Trying to find supplier for rear hub +colour display

Benjahmin

Esteemed Pedelecer
Nov 10, 2014
1,866
1,259
66
West Wales
This is the problem with aliexpress, ebay etc. They don't really know or care what it is they're selling - they just want to sell it.
Try looking at BMS battery, Woosh bikes or Yosepower (I'm sure others will be suggested) at least they are e-bike specific.
 

nelf

Finding my (electric) wheels
Apr 2, 2021
18
0
Northumberland
It looks OK, but they sem to be a bit confused about the motor's RPM. They say 470 rpm (35 mph), which would be too fast to be efficient, then they say 38-40km/h, which would be 313 rpm in a 26" wheel.
I'll see what arrives, likely just a bad description. :D


This is the problem with aliexpress, ebay etc. They don't really know or care what it is they're selling - they just want to sell it.
Try looking at BMS battery, Woosh bikes or Yosepower (I'm sure others will be suggested) at least they are e-bike specific.
None of them seem to have colour displays/USB charging and Woosh didn't have stock for my kit that was recommended so I just decided to ham it and go with aliexpress.

---

Now for choosing the battery - Any recommendations from em3ev?

I suppose I just need to buy based on the Whrs that I want?

 

vfr400

Esteemed Pedelecer
Jun 12, 2011
8,709
3,458
Basildon
I'll see what arrives, likely just a bad description. :D




None of them seem to have colour displays/USB charging and Woosh didn't have stock for my kit that was recommended so I just decided to ham it and go with aliexpress.

---

Now for choosing the battery - Any recommendations from em3ev?

I suppose I just need to buy based on the Whrs that I want?

I'd find out first. If it is 470 rpm, it'll be useless.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
8,709
3,458
Basildon
Sent them a message but doubt they will say which one it is.

I can't find a different supplier that ticks the boxes so may end up ordering it anyway.
Don't think that it's going to go 35 mph because it has a 470 rpm motor. If that's what it is, it's for a 20" wheel. In a big wheel, it won't have the torque nor efficiency to be any use at normal speeds, and you need about 1250w of output power to reach 35 mph whatever motor you have, which means around 1800w from the battery. that translates to 50 amps at 36v or 37 amps at 48v. The motor would burn if you put anywhere near that sort of power through it.
 

nelf

Finding my (electric) wheels
Apr 2, 2021
18
0
Northumberland
Don't think that it's going to go 35 mph because it has a 470 rpm motor. If that's what it is, it's for a 20" wheel. In a big wheel, it won't have the torque nor efficiency to be any use at normal speeds, and you need about 1250w of output power to reach 35 mph whatever motor you have, which means around 1800w from the battery. that translates to 50 amps at 36v or 37 amps at 48v. The motor would burn if you put anywhere near that sort of power through it.
I asked them via chat why the motor isn't on Bafangs website, they replied with this link of a 'different kit'.


Looks like it's this motor: https://bafang-e.com/en/oem-area/components/component/motor/fm-g020250350d/ ?

It looks like they have just created that listing 2 days before I asked about it (google cached version from 26 Apr), if you go to their profile and sort by new it's the first one listed

So if I order it and it's not what they listed I should be able to get my money back - and if it works out, then all is good. o_O

Would prefer to get a kit from a more reputable aliexpress supplier but cannot find one and no one has recommended any..
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
8,709
3,458
Basildon
Yup it's dodgy - do you where I can buy a better kit on aliexpress?
I always buy my stuff from BMSBattery, Elifebike, Topbikekit, Greenbike kit and places like that, but you have to face the facts that it's impossible to send anything back so you have to be very careful that you get your order right. The shipping costs now make their kits a bit dearer than the Ebay ones, but at least you can choose the components you want.
 
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nelf

Finding my (electric) wheels
Apr 2, 2021
18
0
Northumberland
I always buy my stuff from BMSBattery, Elifebike, Topbikekit, Greenbike kit and places like that, but you have to face the facts that it's impossible to send anything back so you have to be very careful that you get your order right. The shipping costs now make their kits a bit dearer than the Ebay ones, but at least you can choose the components you want.
Shipping is definitely a lot worse now that most of the EU won't send stuff to the UK.

What do you think about this kit? The 48V750W geared

 

vfr400

Esteemed Pedelecer
Jun 12, 2011
8,709
3,458
Basildon
In principle, the geared motors should be OK. I don't know this seller. The reviews look a bit suspect, but they might have been translated from Russian to english by a Chinese person, so possibly OK. They offer options and add-ons, but I don't see a system for selecting them, i.e. How do you choose the colour display?

The controllers are listed as 36v/48v. Both the 250w and 350w motors are 270 rpm, but it says that the 350w one makes 33% more torque. That's impossible if they both have a 14A controller and run at the same voltage, so it might be that the 250w kit is for 36v and the 350w one for 48v. Speed depends on voltage, so when it says 270 rpm (20 mph), is that at 36v or 48v? RPM is meaningless without saying the voltage.

Before you order, make sure that you understand the battery requirements. you can use just about any battery at 14A. The 500w kit would require a premium battery with a high discharge rate and the others need the best batteries. Avoid the gearless motors unless you know about how they perform and their battery requirements.

Only the 250w kit is legal.
 

nelf

Finding my (electric) wheels
Apr 2, 2021
18
0
Northumberland
In principle, the geared motors should be OK. I don't know this seller. The reviews look a bit suspect, but they might have been translated from Russian to english by a Chinese person, so possibly OK. They offer options and add-ons, but I don't see a system for selecting them, i.e. How do you choose the colour display?

The controllers are listed as 36v/48v. Both the 250w and 350w motors are 270 rpm, but it says that the 350w one makes 33% more torque. That's impossible if they both have a 14A controller and run at the same voltage, so it might be that the 250w kit is for 36v and the 350w one for 48v. Speed depends on voltage, so when it says 270 rpm (20 mph), is that at 36v or 48v? RPM is meaningless without saying the voltage.

Before you order, make sure that you understand the battery requirements. you can use just about any battery at 14A. The 500w kit would require a premium battery with a high discharge rate and the others need the best batteries. Avoid the gearless motors unless you know about how they perform and their battery requirements.

Only the 250w kit is legal.
Thanks for the response!

Aliexpress has an auto-translate for reviews that are posted in a different language - When ordering I can select which motor, display and wheel size on the main page but for add-ons you send them a message and they will add it to your order and send a request for additional payment separately from the main bill I believe, seems to work quite well from what i've heard.

I think (and hope) you're correct with it being a 48v and they just suck at clarifying descriptions.

I'll be asking them a couple more questions via messages before ordering but right now they are on a national holiday until 6th May.