Best Motor/Battery for a Dahon Folder?

[Miles]

battery in a rucksack: thats the way THEY do it here on the pics as well:

I don't have such a large chest to counterbalance the weight, though

4kg is hardly noticeable, in a backpack...

 

[kraeuterbutter]

yes, 4kg are still ok

question is, if you realy need 36V and 10Ah (~4kg of safe Lithium Mangancells)
in an 20" folder
thats some serious km able to drive with that amount of energie

maybe half the capacity is still enough, so why carry more dead weight (into Subway, ...) with you wenn not needed ?
(in my eyes, a folder has to be light as much as possible so you can benefit from carring it around, over staircases, ...)

for the long tours at weekend you can still take a second battery with you and change after half way..

 

[Miles]

If you have a small motor like the Gruber, sure.

Folders should be designed so that, most of the time, they can be easily rolled around on their wheels.

 

[Cyclezee]

battery in a rucksack: thats the way THEY do it here on the pics as well:
http://www.bike-elektro-antrieb.ch/07_aug/Kabel_01_.jpg
http://www.bike-elektro-antrieb.ch/Bilder/Antrieb_47.jpg
http://www.bike-elektro-antrieb.ch/bilder3/dev_3_4.jpg

for 4kg battery-weight:

inthe other Bromton-20"-Folder with Nano-Thread
HERE: http://www.pedelecs.co.uk/forum/electric-bicycles/1673-test.html
he says: up to 9miles range with 36V BOSCH battery 2,6Ah

when you dismantel the BOSCH-Battery-pack and reconfigurate the cells, so they are very FLAT and can huddle against your body, very close to your budy
cell-weight: ~860g

so 1kg should be doable (schrinkrapping or taping the pack and applying some foam plastic between the cells and your back)

i think 1kg flat mounted on your back should realy not be much feelable

Hi Kraeuterbutter, your photo of the lady have given me a couple of ideas only one of which I will put into print.
If I wore a bra (Büstenhalter), I could fit a couple of battery packs inside it, jogger's nipple might be a problem though

John

 

[kraeuterbutter]

well well... here from the same homepage:
http://www.bike-elektro-antrieb.ch/07_aug/Kabel_02_.jpg
Man sieht’s kaum – das Kabel...

(the text under the pictures says: "you can barley see it - the cable")

so: when yours are smaller, there should be plenty of room for storeing batteries )

 

[Cyclezee]

well well... here from the same homepage:
http://www.bike-elektro-antrieb.ch/07_aug/Kabel_02_.jpg
Man sieht’s kaum – das Kabel...

(the text under the pictures says: "you can barley see it - the cable")

so: when yours are smaller, there should be plenty of room for storeing batteries )

Those are best looking pair battery cells I have ever seen But where does the bottom end of the cable go

John

 

[rooel]

I want to fit a motor to a Dahon folding bike and would like some advice and recomendations as to the best motor, battery, controller for this project. I would like to acheive low weight, maximum performance and reasonable cost.QUOTE]


When Dahon produced their now discontinued electric folder, the Roo EL, they chose the Sram Sparc system (rear hub containing 5 speed hub gear, two 100 watt motors, and the controller circuit board - therefore only two external wiring connections: one to the battery, and one to the on/off/battery meter module on the handle bars).

The motor hub needs a rear fork with 135mm drop-out, and having bought some second-hand Roo Els, I found that the motor wheels transferred easily to the Dahon Speed P8 and the Speed Tr, the steel frames of which I find preferable.

As for batteries I would advise switching the original NiMh cells for Lipos, which having 15% higher voltage when fully charged, give a very much zippier performance, aided by their being half the weight of the NiMh.

It is a pure pedelec system (all processing done inside that rear hub) which I find contributes best to fitness improvement, there being no temptation to coast up hill or on the flat.