Philippines Pedicab (Trisikad) Conversion

[rbscebu]

This is the first post of probably many more in this thread on my planned conversion.

A Philippines pedicab consists of a heavy-duty 20" diameter wheel direct drive bicycle with an unsprung sidecar seating up to three passengers plus a bit of luggage. Fully loaded all-up mass is about 250kg.

This project is to fit an electric drive hub to the sidecar 20" diameter wheel to convert the pedicab to electric drive with peddle assist.

I have laid my hand on a 26" diameter rear wheel with 1000W X 48V direct drive hub and all the associated gear, except for the batteries for about USD250 (budget is limited). I should have this rear wheel assembly within a couple of weeks. Before then, I'll post some photos and details of the pedicab.

Should be an interesting project. I hope some of the members here can later give me some guidance and advice.

 

[rich c]

A gear hub motor would likely have been a better option for the better torque. Have you laced wheels before? Getting the spoke length sized correctly always intimidates me.

 

[harryS]

Those look like fun. I want one.

In my area, the pedicabs are like tricycles, so you could never mount a rear motor. What the tour operators do is mount a big front drive motor, and some have an addition bafang mid drive helping out on the rear wheels.

I have no experience with direct drive motors, but the above guys get by with one in front and they carry 2-4 passengers.

 

[Trail Cruiser]

This is the first post of probably many more in this thread on my planned conversion.

A Philippines pedicab consists of a heavy-duty 20" diameter wheel direct drive bicycle with an unsprung sidecar seating up to three passengers plus a bit of luggage. Fully loaded all-up mass is about 250kg.

This project is to fit an electric drive hub to the sidecar 20" diameter wheel to convert the pedicab to electric drive with peddle assist.

I have laid my hand on a 26" diameter rear wheel with 1000W X 48V direct drive hub and all the associated gear, except for the batteries for about USD250 (budget is limited). I should have this rear wheel assembly within a couple of weeks. Before then, I'll post some photos and details of the pedicab.

Should be an interesting project. I hope some of the members here can later give me some guidance and advice.

Please send photo of your unfinished build. The 20 inch wheel may give you adequate startup torque specially if you use it on a generally flat road. However, you may need your passengers to give a startup push when going up a hill. Ideally, you would require a geared hub motor but once it is moving, the direct drive should be adequate.

You don't need high voltage, it will only give you higher top speed. You need higher amperage for more torque. Cheap E scooter lead acid batteries can do the trick and provides good counter weight on empty load.

https://www.amazon.com/PowerStar-2P...d=1536694834&sr=1-10&keywords=scooter+battery

 

[rbscebu]

The following are some photos of the pedicab to be modified.




LH Profile with the driver Erwin in the background. That white animal bottom left is the only girl who truly loves me unconditionally. The motorcycle is my Yamaha YBR125G.




RH Profile



Front Wheel



Left Wheel



Right Wheel

In my next post, I'll give some physical characteristics of the pedicab and its current operation.

 

[Trail Cruiser]

What is the unloaded speed/rpm at 48 volt and 20 amps?

 

[Trail Cruiser]

you have enough room for 4 motorcycle lead acid batteries under the seat, which is perfect for weight distribution. You will need a charger that max out at 54 volts, A 2-3 amp charger is gentle to the batteries and help prolong battery life.

 

[harryS]

So how will you stop ? Looks like you have one roller brake on the left side of the driver side wheel. If it mounts using the same bolt pattern as disk rotor, perhaps it can fit on the hub, but I think you will need more than that. for the higher speeds that will result. I would suppose there is a speed limit for this pedicab. 15 mph?

Mount center pull rim brakes on the front wheel? There appears to be a bracket there, but that could tear off with the weight that you are carrying. A better approach is to weld on the tabs and put a disk brake in front, or buy a steel fork that has the tabs. As it is a direct drive motor, you can upgrade to a controller that supports regenerative braking, but you still need a hand brake.

I hope the axle on the hub motor is long enough to handle the rear sidecar attachments.

 

[Trail Cruiser]

Once you find out the unloaded rpm at 48 volt and 20 amps (or whatever power source, such as 36 volts and 20 amps) I can run it to a simulator and I can deduce the other performance parameters such as the torque, max loaded speed, etc...

 

[rbscebu]

Thank you for all the comments so far on this project. They are much appreciated.

I am treating this as an engineering project, so the first job is to gather as much of the needed information as possible. Once obtained, I will then start looking into who the project can be executed and address any problems that may arise.

Pedicab Current Physical Characteristics

Construction Material - All of steel (frame, wheels, spokes, handlebar, cab frame, etc.)

Braking - Cable operated hub brake on left wheel only

Wheelbase - 1,015mm

Track - 1,055mm

Tyre Sizes - 20" x 1.75" (front), 20" x 2.125" (left & right)

Axel Loads - Empty: 15.2kg (F), 16.7kg (L), 20.4kg (R) [Total mass = 52.3kg]
With driver (76.5kg) only: 44.0kg (F), 65.8kg (L), 19.0kg (R) [Total mass = 128.8kg]
With driver + 50kg pax: 49.4kg (F), 80.3kg (L), 48.1kg (R) [Total mass = 178.8kg]
With driver + 100kg pax: 54.9kg (F), 96.6kg (L) 77.3kg (R) [Total mass = 228.8kg]
With driver + 150kg pax: 60.3kg (F), 112.1kg (L), 106.4kg (R) [Total mass = 278.8kg]

Max. Torque at left (drive) wheel - 52.7N.m

Note: Driver states that he usually limits the total mass to under 250kg. If it is much over this, he is unable to start (without assistance) on the inclines experienced during his trips.

Next will be to determine the pedicabs typical rout information. I hope to have this within the next couple of days.

 

[Trail Cruiser]

Right off the bat, it needs 2 additional brakes, you can easily install rim brakes to the front and to the side car. Safety first, especially that it will be heavier with the motor and the batteries.

You also need to limit the speed to about as fast as the non motorized version. It's the lack of stopping power that will likely put you into an accident.

Once you provide me with the no load RPM at 20 amps on 36 or 48 volts, I can plug the numbers to a simulator and provide you with the rest of the performance figures and I can also recommend if you really need 48 volts or if the 36 volts will suffice.

I have experience with both lead acid batteries and lithium batteries. For the same energy capacity, the lithium battery can be about 5 times more expensive, and if poorly made, it can be a fire hazard that can burn down your house. The lead acid battery is heavier but it is more resilient and does not require battery management system.

 

[rbscebu]

Hub Motor Specification

The kit is sourced from China with a recommended price of about USD360 + shipping (about USD10 from China to Cebu, Philippines). I managed to buy it on special at USD255 including delivery. The kit package includes:

1 x Motor wheel (inner tube is not included)
1 x Contact wires
1 x Brake levers
1 x Thumb throttle
1 x Winding pipe and hambroline
1 x Controller
1 x Battery bag

Kit description:

* Complete electric bicycle kit includes everything needed to convert your standard bike into a top-of-the-line performance electric bike.
* Suitable for mountain bike road bike and leisure bike.
* 48V/1000W super power brushless geared hub motor.
* Aluminum alloy powerful controller.
* Low noise quiet operation.
* Nylon tire and alloy rim and stainless steel spoke.
* Rare-earth metal magnet are used in the motor to efficiently produce large power.
* Twist throttle has battery level display and power-cut off button.
* Brake Levers cut off the power supply to the motor safely.

Specification:

Wheel type - Rear Wheel
Motor - Brushless Gearless
Tire - Nylon
Rim - Alloy double wall
Power - 1000W
Voltage - 48V
Torque - 15N.m to 35N.m
Rated speed - 480rmp
Suitable aluminum wheel size - 12", 16", 18", 20", 24", 26", 700 c, 28"
Wheel size - φ650mm
Bag size - 400x180x200mm
Controller size - 185 x 50 x 80mm
Mass - 12.2kg

Some photos of the kit (delivery expected late September):

 

[Trail Cruiser]

Four hundred eighty RPM rated speed is a fast wind motor designed for speed (28 mph or 45 kph) and does not have adequate torque (only 35 NM max), even with a smaller diameter 20 inch wheel. You need at least 70 NM of torque.

Thirty five NM is too small and will likely use too much amps (easily drain the battery) on startup with risk of overheating

This does not have enough torque for start up and hill climb and can be dangerously fast on the flat or downhill.

You need a motor with low speed winding or a geared hub motor. If you can negotiate with the seller for an exchange, that will be my recommendation.

You also don't need the sprockets, so maybe you can also save money there.

 

[rbscebu]

Now that I have accumulated a bit more information on this project, I will start asking some questions.

The pedicab is to be pedal assist, meaning at startup and possibly on inclines, the driver will also be pedaling. It also needs a range of about 40km on flat terrain. Although not yet determined, I expect the maximum incline for this pedicab to be somewhere between 1% and 2%. To keep battery capacity and cost down, the driver will be providing pedal assist for about 50% of operations.

My first questions are regarding the hub motor. The pedicab will only need a maximum speed of about 15kph to 20kpm (engine speed of about 150rpm to 200rpm) but will require maximum torque, particularly at startup.

1. The motor is rated 40VDC 1000W 480rpm and torque of 15N.m to 35N.m. Why the variance in torque and what determines the torque; voltage or current?

2. I have read that the speed (rpm) of the motor is dependent on the voltage applied. If 48V = 480rpm, what speed can I expect with 36V and 24V?

 

[rbscebu]

Four hundred eighty RPM rated speed is a fast wind motor designed for speed (28 mph or 45 kph) and does not have adequate torque (only 35 NM max), even with a smaller diameter 20 inch wheel. You need at least 70 NM of torque.

Thirty five NM is too small and will likely use too much amps (easily drain the battery) on startup with risk of overheating

This does not have enough torque for start up and hill climb and can be dangerously fast on the flat or downhill.

You need a motor with low speed winding or a geared hub motor. If you can negotiate with the seller for an exchange, that will be my recommendation.

You also don't need the sprockets, so maybe you can also save money there.

Thank you for the input. I was wondering about what you have raised.

Unfortunately, the purchased hub motor is a fixed deal that cannot be changed. If I cannot use it on the pedicab, I will use it on my 26" mountain bike.

Do you think what I am trying to do with this hub motor on the pedicab is not going to be successful?

 

[Trail Cruiser]

You will need something like the 80 NM geared hub motor used by fat bikes but installed to a 20 inch wheel for even better leverage.

https://www.alibaba.com/product-det...spm=a2700.7724857.normalList.6.214075feQSJoRA

 

[Trail Cruiser]

Thank you for the input. I was wondering about what you have raised.

Unfortunately, the purchased hub motor is a fixed deal that cannot be changed. If I cannot use it on the pedicab, I will use it on my 26" mountain bike.

Do you think what I am trying to do with this hub motor on the pedicab is not going to be successful?

Yes, it can be used on a mountain bike. Make sure you get a good quality lithium battery that will not put your house at risk into burning down. If you go for the lead acid battery, it can be very heavy to carry 4 (12 volt) batteries around.

 

[harryS]

Although one of the pictures shows a pedal assist sensor, another picture doesn't show enough connectors to support pedal assist. Your ad copy doesn't show a pedal assist sensor being shipped either. So no pedal assist as it's known in the ebike world.

Your driver will have to feather the throttle to work in the motor.

I see Pedicabs in Chicago with a big direct drive hub motor in front. It might work. I'd also prefer a geared motor like Mark, but that's a very heavy load for nylon gears. Maybe gearless is best.

 

[Trail Cruiser]

Thank you for the input. I was wondering about what you have raised.

Unfortunately, the purchased hub motor is a fixed deal that cannot be changed. If I cannot use it on the pedicab, I will use it on my 26" mountain bike.

Do you think what I am trying to do with this hub motor on the pedicab is not going to be successful?

You can sell your conversion kit to people in your area and use the money for a geared hub motor and continue your pedicab project.

https://www.alibaba.com/product-det...spm=a2700.7724857.normalList.6.214075feQSJoRA

 

[rbscebu]

This forum is awesome. With your guidance I have saved myself a lot of headaches.

I think it best that I put this pedicab conversion on hold for a while. I will fit the 48V 1000W kit to my 26" MTB first to learn more about electrically powering of a bicycle.

With more experience, I will then be better equipped to attempt the pedicab conversion.

Thank you to all who have graciously provided my with guidance. I will stay active on this forum.