What's a good ebike kit for a 20" folding bike?
Posted by Zegrade@reddit | ebikes | View on Reddit | 12 comments
I ordered this folding bike from alibaba. It's a brompton clone with 20-inch tires. What's a good ebike conversion kit for it? I plan on using this bike for touring around the US along with using buses and trains. I was thinking of a hub motor since it's cheaper than a mid drive. Specifically, the Bafang 48V 500W Rear Hub Motor Kit 20" tires(the whole thing with secondary battery comes out to be $910 which seems a lot in my opinion) But I was wondering if it would be enough to tackle hills or not. Is my selection good, or are there better options?
heyheni@reddit
Hi congratulations on your purchase it's a good touring bike. But unfortunately it's not so good for making it an ebike.
That Bafang hub motor won't work. The Mint T9D uses a narrower non standard 120mm hub spacing for a more compact fold. Standard normal bicycle hub o.l.d is 135mm. So it's 15mm too narrow for standard hub motors.
If you must use a brompton specific front motor. But i wouldn't trust the Mint T9D forks holding up touring thousands of miles through the continent with a motor pulling and braking. Remember the mint t9d is a cheap bike designed for urban commuter use. But maybe it will work just fine?
However there's this extremely expensive german middrive system called Pendix that would work best. https://pendix.com
In any case for your adventure upgrade the gearing for hill climbing. A wheeltop EDS OEX 2 Medium cage electronic derailleur with an 11 speed 11-46t casette will get you over mountains.
I wish you a very successful adventure. And we're happy to hear from you in r/foldingbikes and r/BrompNOTs 👍🏻
MDZPNMD@reddit
Curious to know why you doubt the Mint T9D fork? The T9D is built pretty sturdy besides the rear rack.
To add to this, you can always decide to coldset the rear triangle and put in standard sized hubs while losing only 1-2mm of tire clearance.
heyheni@reddit
Because on my Mint T9C on tour ~400km in the rear hinge bolt broke in the middle of nowhere. Then i was reminded that this is a cheap bike that has it's limitations.
You're the guy who dimpled the rear chain stay for wider tires right?
MDZPNMD@reddit
yeah, the feelings are mutual, always following your posts and good to know.
Rear hinge bolt is goona go into my spare kit
heyheni@reddit
What do you think about this ebike kit? 😃
MDZPNMD@reddit
dunno, looks sketchy, I think the only viable option is cold setting the rear to fit a standard hub size.
If you opt for a Brompton hub motor you won't be able to use the disc brakes and with a middle motor you wont be able to fold it.
heyheni@reddit
good point
Mysterious_Bass6202@reddit
I have just installed one for a friend who doesn't want to b edazzled by complexity. I used a TSDZ750 which is torque driven. That works very well indeed and suits the 20" just fine. Not a speed devil but goes up any hill!
heyheni@reddit
But you cant fold the bike with a Tongsheng tszd. The wheel swings under? That's the problem.
atlasraven@reddit
I wish you great adventures but understand that "good" is highly subjective. What is good for you might be unsuitable for someone else.
Creative-Scratch8588@reddit
How much is it? I sell EBike.
Lordly_Lobster@reddit
I'd probably opt for the 750W Bafang motor for not much more money. You'll never want more and it will handle hills fine.
If you can't find the hub motor you want already built into a 20 inch wheel that fits your bike be sure to budget a couple hundred dollars parts and labor to have it built into a wheel.
$910 seems a little high. JohnnyNerdout.com sells 750W bafang hub motor kits built into a wheel for $450 and a battery would cost another $350. I think if you shop around you can do a little better.