Newb Project for Foldable Ebike - Advice needed

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Nikfx   100 µW

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Newb Project for Foldable Ebike - Advice needed

Post by Nikfx » Feb 11 2019 6:57pm

Hi Guys,

I've been doing a bit of searching around and research to see what is accessible to me and would like some advice on what you guys would think is appropriate for my bike.

Main purpose of this bike is mainly for commuting to around the city. I am based in Auckland, New Zealand and in the city there tends to be alot of hills.

1) The bike:
I'm not to sure on the exact model but its an oyama folding bike . Hopefully the pics help a bit more.
https://ibb.co/6070vbr

Rims 20"
8 Speed
With Front Derailer (not sure if that will be issue)
Chain Ring ( Front 52T and then there are additional rings)

2) Purpose
Commute within the city and able to handle hills some of which tend to be fairly steep.

3) Kits I've been looking at and Interested in

I've been looking into two options mainly
Mid Drive Kit - BAFANG BBSHD 1000W - https://lunacycle.com/bafang-bbshd-1000w-middrive-kit/

Hub Motor Kit - Mac Motor - https://lunacycle.com/mac-motor-asi-hig ... e-hub-kit/
( Not sure to do rear or front)

Open to suggestions and advise.

4) Battery

Batteries I have been looking at are around the 52v to 48v range.

Budget wise ideally i would like to be under $1500 NZD but willing to bump up depending on requirements.

Any advice or suggestions would be greatly appreciated as this is my first attempt at building an E-bike.


Thanks

docw009   100 kW

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Re: Newb Project for Foldable Ebike - Advice needed

Post by docw009 » Feb 11 2019 11:30pm

If you're looking at Luna, why not consider their folder, based on a Mosso bike.
https://lunacycle.com/luna-folding-ebike/

Per the video attached to the above. At 15 mph, over 25 miles w/o pedaling on a 52V Luna Mini. Crazy top speed over 30 mph.

I think the BBS02 is enough power for a 20" wheel and will certainly spin the cranks faster than you can pedal. The same will apply to a MAC motor. I would not put a MAC on the front forks because of the risk of breaking them.

Batteries are always a challenge to locate on a folder. I have two conversion and have the same Luna 52V6AH mini used to power the Luna bike, plus a custom 10S3P 36V9AH pack, and some 36V 10S4P hoverboard packs. These fit under_the_seat bags I found, but the rubber straps on those bags have all broke, so I've got them zip tied. As a fallback, I also can put battery bags on the racks.

I was not looking for speed or climbing ability so I chose Q100H hub motors. These are geared 12:1, so they have some climbing ability. This is one of the bigger "hills" we have encountered. Sanibel Island Causeway bridge. No problem.
Image

In conclusion, you probably will do fine with the BBS02. The MAC is more than enough.

Nikfx   100 µW

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Re: Newb Project for Foldable Ebike - Advice needed

Post by Nikfx » Feb 12 2019 1:52am

Hi docw009,

Thanks for the response, watching that video and checking out that bike it definitely looks suitable for what I want for my bike and it has given me some ideas on what I can do.

The main reason I haven't considered the luna folding bike is that I kinda want to get my hands dirty and try build one from scratch and also I'm not to sure how shipping the bike to New Zealand will be in terms of costs and duty, and if its even possible to ship with the battery.

The main things I am looking to get from Lunacycle is mainly just the conversion kit and would have to source or build my own battery due to issues with shipping batteries from overseas.

I will defiantly look into the BBS02 for my build as I am leaning more towards a mid drive.

Thanks again for the response you have defiantly given me some things to think about.

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Re: Newb Project for Foldable Ebike - Advice needed

Post by LeftieBiker » Feb 12 2019 2:05am

You definitely don't want a hubmotor - or even two of them - because of their lack of power at high loads at low speeds. The mid-drive means losing the front derailleur, but you shouldn't need it. Make sure you gear the bike what most people would consider too low, because even a mid-drive will be working hard on long steep hills. You can always coast down them for speed! Also because of the hills you definitely want disk brakes - probably hydraulic disk brakes.

Nikfx   100 µW

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Re: Newb Project for Foldable Ebike - Advice needed

Post by Nikfx » Feb 12 2019 6:18pm

Hi LeftieBiker,

Thanks for the response.

Yeah I think you are right the mid drive does seem like a more suitable option.
In regards to losing the front derailleur that would also mean losing the additional chain rings and going to a single aye ?
And if I was to do that what size chain ring would be appropriate ?

I'm also wondering is there any work around that I can do in order to use the derailleur and multiple chain rings with the mid drive or is that just not possible? I did see a forum link where a guy did manage to do that but I'm not sure how much trouble that would be. Link: https://endless-sphere.com/forums/viewt ... 3&start=25

And also I'm not to sure in regards to this comment "Make sure you gear the bike what most people would consider too low" what I would need to do with the bike if i were to remove the front derailleur and try this method.

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Re: Newb Project for Foldable Ebike - Advice needed

Post by LeftieBiker » Feb 13 2019 6:33am

By "gear it lower" I mean use a smaller front sprocket. I'm not an expert on mid drives, but someone should be able to tell you how many teeth you want, after you give the rear teeth count. Yes, you'd be losing the current front sprocket - I think - unless there is in fact a workaround. You'd probably be looking at a top assisted speed of about 15MPH if you geared it low enough to take the steepest, longest hill.

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Re: Newb Project for Foldable Ebike - Advice needed

Post by docw009 » Feb 15 2019 6:24pm

Luna sells the BBS02 with 44T, 48T, and 52T sprockets. I think they had the 46T when I bought mine to use on a 26" bike.

On my 20" folder, a 46T in front, 14T in back (a 46:14T combo) would limit me to around 14 mph with legs spinning furiously. I actually have 48T-11T, which is allows 18 mph. My wife's folder is 52T-11T will go 20 mph with the same cadence. These are hub motors, but I think the numbers translate to hub drives. You get a .74X reduction going from a 26" to 20" wheel, so 52T on a folder is like 40T on a big bike. You don't want to get too small on a folder, if you plan to still pedal it.

" Make sure you gear the bike what most people would consider too low, because even a mid-drive will be working hard on long steep hills."

This is true for bike riders who refuse to touch the shift levers. I live with someone like that. Just remember to treat your motor nice and shift up for hills. My gal gets away with not shifting because she's 130 pounds. Also, it's a hub drive with 12:1 gears.

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Re: Newb Project for Foldable Ebike - Advice needed

Post by amberwolf » Feb 15 2019 10:50pm

FWIW, a middrive doesn't have to lose *any* gears--just that the commercial ones tend to replace the whole BB stuff with the drive, and generally are so wide they make having shiftable front gears impractical for various reasons, depending on the specific bike and drive.


If you have the motor drive the *left* side of the BB, like the Stokemonkey, you can keep all your gears.

The potential problem with that type of system is that you're forced to pedal whenever the motor runs. Not normally a problem, but during the learning process you might get some calf-barking if your feet come off the cranks under motor power. ;)

Nikfx   100 µW

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Re: Newb Project for Foldable Ebike - Advice needed

Post by Nikfx » Feb 16 2019 6:52pm

Hey Guys

One thing I just kinda noticed with my bike is that the bike seat pole comes all the way down which may make it not possible to install a mid drive. And only solution might be a hub drive.


https://ibb.co/K76JCnk

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Re: Newb Project for Foldable Ebike - Advice needed

Post by markz » Feb 16 2019 8:20pm

What a dilemma to have, so when its folded that seat goes all the way down, past the bottom bracket.

Is there anyway you could cut the seat tube so when its in the right riding position, you have an inch or two for the clamp to hold it.

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Re: Newb Project for Foldable Ebike - Advice needed

Post by amberwolf » Feb 16 2019 10:10pm

You don't want to cut the post like that. If it doesn't have enough sticking down into the seattube, it'll just snap the clamp end off the tube from the cantilevered weight on the seat. Might not happen immediately, but when it does you'd be sitting on it and probably hitting a bump or pothole at that moment (which increases the load on it).

Splat.

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Re: Newb Project for Foldable Ebike - Advice needed

Post by markz » Feb 16 2019 10:49pm

Not used to folders, but two inches past the seat clamp/top of the seat tube is plenty, no?
Ah I see, the folders dilemma for adults.... a long ass seat post. Yeah sux!

Nikfx   100 µW

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Re: Newb Project for Foldable Ebike - Advice needed

Post by Nikfx » Feb 17 2019 2:40am

I could reduce the pole but ideally thats something I wouldn't want to do as the main purpose for the seat pole to be that long is when you fold the bike its one of the supports to keep the bike up right, which make the bike easier to be able to tuck under my desk at work. Otherwise I would have to leave the bike on the side on the ground which is fine but I'd rather keep it as is for now and compromise on the motor for now and be a bit more practical with what I have.

In the future after I've successfully converted this bike and seen how it goes then I will be more careful with selecting a donor bike for conversion but for the mean time I'll be happy to work with what I have an see what I can do.

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Re: Newb Project for Foldable Ebike - Advice needed

Post by docw009 » Feb 17 2019 10:34am

If it's going to be the MAC motor, I notice that kit appears to have no pedal assist. PAS is not really much of a concern at Luna. Not many people are pedaling at 30 mph.It's a feature I want though. There are no brake cutoiffs either in the pictures. If your throttle fails, they're needed, especially with a fast bike. Yu could always change controllers, but you're paying for their unit already and they seem to made it easy to connect.

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Re: Newb Project for Foldable Ebike - Advice needed

Post by Nikfx » Feb 18 2019 12:58am

Hey docw009,

The MAC motor is just one of the options I was considering as I saw a nice review on it and looked fairly easy to setup but I haven't done much research on what hub motor to go for, for this bike as I had my mind set on a mid drive.

So any recommendations/advice on kits and motors would be greatly appreciated.

Thanks

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