gmcjetpilot

HELP! Brompton Folding Bike 16" Wheels eBike Conversion
A start up Swytch electric bike kit is coming out with an new kit and have a signup to be notified. I think it will be more than I want to pay. google swytch-ebike-conversion-kit-for-brompton. Their set up is super clean. If they are in the $500-$600 range that is the way to go. However I think it will be $1000.

QUESTION - does anyone know of a good (and cheap relatively speaking) kit or source for parts for a roll your own eBike conversion. I am a capable DIY'er and can buy ala carte and wire things. I have found some kits on eBay and AliExpress for 16" front wheels. I am looking at about $380 (with shipping) and $130 for 36v/10aH battery with BMS. Total about $500.

CRITERIA: - Since it is a folding bike and want to still fold the bike, I will put the battery, controller and display unit all in one bag on the handle bar or head tube. Brompton's and clones have a bracket on head tube, made to mount a bag. I will have to disconnect the hub motor, throttle and PAS pedal assist system sensor. Which leads me to my last question. Do I need a PAS?

QUESTION do you need the pedal-assist system (PAS) sensor on crank. The kits come with it, but can I leave it off? Can't I just use the throttle as needed when pedaling,. Not sure I can fit it on based on type of crank I have? The less wires and connection to disconnect to remove from bike to fold the better.

The last option is do nothing and actually pedal the bike 100% under my power, as bike spirits intended.

Doc_Wui

I prefer both throttle/PAS, but yes, the e-kits for hubmotors do not require the PAS sensor to be attached. To keep in the spirit of a Bromptom don't you need a 74mm dropout?

These guys have them that narrow. I would buy a bare motor and spoke it in the USA. It costs a lot to ship a wheel assembly from China, often more than what the motor costs..
ebike hub motor,front motor,24V/36V/48V motor,200-350W motor,500w motor for electric motor

If you only use throttle, then you don't need the better ebike controllers where the money is spent on a display interface and control of PAS. You just need an on/off switch,and a bike computer. Probably get by for $20 for controller and $10 for a throttle, At least one brake lever switch is advisable in case of throttle runaway (it happens),.

Batteries that fit in a bag are numerous. If they were available, the LiGO 36V battery is expensive, but safe, Probably the best there is, in my opinion, but I don't own them.

https://ebikes.ca/product-info/grin-...batteries.html

There are plenty of 36V packs with more AH that are not so safe. Maybe not safe at all,. Do your research. Those Swytch packs look kind of fun,. Bet they're not cheap.

kayakindude

Swytch has one set up specifically for Brompton and or users of the front mounting bag. They have a new look with a slim battery and 60% off if you do a survey. I think prices are higher now (what isn't). My kits were 500 and they are probably 700 now.

I got this survey email a bit ago- I can follow up with the offering price when they launch.



my controls are directly on the battery, I think the new setup uses a phone app.

gmcjetpilot

Great tips. I did not think of getting just hub motor and rolling my own spoke / rim. Not sure where I would buy rim and spokes. The price is $140 for motor only and $230 for hub motor and rim (for Brompton). $90 I'll buy the assembly. The kits with motor hub and rim are not terribly expensive, but they do sell kits with just the hub motor. I'll have to look at that.

I got the prices from Swytch. Right now they have no product to sell as they are about to release their second round and new design products.. They are a start up company and had an initial product release. Prices are $1249 o $1949 for depending on options. The folding bike option is the $1949 price. Of course. If you sign up as early buyers, you get 50% off, so it $975 + tax and shipping I assume. I can roll my own for $500, but their design is pretty slick. However a grand is too much.

Now that I know price of Swytch, I'm out, They China made Brompton kits. for $350 minus battery are OK,. With 36v 10ah battery $500 total should get it. If I follow your tips I cold shave off a $100 or more. I am going to do some more research, because learning is part of the goal and fun. Thanks again for the great info and to all who responded. This is a great forum.

kayakindude

Pres-sale came out today.

they have that air model that can travel on planes, but it has a fairly short range.

tds101 

Um,...NOPE!!! Better off getting a Bafang kit IMO.