Standard Controller

David, this is the picture of the standard controller.
If you need more info, let us know.

Some wires have overheated

After riding the bike for 15-20 minutes (at full power most of the time), I've noticed some heat under my ass. I've stopped and seen that some wires were very hot, and that the fuse cover was melting. The fuse cover was close to the battery pack, so the tape around the battery pack has been sligthly damaged, too...



Still analyzing the root cause, but it seems that the wires (that actually came with this 20Ah battery) are too small and we should install bigger ones (more section). But the battery should come with proper wires, shouldn't it?

Pedelec sensor not recommended

After some trials with the Pedelec sensor, I do not recommend it (at least the one I tried).

I found two main drawbacks:

- First of all, it's not a progressive system. I thought that the faster you pedaled the more power the motor would supply. But, it's not like this. If you move the pedals (no matter how slow), you have full power from the beginning (there is a 1 second delay). If you stop pedalling, the motor stops completely (with a 2 second delay). This is not a good thing when it comes to comfort and battery life.

- It takes about 2 seconds for the motor to stop once you have stopped pedaling. This is really dangerous with a 1KW motor. It has some delay (about 1 second) when starting pedaling, too, but this is not really a problem (you get use to it easily).

To sum up, I was really disappointed with the Pedelec system. It needs lots of improvements (we may develop our own Pedelec system in the future).

Installing the Pedelec sensor

Thumb throttle works perfectly.



Now, we want to try the Electrical assisted pedaling using the Pedelec sensor.

It consists of a disk with 5 magnets and a sensor to detect the movement.












I was not able to remove the pedal until I used an extractor.















The sensor (with the plastic side looking outwards) is fixed with the shaft nut (which needs to be removed first).









Then the disk with the magnets is inserted in the axle. But, surprisingly, the sensor detects the direction of the movement, so the disk has to be inserted as in the picture below. Be careful with this, otherwise, the motor will start only if you pedal backwards (which is funny, by the way).

Finally a picture of the sensor and disk properly installed.

Some pictures

Motor in rear wheel with only one gear.


Regenerative controller (the one with a label) versus regular controller.


Battery pack (48V 20Ah) with Battery Monitoring System (blue). Size is 31 x 14 x 18 (cm). Around 10 Kg.


Battery pack, regenerative controller and battery charger.


Charging the battery pack for the first time.

Interesting links

http://www.electricbicycleworldtour.com/en/

http://www.ev-network.org

Battery pack received

On Tuesday July 28th we have received the battery pack (48V) and the charger.

It has taken 15 days, but it was actually shipped 3 days after the kit, so shippments from Shanghai to Spain take around 10-12 days.

The material seems to be in perfect condition. The battery voltage is 53 Volts, so we decided not to charge it before using it.
The only drawback is that the battery pack does not fit in the bag that was provided with the kit. I guess the bag is thought for the 10 or 15Ah battery pack, not for ours (20Ah).

The wheel was already mounted, so we have connected all the wires and needed components (brake levers, thumb throttle, regular controller) and the battery pack, and have switched it on for the first time.
It works perfectly! And how powerful the motor is! It's virtually impossible to stop the wheel, even with the whole weight of our body.
You should have seen the EV grin in our faces... (EV stands for Electric Vehicle).

But a lot of things are still pending: looking for a proper way to hold the 11kg battery, trying out the pedelec sensor, trying out the regenerative controller, ...

We are having fun!

Disassembling the gear bearings

Once we got the tool to unscrew the gears from the wheel (picture), we confirmed that the bearings were completely damaged.

We couldn't find a set of 5 gears (as the original one) to replace the damaged one. We've only found sets with 6, 7, 8 or even 9 gears, but they wouldn't fit because they are wider. So we have finally mounted 1 gear only.

It's quite strange to see a mountain bike with only one gear in the rear wheel, but this is what we have right now.

Next surprise: the gear we have mounted is wider than the chain. Did you know that bike gears are available in different widths? Neither did we. We are actually asking ourselves if we really got a bicycle gear... Anyways, the width of a gear is nothing that a miter radial saw cannot reduce...

After some hard work, finally the wheel fits in the bike (and the chain in the gear;)

Just waiting for the battery, now.

How a brushless motor works.

This is a good document that explains how a brushless motor works and how to design a sensorless driver.
Despite our driver is a conventional driver, with several extra wires, this document gives a good description of the motors used in electric bikes.
http://spsis.com.ar/electronica/back_emf_tesis.pdf

Material received

On Thursday July 23th, we have received the kit: rear wheel (26'') with electric motor and 5 gears, 2 controllers (regular and regenerative), thumb throttle, pedelec sensor, brake levers, and a bag to carry the battery and the controller).
It has taken 10 days. Not bad.
Everything seemed to be in perfect condition, but when we have started assembling the components, we have had two problems. One is a small issue, but the other one is a show-stopper:

• The rear wheel, when mounted, was not exactly centered. It was slightly shifted to the left (the gears are on the right hand side), so it was not possible to mount the rear brake (the left pad was always in contact with the wheel). We have been able to solve this problem (at least partially) by smooting out the hole that holds the wheel axis.
• The big problem is that there is something wrong with the gear bearings: the gears are stuck to the wheel. So, the only way to ride the bike is not to stop pedalling (not very nice in an electric bike, by the way). We need now an special tool to disassemble the gears... Damn!