Electrify my cheap folding bike

[marras]

Hi guys, I've a cheap 20" folding bike, a queridoo ql (see picture), aluminum frame, vbrakes 13kg 6speed... some pretty common I rided a lot for intermodal use (3km bike+ metro+ 2km). I need to electrify it because I prefer do it instead of spending 350€ of metro annual subscription, because I changed the university and now is "only" 14km from home. I tried for a week to go with my bike, but 14km with some good hill make me sweaty, so I need some motor to help me! First I thought to buy a xiaomi qicyle or a fiido d1 bike, but probably invest in some good kit is a better idea, just to be more flexible, also because I quite like that bike. So in this forum I saw a lot of user bought from yosepower, ciclotek and pandabikes, and the cheapest kit (with battery) is the 250W with 36v samsung 10ah battery one from pandabikes. Is that a good deal for about 420€ with included shipping in italy? I read that the motor is 4:1 geared, so it should be able to help me to make up to 10% hill without much effort? please help me!
thank you

 

[harrys]

That's not a bad price. It cost me about $550 USD to electrify my folders with Q100H motor, LCD display, 20A sine wave controller, custom made 30 cell (Samsung GA) 36V10.2AH battery, 20" rim, and nice Saphim Strong spokes. I spoked the wheel myself. I could have bought a complete low cost import e-folder for a little more though.

This is my wife's bike. Range is 50km at 20km/hour on that battery. We have no big hills where we live, but I think pedal assist in the smaller gears plus the smaller 20" wheel should climb a steeper hill.

 

[marras]

Thats a nice work. Finally I bought the kit... but not from pandabikes, because by mail they told me that the torque il 25NM, probably underpowered for the place I live. So i bought from ciclotek 500w kit for 570€, with 22A controller and 11ah 36v panasonic battery. It has a 52NM of torque, but I took a front hub one, because I cause less mountage problems. I hope to mount the battery on the rack. What do you think? No throttle of course, I want to use only with pas at max 30kmh.

 

[marras]

This is my ended first build. What do you think? After 700km it works flawlessy with 500w front hub motor, and 40km of range with 3 level assist, and 36v 11ah (the site advertise Panasonic cells), it's unbelieveble the power this think has on max assist level. Btw, some people told me that is unsafe to use a so powerful motor on the front, even if it's made of steel, but for now no problem, I've checked some times and nothing really changed. What do you think aboht that? I need a torque arm, or I can keep using like this?

 

[wheeliepete]

Bike looks good, front motor and rack battery gives good balance of weight. For what they cost, it is always a good idea to fit a TA or 2, esp. on a large front motor. It will be OK until the axle spins in the dropouts and trashes your motor cable, then you will wish you had spent the extra 25 euros.

 

[Nealh]

Steel forks should be ok, however if possible it is worth fitting a torque arm if you can anchor it securely as mentioned better safe then sorry in the vent of the axle spinning in the drop outs.

 

[marras]

Yeah the weight is pretty balanced, I can go up some stairs without much problems (of course I've to carry 21kg, but doable for some stairs in the metro). Even the folding is not affected at all.
Ok so only one TA would be ok? Is fine if I buy on aliexpress (or others place which sell in Italy)?

 

[harrys]

Looks nice! With your steel fork, I would feel confident with one set of torque arms, but two are better.

 

[Nealh]

Yours forks look ideal for accepting a direct torque arm fixing and using the mudguard stay eyelets to anchor/bolt the T/A to.

 

[marras]

This is my fork after almost 1000km. The fit is identical, as I Remember, with the first time I installed the motor, nothing changed really. Btw I want to install 1 torque arm, but you sugested a direct torque arm, is it compatible with my fork?

 

[wheeliepete]

Might be a angle of the photo, but they do look a little stretched. These are the type of TA I like to use, but this is a 14mm one and I think you will need 12mm. Measure your axle diameter to be sure.

https://www.ebay.co.uk/itm/Torque-Arm-for-e-bike-Heavy-Duty-Stainless-Steel-14x10mm-electric-bikes-ebikes/153308800037?epid=2215529196&hash=item23b1eaa425:g:i6kAAOSwMD5a4sMX:rk:2:pf:1&frcectupt=true

You could use the jubilee clip type and drill it in line with your mudguard eyelet.

 

[Nealh]

The type of TA wheeliepete has linked to is ideal, for a direct fix to an eyelet see if the first piece that slides on to the axle can be fitted in a way that you can utilise an eyelet if not then use will need the second part.
For a one piece TA I make my own ensuring a tight/ snug fit over the axle then shape the remaining oversize metal before drilling a hole to line up with what is available nearby on the frame drop out.

 

[Benjahmin]

+1 for thosw torque arms, I have two bikes with them on and they've never moved. Also they are highly adaptable, might take a while to puzzle it out but you can generally get them to fit to the lug.

 

[wheeliepete]

Seems to be a total lack of these 12mm TA available at the moment, lots selling cheap, thin 14mm versions as "universal"
Could explain the price of this one.

https://www.bikeswift.com/products/torque-arm

 

[marcusvictoria]

Hi, great conversion. I got a cheap 250w 36v byocycles folder with 20in wheels like yours. Mine will do 15mph on pedal assist what's the 500w like for top speed?

 

[marcusvictoria]

I am thinking of a 750w motor.

 

[marras]

It depend by the gear ratio you have. In my case, with 52 on front and 14 in the rear, with 20 inch wheel I can easily do 32/33kmh without much effort. Indeed when I am on flat, I lower the assist to feel a bit more resistece on the pedal, just to keep the speed. I think more than 500w are esagerated, 750w really could be used only on throttle, I don't see the point of a so big pedal assist. 500w are already too much for pas, but I enjoy it anyway

 

[marcusvictoria]

Well, my 2014 byocycle does have a throttle, so could be could.

 

[BG bicycle]

Very nice conversion. Torque arms are mandatory if are going to go any speed and those potholes.

My 20” folder is currently off the road the seat stem collar split and I discovered the frame be magnesium alloy.

6000km+ since June 2018, a crack was expected although surprised happened around the seat stem.

 

[tommie]

Very nice conversion. Torque arms are mandatory if are going to go any speed and those potholes.

My 20” folder is currently off the road the seat stem collar split and I discovered the frame be magnesium alloy.

6000km+ since June 2018, a crack was expected although surprised happened around the seat stem. View attachment 28761

That looks a substantial motor in the back wheel, what is it?
I have a 20" folder as well but the motor could be better.