I want to build a power-assisted rickshaw bike and SELL MY CAR! Advice, anyone?

[inglese66]

I am an Englishman living and working in Agropoli in the south of Italy. I have a desire - to build a power-assisted rickshaw bike to take my 3 children to school in the mornings and then proceed onto work, a round trip of some 8 - 10 km.

I have joined various forums and entered various discussions, both in Italian and English, with the aim of achieving this goal and I have also created a video appeal for help. The youtube link is:

YouTube - A VIDEO MESSAGE FOR PESWIKI CONTRIBUTORS

So far your Italian cousins

Forum Indipendente Biciclette Elettriche - una bici-rickshaw a pedalata assistita? Siiiiii !

have been very helpful, suggesting a "double freewheel" 250 watt centrally-mounted motor (from, for example, Cyclone). However doubts remain concerning the necessary power of the motor, especially as there are slopes of between 7 and 15%.



We have also discussed the choice between a traditional rickshaw bike and an Indonesian "becak" (front-loading).



I guess what I find so strange is why the rickshaw bike is not a more important means of travel in the western world. Sure, the tourists like a ride around London in the summer, but it seems that it has been excluded as a means of transporting the family, as happens all over Asia.

So what's stopping me from going out and buying one? Well, the price for one thing! Cycles Maximus build beautiful models, with lynch motors and electric assist but they will set you back over £6000 and they are heavy (135 Kg). Others cost even more.

This is basically a bike with a 250 watt motor! I find it difficult to justify such high prices. It would probably be cheaper flying to India, buying a rickshaw bike there and driving it back. Rickshaw bikes will never be taken seriously with prices like that!

I would love a solar powered rickshaw bike (which I imagine would work very well in south Italy) and I would most likely get rid of my car.

What advice can you give me?

 

[tillson]

Don't do it. The children will be bullied if they arrive at school in one of those.

 

[mechaniker]

hi,

3kid´s in step street with 250Watt will be diffcult and only a chaindrive can do this, but forget the cylcone for this, to noise and to weak(it is an inner runner and the controller is also inside what make tempreature problems).
You need a powerfull chaindrive, you must build by yourself i guess like the photo from a stoke monkey

maybe cycle maximus is´nt a cheap product but it is a good product.
You can buy the china copy of this bikes, including shipping and european tax, for around 2000Euro but the quality is very low so it make no sense.

 

[flecc]

Cycles Maximus build beautiful models, with lynch motors and electric assist

This is basically a bike with a 250 watt motor!

That Lynch motor's power as it approaches stall speed rises to well over 4 kilowatts.

A somewhat notional 250 watts.
.

 

[inglese66]

Just started the thread and am already pessimistic...

That Lynch motor's power as it approaches stall speed rises to well over 4 kilowatts.

A somewhat notional 250 watts.
.

Message understood! Just shows how ignorant I am in electric assist matters!

I have no doubt about the quality of the Cycle Maximus bikes as I have read various threads lauding them. I just can't afford one!

Okay! Let's say I in some way avoid the steeper inclines. (possible if I take a different, slightly longer route home) Total load 3 kids, 85-90 kg. Round trip 12 km, is it worth my while continuing this project within the realms of the law (250 watts for Italian law, no weight restriction)?

 

[inglese66]

Aaaah, Italy! If only there wasn't Berlusconi....

Don't do it. The children will be bullied if they arrive at school in one of those.

We are talking about south Italy. Italy is passionate about biking and I am sure that would not happen. I keep abreast of the news from the UK and I know how violent and abusive the school environment has become over there. I live in a town with 22000 inhabitants and have had contact, through teaching, with children at all levels. There is nothing like the same kind of antagonism, I believe mainly due to the very solid Italian family unit. I have lived here almost 20 years and hardly ever see anyone who is drunk or violent.

When English friends talk about their trips to south Italy, they invariably remember how badly people drive (and they do!). When Italians tell me about their trip to the UK, they invariably tell me stories of people throwing up outside pubs and starting fights .......

Hey, if they decide they don't want to ride to school, then fine, my wife is keen to try it out for shopping!

 

[eddieo]

Kids dont stay small for very long.....Before you know it they will be able to ride themselves? and you can all push along individually in an orderly fashion .....with you maybe on an electric cargo bike with all the bags?

 

[inglese66]

Kids dont stay small for very long.....Before you know it they will be able to ride themselves? and you can all push along individually in an orderly fashion .....with you maybe on an electric cargo bike with all the bags?

You should be right, of course, but here on the roads they haven't yet found a translation for the expression "orderly fashion"!

 

[tillson]

We are talking about south Italy. Italy is passionate about biking and I am sure that would not happen. I keep abreast of the news from the UK and I know how violent and abusive the school environment has become over there. I live in a town with 22000 inhabitants and have had contact, through teaching, with children at all levels. There is nothing like the same kind of antagonism, I believe mainly due to the very solid Italian family unit. I have lived here almost 20 years and hardly ever see anyone who is drunk or violent.

When English friends talk about their trips to south Italy, they invariably remember how badly people drive (and they do!). When Italians tell me about their trip to the UK, they invariably tell me stories of people throwing up outside pubs and starting fights .......

Hey, if they decide they don't want to ride to school, then fine, my wife is keen to try it out for shopping!

I'm sure that it will be a great way to get the children to school and they will enjoy travelling in it too. I have family in Novara and am always envious of the gentle family orientated culture in the town.

Good luck with the project.

 

[flecc]

Okay! Let's say I in some way avoid the steeper inclines. (possible if I take a different, slightly longer route home) Total load 3 kids, 85-90 kg. Round trip 12 km, is it worth my while continuing this project within the realms of the law (250 watts for Italian law, no weight restriction)?

It's important to understand that none of the legal bikes are really 250 watts, that's a notional figure based on a sort of average power. Most mid range e-bikes have maximum powers of around 400/450 watts, some at 500/600 watts, and the most powerful like the eZee bikes can be well over 700 watts.

These are all the gross figures, the battery consumption rate. Up to 25% is typically the efficiency loss in transmission and as heat etc, so the net amount available to drive the bike is typically from 300 to 530 watts.

That's only enough for those hills with a pedicab at very low speeds, here's some calculation results. Assuming that the lightest that you could make a pedicab to carry three and yourself is 70 kilos, the kids weigh 90 kilos and you weigh 80 kilos (guessed), the total for climbing is 240 kilos. Fortunately EU regulations permit this, the UK doesn't.

Now I assume you would want to climb at least at 4 mph brisk walking speed, roll resistance needing 30 watts additional. I'm also assuming that the motor gearing is set to provide the optimum climb speed* at 4 mph, which infers a maximum motor assist speed of about 8 mph.

For a 7% hill the power needed is 330 watts.

For a 8% hill the power needed is 370 watts.

For a 11% hill the power needed is 500 watts.

For a 15% hill the power needed is 660 watts.

For a 16% hill the power needed is 680 watts.

Deducting the maximum net power of the motor at 4 mph from each of those figures leaves the amount you would have to provide by pedalling.

* The optimum climb speed occurs when the rise in power with motor revs is reaching maximum just as the maximum torque starts to decline. This is typically about half way up the rev range on the brushless motors that we use.

The calculations are linear. If you wanted to climb at twice the speed and geared the motor accordingly for optimum climb speed at 8 mph, all the power figures required would double. Weight calculations are also linear.

An example of motor gearing. A legal Heinzmann motor for a 26" wheel has it's optimum climb speed at 8 mph. To make it suitable for your pedicab, it would need to be in a 14" front wheel to halve that climb speed. That's not practical of course.

However, they make a lower geared one for climbing that in a 26" wheel has a maximum speed of 11.5 mph and optimum climb speed of about 5.7 mph. If that motor was put into a 20" front wheel, it would make the optimum climb speed around 4.4 mph and provide about 400 watts at that speed. The rest would have to come from you, a bit tough on the 15 and 16% hills but ok on the others.

N.B. At 4.4 mph you have to increase those power needed numbers by 10%. i.e. The 680 watts for the 16% hill becomes 748 watts. Using the Heinzmann motor I mention would leave you with about 350 watts to provide, well beyond the capability of the average rider to sustain for more than a few seconds. If quite a fit cyclist, think in terms of 250 watts for a few minutes. If you've come in the top 30 in the Tour de France, double that for a few minutes short climb.
.

 

[inglese66]

@ flecc

Thanks for such a detailed reply.

But I guess you are talking purely about the motor's power. What about mine? How many watts would I add pedaling?

I want to pedal - I need to pedal!

 

[flecc]

@ flecc

Thanks for such a detailed reply.

But I guess you are talking purely about the motor's power. What about mine? How many watts would I add pedaling?

I want to pedal - I need to pedal!

I'd just added a couple of paragraphs by editing which gives an example of that, which you probably didn't see.

Anything your chosen motor can't provide, you have to of course.
.

 

[CheKmx]

Bakfiets.nl - Models - Bakfiets | Cargobike | Transport bike | Cargo trike | Work bike

I think the Dutch do use this sort of thing. Could you combine a cargo bike and a tow a long so that one of the children added some small input?

 

[Deleted member 4366]

To me, if you want to keep within the legal limit, the only way yo do it is like Frank says with a motor that drives the crank. Unfortunately, I've never seen a decent crank drive kit, but it isn't too difficult to build your own. All you need is a 250w geared front hub motor - like the Bafang - and put a sprocket on where the disc brake fits; then put a chain-wheel pedal on the opposite side to the normal chain-wheel and then mount the motor on appropriate self-made brackets. This is basically how the Stoke Monkey that Frank mentions works. Here's a motor that I've converted ready for a similar project:

This motor can provide about 600w even though it's rated at 250, so according to Flecc's calculations, it should be OK

 

[mechaniker]

To me, if you want to keep within the legal limit, the only way yo do it is like Frank says with a motor that drives the crank. Unfortunately, I've never seen a decent crank drive kit, but it isn't too difficult to build your own. All you need is a 250w geared front hub motor - like the Bafang - and put a sprocket on where the disc brake fits; then put a chain-wheel pedal on the opposite side to the normal chain-wheel and then mount the motor on appropriate self-made brackets. This is basically how the Stoke Monkey that Frank mentions works. Here's a motor that I've converted ready for a similar project:

hi d8veh,

good work with the swxk but you can do it better with a other way working clutch inside the swxk (1picture). Then you dont need to fix a freewheel on the left side and have more choisses for the sprocket and then you also can fix a freewheel crank so you receive double freewheel (2picture)
or you take a specialmade ebikemotor for (it 3picture)

regards
frank

 

[mechaniker]

i forgot the 3picture, now here we go

 

[Deleted member 4366]

You're right (as always!). I might make another solution in the future like you suggest. First, I want to do it with the lowest cost solution. I used an external freewheel on the motor so that the effort to pedal without electric assist will be a bit less, and it was an easy way to fit a sprocket with the bits that I had lying around. I only need to make some brackets to hold the motor in the frame and it's finished, but I'm working on other projects at the moment. Did I unstand correctly that you're developing a kit for a hub motor to drive the crank?

 

[mechaniker]

... Did I unstand correctly that you're developing a kit for a hub motor to drive the crank?

yes i made and sell the Bafang swxk for crankdrive with turned clutch check the photo from one customer what he made with this motor in a cannondale.
I think this a solution for the rikshaw,
but use the Bafang swxk better with Hallsensor because the working is better as the sensorless motor. Also better use a motor what is made for 30" wheel with only 145rpm , then you must not reduce the rpm so much and the torque is higher as on faster motors

and the other motor is also my own production, but i think it is not good to make commercial for my motors in this thread, please check my website and there we can talk further by e-mail.

Here we should help inglese66 for to find a solution for his problem;-)

regards
frank

 

[inglese66]

hi d8veh,

good work with the swxk but you can do it better with a other way working clutch inside the swxk (1picture). Then you dont need to fix a freewheel on the left side and have more choisses for the sprocket and then you also can fix a freewheel crank so you receive double freewheel (2picture)
or you take a specialmade ebikemotor for (it 3picture)

regards
frank

So if I have understood correctly, based on flecc's calculations of how many watts are required for say an 11% hill based on load, bike weight, rider weight (closer to 70 kg actually ), a 250 watt motor, correctly positioned, could be of sufficient assistance to be worth installing?

I have a picture of a cyclone double freewheel motor - this is what you are talking about, right? ( I use cyclone only as an example - my aim is to be efficient, reliable and affordable - asking too much?)

 

[inglese66]

yes i made and sell the Bafang swxk for crankdrive with turned clutch check the photo from one customer what he made with this motor in a cannondale.
I think this a solution for the rikshaw ........

Here we should help inglese66 for to find a solution for his problem;-)

regards
frank

Thanks a lot - it's very appreciated!

I've just posted but it looks exactly the same set up to me, so now the only thing to do is decide on the style of the rickshaw (traditional or front-loader). Would I be right in saying the double freewheel motor would be more efficient and easier to install on the front-loader? My worry is the steering!