. Geared motors via chain do make quite a bit  of noise.
2. having to be completely reliant on changing gears for the motor to drive correctly, is quite a bit of work when riding. It doesn't always go to plan, sometimes your not in the right gear etc, also I found that you have to come off the throttle a bit for nice smooth gear changes, so some learned skill involved.
But the biggest difference is this: with a hub motor there is no gear changes, so you dont really have to change gear all that much for pedalling, you tend to rely on the motor alot. But this allows you to have very nice throttle control, I find that I am constantly adjusting throttle so that my pedalling is not forced, its quite easy to be able to ride along adjusting throttle so that pedalling effort is very light or as much as you want to exert. With a geared motor via chain that is more difficult as you are having to go through all the gears to keep motor on right gear setting for your speed, its just more things happening at one time your brain has to deal with, for me personally hub motors are much easier.
3.maintainence: when driving a motor via the gear system there is alot of wear and tear on the chain/gears/freewheels. The amount of force on the chain and cluster is very large, if you can imagine you can yourself supply 200watts of power without too much  effort, then apply this by about 3 times ( the max. power output of the geared motors ), and theres alot of banging and crunching going on especially during gear changes with motor power on. So there are problems arise in the commercial systems ( cyclone,elation,epac) where parts need replacing prematurely due to the forces at work ( some problems that I've heard of are chain breakages, freewheels wearing out early and more rapid sprocket wear ).
4. advantage of geared motor system is that on steep hills you can get really high torque using a low voltage system, so you can climb up very steep inclines without pedal assist, but will be going very slow of course. You can do the same with a hub motor if using lithium batteries, you can get the same result but you need to use a higher voltage system ( more power ) to get the same result. I recently did a test comparing a cyclone system 24v, to my 408 motor ( 48v ) on steep hills that were pretty much identical but I was using about twice the power on the 408 as compared to the cyclone. So for very slow going and steep hills is where I think the geared motor systems have a big advantage.
5. geared motor systems are a bit less efficient than hub motors generally
6. doing some test rides against cyclone kit compared with 408 motor top speed of hub motor much better than chain drive.

Below: summary pictures of how each system on the market is configured

 Epac system  (Forster, Australia)            Elation System (Melbourne,Australia)                     Cyclone System (Taiwan)

 Some notes on each style:

1. Epacs' original system drives a sprocket on opposite side to the pedal sprocket. . The newer epac system drives the right hand side pedal sprocket
2. the elation appears to use the cyclone pedal crank/freewheel system
 

I have riden both cyclone and epac bikes and I was very impressed with the hill climbing abilities, can pretty much go up whatever you like in lowest gear, top speed was a bit slower than a gearless brushless hub motor but still quite good to ride. Changing gears you really need to take the throttle off a bit like a clutch, there is a bit of technique involved in getting smooth gear changes. Its certainly harder to ride than a hub motor with no gear changes necessary but for hill climbing very impressive systems.
You can build a system without using freewheels, I rode an epac version without freewheels on pedals or motor and I found it a bit dangerous to have the pedals always rotating when the motor is on ( especially on corners ). Since the chain will be getting power from a motor and from pedal assist ( possibly ) the components will have more forces on them than normal and over time there may be some issues with premature wearing of bearings etc. So regular lubrication of bearings  will most likely be necessary.

beware of spray ebike company: more info