Christiania Bike conversion

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Arvicola Terrestris   100 W

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Christiania Bike conversion

Post by Arvicola Terrestris » Feb 03 2015 5:13pm

I often gets question about my conversion of my Christiania Bike (cargo trike) into an center motor e-bike. So I've decided to dedicate a thread to Christiania Bike conversions. NOT ONLY MY BIKE, YOURS TOO.

Why Christiania Bike in particular? Because there is a rather large community loving these bike, which until recently all has been built in the Free town of Christiania, Copenhagen, Denmark, a comunity with 2000 souls. A place for Hippies, Cannabis and car-free culture :D and it's still like that, I visit the place once a week :wink:
Attachments
P1040388 800x600.jpg
My Christiania Bike on the island of Bornholm, where these bike are made now. I'm such a fan that I had to visit the factory.
Christiania cargo trike, Bafang bbs02 750W, 48v, 16s2p LiFePO4 30Ah, 50kg
Grace mxII Urban S, 2. gen. Bosch 350W, 36v, Bosch Powerpack 400 11Ah, 23kg
Trek T420+, BionX PL250 HT, 250W, SRAM 3 speed IGH, 36v LiMn 9,6Ah, 20kg

U.S. Costomary Unit = SI Equivalent:
Length: in. = 25.40mm - ft = 0.3048m - mi = 1.609km
Mass: oz = 28.35g - lb = 0.4536kg
Pressure: psi = 6.895kPa (MPa = N/mm^2)
Velocity: mph = 1.609km/h
Volume: gal = 3.785l

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Arvicola Terrestris   100 W

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Re: Christiania Bike conversion

Post by Arvicola Terrestris » Feb 03 2015 5:42pm

I got these questions in a PM:
Here are some questions that I have:
1: I gather you had to bend the frame. Is that true of all Christianias, or only certain models?
2: Is there insufficient clearance to mount underneath the frame?
3: How does one go about bending the frame?
4: Are there less intrusive options that you have heard of?
5: Any other modifications that would also be necessary in order to complete the conversion?
My conversion is with a Bafang BBS02 750w 48v.

1: If you will fit the Bafang BBS02 to an Christiania Bike I only know of one model and that is the one with the large single frame tube. There are older model with double frame tubes which can't be used. Also it has to be the steel model, not aluminium, because you need to weld.

2: yes, see picture number two

3: Most people would need help from a blacksmith, and it will only take him one hour to make this operation.
But if you do it yourself the use a hammer and blow torch to make the dent.
Attachments
Christianiacykel (1) red.jpg
Frame before modifications
IMG_20150103_155140 red.jpg
Here the dent is seen. It is NOT possible to mount the motor under the frame.
IMG_20150103_155140 red.jpg (241.14 KiB) Viewed 3058 times
IMG_20140404_172658 red.jpg
The weldings on the cross member are seen and the heat from the dent under the motor
IMG_20140404_172658 red.jpg (242.97 KiB) Viewed 3058 times
Christiania cargo trike, Bafang bbs02 750W, 48v, 16s2p LiFePO4 30Ah, 50kg
Grace mxII Urban S, 2. gen. Bosch 350W, 36v, Bosch Powerpack 400 11Ah, 23kg
Trek T420+, BionX PL250 HT, 250W, SRAM 3 speed IGH, 36v LiMn 9,6Ah, 20kg

U.S. Costomary Unit = SI Equivalent:
Length: in. = 25.40mm - ft = 0.3048m - mi = 1.609km
Mass: oz = 28.35g - lb = 0.4536kg
Pressure: psi = 6.895kPa (MPa = N/mm^2)
Velocity: mph = 1.609km/h
Volume: gal = 3.785l

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Arvicola Terrestris   100 W

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Re: Christiania Bike conversion

Post by Arvicola Terrestris » Feb 03 2015 6:23pm

Here are some questions that I have:
1: I gather you had to bend the frame. Is that true of all Christianias, or only certain models?
2: Is there insufficient clearance to mount underneath the frame?
3: How does one go about bending the frame?
4: Are there less intrusive options that you have heard of?
5: Any other modifications that would also be necessary in order to complete the conversion?
4: Not on the Christiania cargo trike model, but they make a two wheel model which I'm sure you can mount a center motor without the need of welding and other very hot techniques.

5: Depending on the the power of your motor, you could upgrade the front brakes to hydraulics, it makes a big difference when going 35km/h. It is also a good idea to place the battery in the front of the cargo box it stabilizes the bike, you can test it with a kid, first in the back of the cargo box and then in the front = big differers in handling. A mirror is also nice to have.
Christiania cargo trike, Bafang bbs02 750W, 48v, 16s2p LiFePO4 30Ah, 50kg
Grace mxII Urban S, 2. gen. Bosch 350W, 36v, Bosch Powerpack 400 11Ah, 23kg
Trek T420+, BionX PL250 HT, 250W, SRAM 3 speed IGH, 36v LiMn 9,6Ah, 20kg

U.S. Costomary Unit = SI Equivalent:
Length: in. = 25.40mm - ft = 0.3048m - mi = 1.609km
Mass: oz = 28.35g - lb = 0.4536kg
Pressure: psi = 6.895kPa (MPa = N/mm^2)
Velocity: mph = 1.609km/h
Volume: gal = 3.785l

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Samd   1.21 GW

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Re: Christiania Bike conversion

Post by Samd » Feb 04 2015 12:52am

I suggest a smaller chainring to take the torque off the motor. Your clutch and controller will love you for it in the long term.
http://ballaratebikes.com/

ImageImageImage
"Knowledge is knowing that a tomato is a fruit. Wisdom is knowing that a 165mm rear shock can't deliver 220mm of rear swingarm travel." - Oprah Winfrey.

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Arvicola Terrestris   100 W

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Re: Christiania Bike conversion

Post by Arvicola Terrestris » Feb 04 2015 1:28am

Samd wrote:I suggest a smaller chainring to take the torque off the motor. Your clutch and controller will love you for it in the long term.
Depends on how big the rear chainring is :wink:

The gear ratio is 2.1:1, which is right in the blink, T46 in front and T22 at the rear. I have a NuVinci in the rear wheel and they specify a maximum gearing of 2:1.
The Nuvinci Autoshifter is set at approx. 75 rpm (pedal arm).
Highest motor eff. is at 85 rpm (pedal arm) and
highest motor torque is at 65 rpm (pedal arm).
Attachments
IMG_20140306_131235 red.jpg
The gearing calculation
Motor Characteristic curve 3.jpg
Motor Characteristics
Christiania cargo trike, Bafang bbs02 750W, 48v, 16s2p LiFePO4 30Ah, 50kg
Grace mxII Urban S, 2. gen. Bosch 350W, 36v, Bosch Powerpack 400 11Ah, 23kg
Trek T420+, BionX PL250 HT, 250W, SRAM 3 speed IGH, 36v LiMn 9,6Ah, 20kg

U.S. Costomary Unit = SI Equivalent:
Length: in. = 25.40mm - ft = 0.3048m - mi = 1.609km
Mass: oz = 28.35g - lb = 0.4536kg
Pressure: psi = 6.895kPa (MPa = N/mm^2)
Velocity: mph = 1.609km/h
Volume: gal = 3.785l

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Re: Christiania Bike conversion

Post by whollycow » Feb 04 2015 11:23am

No concerns over the structural integrity of the bike after modifying the frame like that?

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Arvicola Terrestris   100 W

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Re: Christiania Bike conversion

Post by Arvicola Terrestris » Feb 04 2015 2:48pm

whollycow wrote:No concerns over the structural integrity of the bike after modifying the frame like that?
No

The mechanic properties of the cross member is the same after the modification, only concern is the strength of the welds, because its difficult to weld galvanized steel (galvanized inside also).

The modification to the large frame tube, the dent, is in a place were the stress is not so large. In an effort to explain were the critical forces are applied to the frame, I have made a very simple schematic static calculation of the frame. (VERY SIMPLE)
Statisk beregning af stel.jpg
The area from G to H (GH) is were the dent is, the load in this area is aprox. 60-70% of the load on the saddle. (which can be 3x larger then your own weight when you hit a pot hole). The saddle is at point J, the rear wheel at I. The large frame tube is simulated as an beam A-D-H-E.

I'm not saying that load in this area is negligible, but it is not the most stressed part of the frame. And remember that we aren't removing anything from the frame, just relocate it with a very large hammer :)

If the frame should start to break up because of material fatigue, then steel is breaking slowly, while aluminium snaps.
Christiania cargo trike, Bafang bbs02 750W, 48v, 16s2p LiFePO4 30Ah, 50kg
Grace mxII Urban S, 2. gen. Bosch 350W, 36v, Bosch Powerpack 400 11Ah, 23kg
Trek T420+, BionX PL250 HT, 250W, SRAM 3 speed IGH, 36v LiMn 9,6Ah, 20kg

U.S. Costomary Unit = SI Equivalent:
Length: in. = 25.40mm - ft = 0.3048m - mi = 1.609km
Mass: oz = 28.35g - lb = 0.4536kg
Pressure: psi = 6.895kPa (MPa = N/mm^2)
Velocity: mph = 1.609km/h
Volume: gal = 3.785l

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Re: Christiania Bike conversion

Post by whollycow » Feb 05 2015 1:26pm

Did you have the NuVinci on the bike by the time the motor was installed? I have the 7 gear IGH (Schimano? Can't recall at the moment). I know the motor can present difficulties with shifting, but I suspect with a motor on it we won't need to shift as often. We mostly need the motor for the couple of hills standing between us and civilization. We don't expect to ride it too hard.

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Arvicola Terrestris   100 W

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Re: Christiania Bike conversion

Post by Arvicola Terrestris » Feb 06 2015 7:07pm

whollycow wrote:Did you have the NuVinci on the bike by the time the motor was installed? I have the 7 gear IGH (Schimano? Can't recall at the moment). I know the motor can present difficulties with shifting, but I suspect with a motor on it we won't need to shift as often. We mostly need the motor for the couple of hills standing between us and civilization. We don't expect to ride it too hard.
The NuVinci was part of the conversion I did. Before the bike had a Sram hub system with integrated 5 gear IGH. The NuVinci is a major upgrade. You won't need more then 5 gears. Depending on what motor wattage you choose, but with a 750 watt motor there is no hill that will stop you.
Christiania cargo trike, Bafang bbs02 750W, 48v, 16s2p LiFePO4 30Ah, 50kg
Grace mxII Urban S, 2. gen. Bosch 350W, 36v, Bosch Powerpack 400 11Ah, 23kg
Trek T420+, BionX PL250 HT, 250W, SRAM 3 speed IGH, 36v LiMn 9,6Ah, 20kg

U.S. Costomary Unit = SI Equivalent:
Length: in. = 25.40mm - ft = 0.3048m - mi = 1.609km
Mass: oz = 28.35g - lb = 0.4536kg
Pressure: psi = 6.895kPa (MPa = N/mm^2)
Velocity: mph = 1.609km/h
Volume: gal = 3.785l

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Arvicola Terrestris   100 W

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Re: Christiania Bike conversion

Post by Arvicola Terrestris » Feb 07 2015 6:20am

I thought about writing about the Christiania bike in more general terms, and then found this excellent English written history on the homepage of the Christiania Bikes company

So here it is, from the companys mouth:
The first Christiania Bikes 1984

Christiania is an area in Copenhagen which used to host the Navy. When the military moved out, the barracks were left empty for years; in 1971 young people moved in. The I/S Christiania Smedie (=Smithy) was founded in 1978. Christiania chose from the beginning to be a car-free area. This motivated its inhabitants to think of other means of transport. At first robust bicycle trailers were developed by originally using old bed frames. Later these bicycle trailers were improved and sold all over Denmark. In 1984, the first cargobike was launched. Its ground-breaking feature was that family cycling, including children transport, was made available in a practical and safe way. Children transport has been maintained over the years as the core function of the Christiania Bikes tricycles.

Soon, people outside Christiania noticed the manoeuvrable, sturdy and environmentally friendly cargobikes and in 1990 the Christiania Smedie moved to the island of Bornholm to concentrate on production of tricycles. Our goal was to offer a convenient replacement to the car, and eventually the idea of family tricycle would become a normal means of transportation all over Denmark. Indeed nowadays the family tricycle has become a popular means of transport all over Denmark and in many countries across the world as well.

In Bornholm, we continually refine our products. In 1994, the company was renamed “Christiania Bikes“, and our products bear this world-famous trademark.
annie-boernladcykel_.jpg
Picture from the homepage, should be the founders wife, with her new Christania bike (the first one build). This particular frame design is not used anymore.
annie-boernladcykel_.jpg (244.97 KiB) Viewed 2876 times
Information and picture taken from:
http://www.christianiabikes.com/en/
Christiania cargo trike, Bafang bbs02 750W, 48v, 16s2p LiFePO4 30Ah, 50kg
Grace mxII Urban S, 2. gen. Bosch 350W, 36v, Bosch Powerpack 400 11Ah, 23kg
Trek T420+, BionX PL250 HT, 250W, SRAM 3 speed IGH, 36v LiMn 9,6Ah, 20kg

U.S. Costomary Unit = SI Equivalent:
Length: in. = 25.40mm - ft = 0.3048m - mi = 1.609km
Mass: oz = 28.35g - lb = 0.4536kg
Pressure: psi = 6.895kPa (MPa = N/mm^2)
Velocity: mph = 1.609km/h
Volume: gal = 3.785l

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Re: Christiania Bike conversion

Post by whollycow » Feb 08 2015 3:02pm

So I had been assuming all this time that my frame is steel. I just checked and it is actually aluminum (or at least a magnet didn't stick to it). I'm guessing that means no possibility for making the kinds of modifications we're talking about. Any ideas?

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Arvicola Terrestris   100 W

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Re: Christiania Bike conversion

Post by Arvicola Terrestris » Feb 10 2015 2:34am

whollycow wrote:So I had been assuming all this time that my frame is steel. I just checked and it is actually aluminum (or at least a magnet didn't stick to it). I'm guessing that means no possibility for making the kinds of modifications we're talking about. Any ideas?
I won't recommend doing this Bafang BBSxx conversion if your frame is aluminium.

The most straight forward conversion would then be to lace a hub motor into your 24" rear wheel. 500watt should be great and 1000watt awesome.

A conversion with two hub motors in the front wheels has been done, and working well (with regen!), but it's much more complicated.

So go for a rear wheel direct drive hub with regen. at approx 750w.
Christiania cargo trike, Bafang bbs02 750W, 48v, 16s2p LiFePO4 30Ah, 50kg
Grace mxII Urban S, 2. gen. Bosch 350W, 36v, Bosch Powerpack 400 11Ah, 23kg
Trek T420+, BionX PL250 HT, 250W, SRAM 3 speed IGH, 36v LiMn 9,6Ah, 20kg

U.S. Costomary Unit = SI Equivalent:
Length: in. = 25.40mm - ft = 0.3048m - mi = 1.609km
Mass: oz = 28.35g - lb = 0.4536kg
Pressure: psi = 6.895kPa (MPa = N/mm^2)
Velocity: mph = 1.609km/h
Volume: gal = 3.785l

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Re: Christiania Bike conversion

Post by whollycow » Feb 10 2015 1:59pm

Arvicola Terrestris wrote: The most straight forward conversion would then be to lace a hub motor into your 24" rear wheel. 500watt should be great and 1000watt awesome.
Looks like this is my best option. I was hoping I could keep my IGH but I guess I'll have to make a sacrifice...
Thanks for the help anyway!

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Re: Christiania Bike conversion

Post by Dumsterdave » Mar 05 2017 9:45am

I know this thread is quite old, but I also have the aluminium frame christiania. I wanted to do the bafang mid drive, but i guess it may not be a good idea... My bike currently has an internal geared hub and there is no place to mount an external rear derailer. Ive looked at the christiania bikes that are electric and they all seem to have a different model of dropouts that allows for a derailer to be mounted. What are my options here?
Last edited by Dumsterdave on Mar 12 2017 3:36pm, edited 1 time in total.

Dumsterdave   100 W

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Re: Christiania Bike conversion

Post by Dumsterdave » Mar 05 2017 10:20am

ive found this... https://boxbike.dk/da/elcykel-kit/162-e ... cykel.html
so i know there are mid drives that will fit into that space, but i dont know who makes this kit. Also, i would like to get a bit more powerful motor than the 250/350 36v that they sell

what about the cyclone or mini cyclone that lunacycle sells? Has anyone had any experience mounting these?

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Re: Christiania Bike conversion

Post by 183sunman » Jul 26 2017 12:52pm

Dumsterdave wrote:I know this thread is quite old, but I also have the aluminium frame christiania. I wanted to do the bafang mid drive, but i guess it may not be a good idea... My bike currently has an internal geared hub and there is no place to mount an external rear derailer. Ive looked at the christiania bikes that are electric and they all seem to have a different model of dropouts that allows for a derailer to be mounted. What are my options here?

Hi i make already some conversion Christiania bike , and also in Copenhagen. For you back drop outs (internal gears oryginal) ou can easy use external , also back disc break.

For this you need 1) adapter disc breaks for "not hydraulic-frame" , and 2) Adapter External gears

Zdjęcia

Zdjęcia

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Re: Christiania Bike conversion

Post by pnissen84 » Feb 20 2019 2:01am

I know this thread is quite old.

I did a conversion of an aluminium Christiania bike with the kit from boxbike above (BEWO 36v 350w). I’ve done over 2.000 happy km on the bike, but now the bearings inside the mid drive hub is roasted.
It seems like the bbs02 hub is more reliable, but seems impossible to fit on my bike. I’m therefore looking for alternatives, like the back wheel drive. But don’t know what to go for, dimensions etc.?

Or is there any alternatives on the market I 2019 with a smaller mid drive, that will fit in the fram of a Christiania bike Alu?

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Re: Christiania Bike conversion

Post by Chalo » Feb 20 2019 2:12am

pnissen84 wrote:
Feb 20 2019 2:01am
It seems like the bbs02 hub is more reliable, but seems impossible to fit on my bike.
Why do you think that?
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

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Re: Christiania Bike conversion

Post by Dumsterdave » Feb 20 2019 4:47pm

pnissen84 wrote:
Feb 20 2019 2:01am
I know this thread is quite old.

I did a conversion of an aluminium Christiania bike with the kit from boxbike above (BEWO 36v 350w). I’ve done over 2.000 happy km on the bike, but now the bearings inside the mid drive hub is roasted.
It seems like the bbs02 hub is more reliable, but seems impossible to fit on my bike. I’m therefore looking for alternatives, like the back wheel drive. But don’t know what to go for, dimensions etc.?

Or is there any alternatives on the market I 2019 with a smaller mid drive, that will fit in the fram of a Christiania bike Alu?
I actually ended up getting a bewo from a UK source that was about half the price of boxbike. It's at 4500km and still running strong. Not the most powerful motor, but it does the job

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