Folding E-Bike

[ShlomiMir]

I'm a first time builder, working on making a folding e-bike for my work commute. I will be using this bike as my main means of transportation in the city, parking it in my apartment at night, and occasionally fold it up for longer distance public transport.

I have already purchased a 36v 250w rear install Bafang motor and infineon controller, based on reviews I have read here. I am also going to get some sort of battery, still shopping around.

I am now looking for a good folding bike to finish up the deal. I am looking for something cheap, reliable, with some form of suspension, at least on the back. I would like to keep the wheel size between 20" to 24". I don't need the bike to super tiny when it's folded, but I do need to keep the weight down. Most importantly, I want it to be relatively comfortable in the city going up curbs and down potholes and to hold together for a good few years while doing it.

Does anyone have experience with folding bikes of this variety? It doesn't have to be shiny, it doesn't have to be 2009, it just needs to be good .

Any advice welcome.

 

[morph999]

I was impressed with this one. It's 26" folding bike. I've never seen a 26" folding one before so I favorited it. I think most are like 16" or 20".

http://www.bazookasports.com/navigator-yellow-p-3.html

oh you said 20"
http://www.bazookasports.com/folding-bikes-nautica-x-c-1_5.html

 

[jkt]

Dahon is one of the largest folding bike manufacturers and they offer a wide range of models . Prices range from $200 to over $2000 USD depending on model. I have a 2008 Speed D7 for city commuting and I like it a lot. (www.dahon.com)

Downtube makes decent, value-oriented folders. Several of their models have both front and rear suspension. The quality may be a step down from Dahon. Prices are under $500. (www.downtube.com)

Bike Friday makes high end, performance-oriented folders. Check out the Tikit line for city commuting. Prices are generally $900 and up. (www.bikefriday.com)

Brompton is one of the most famous folding bike makers, based in the U.K. They're known for bikes that fold really compact. Prices are over $1000. (www.brompton.co.uk)

 

[morph999]

hightekbikes.com has some electric fold-ups

http://hightekbikes.com/ebikes.html

 

[jondoh]

I had a dahon d7 with a crystalyte 406, 20 amp controller and
56 v Milwaukee batteries. It was a great bike but then I upgraded
to a revive with a 5303 and sold the folder to get money for the
car conversion. Dahon bikes are solid.

 

[ShlomiMir]

Thanks for the suggestions so far.

From what I am seeing, it seems as if the best option for me is a Dahon Speed, preferably a second hand one in good condition .

However, the part of me that doesn't have to pay bills is intrigued by the Brompton, which seems to be brilliant. However, how on earth would one fit a battery pack on one? There is no place for a rack, etc. Has anyone done an electric conversion of a Brompton? How does it fare?

 

[nathan_jones]

hello ShlomiMir

heres some research for you

these guys make kits in the uk
http://www.nano-motor.co.uk/factsheets/BromptonNanoFactSheet.pdf

factsheet
http://www.nano-motor.co.uk/nanobrompton.php

this guys asks same question as you
http://www.pedelecs.co.uk/forum/electric-bicycles/496-brompton-electric-not.html

newspaper review of the combo
http://www.telegraph.co.uk/motoring/caraccessories/2744318/I-want-to-ride-my-bicycle.html#2

another review
http://www.commutabike.co.uk/

american kit for brompton
http://www.poweridestore.com/Folding-Bike-Kit/Crystalyte-Traveler-Series-Folding-Bike-Conversion-Kit

this is my project which is putting a heinzmann on my brompton
http://endless-sphere.com/forums/viewtopic.php?f=3&t=9032

this is the cheapest (and where i got mine) place to get a rompton in the uk
http://www.gumtree.com/cgi-bin/list_postings.pl?posting_cat=86&search_terms=BROMPTON&min_price=&max_price=
have aholiday/vacation to london and bring a bike back there is no air charges the fold is that small.

If I could do it again id buy one of these http://www.egopt.co.uk/ego_hub_motor_kit_2003.pdf, electric motors and the management of electronics is a process which requires from my experience learning a lot. So start with something that works by people who know.

ps the brompton is a BADASS BIKe!!! the best folding bike ive ever rode! and built to last!! however if your in the states it might be more practical to got to http://www.bikefriday.com/PreOwned

 

[mingonn]

Just a heads up. Most folding 20" bikes run a narrow 70mm front hub which means you will need a rear hub motor or be prepared to so some serious metal work to get the gap to 100mm.

Derek

 

[Starson]

Just a heads up. Most folding 20" bikes run a narrow 70mm front hub which means you will need a rear hub motor or be prepared to so some serious metal work to get the gap to 100mm.

Derek

Hi Derek, this is my first post & i'm a newbie. Apparently the new eTikit under development from Bike Friday will be using this brushless # 209 motor. Wheel sizes 16" - 20" designed for Dahon & Brompton folders, motor has a 75mm dropout, weighs 3.9 kg., and comes in 24 v : 180 w or 36 v : 250 w. Follow this link in UK http://shop.crystalyte-europe.com/product.php?productid=16137

Gary

 

[Drunkskunk]

I'm working on putting together a fold my self. right now I'm still in the info gathering stage, but I've found a few things that may be helpfull.

The older style Dahons had a dual hinge design, with both a top tube, and a down tube. From my limited mech. eng. understanding that should be a stronger, stiffer design. Since you plus a 250 watt motor is doubling the power the bike is designed for, every little bit of extra bracing should help.

20" bikes do have narrower forks, but for a front motor design, I was looking at using BMX forks for the addes striength. Since there is a huge racing market, there are plenty of forks that are both lite and strong out there.

That Clyte 207 looks interesting, and I'm a big fan of Clyte motors, but a geared hub motor would be lighter. I've been looking at Bafang, BMC V1, and eZees, which all have a good reputation, but I may try one of these Cute ( yeah, thats the brand name.. ) motors which weigh under 4 pounds.