Which e bike conversion kit and battery?

[diru78]

I am currently in the process of buying an e-bike kit which I will use to transform an existing bike of my wife to an e-bike which. I am a complete newbie and would love if experienced users here can help me in any way they possibly can. I am an engineer by trade and after watching a couple of videos I think building the bike won’t be much of the problem, however, I am not sure about which kit to use.

She will use the bike few times per year (max 20 days per year), mostly on holidays, in order to be able to cycle with me. I am thinking about bafang motor, either 500w or 750w? What do you recommend? We would mostly use it on hilly rides(where speed doesn’t really matter because I am much slower than any assisted e-bike will be) but I would also like the bike to be able to hold a speed around 22mph (35km/h) on flat sections.

Regarding the battery? What do you suggest? I am from Europe (Germany) so it is either buying the battery from China or European store. I would of course prefer Chinese battery due to low cost, however, I am wondering if you have good experience with any specific Chinese brands and which?

How big should the battery be? 48v 14ah or should I go higher (eg 48v 17ah). Realistically I expect that we will never go out for more then 2-3h (meaning about 60-70km on flat terrain).

All help will be much appreciated!

 

[harryS]

What style of motor? Mid drive Bafang or one of their hub motors?

What about German ebike laws. Are you classified as an S-pedelec if your bike can exceed 25 km/hour. Does that cost money or safety gear?

 

[Al P]

I retrofitted my Mongoose with a 500w 8fun (Bafang) front hub kit, which is great for hard surfaces and easier to install than the others. Comes with a choice of either of two batteries for either down tube or rack mount. The kit is complete and just a bit more for a thumb throttle (recommended). https://www.e-bikerig.com/
The kit is well-made and the service is excellent.

 

[diru78]

What style of motor? Mid drive Bafang or one of their hub motors?

What about German ebike laws. Are you classified as an S-pedelec if your bike can exceed 25 km/hour. Does that cost money or safety gear?

Regarding, mid drive or hub drive I am not sure. What do you suggest? I was thinking about mid drive but if you think hub drive would be better, I am open to the idea. We will ride mostly on paved road, maybe occasionally on gravel but never on any technical off-road paths.
Honestly, speed limit doesn’t bother me since the bike will mostly be used on holidays in Austria and Italy where the speed limits are the same, however, it is not really enforced. Also, I am not talking about driving at insane speeds. We would never need to go above 35km/h which is the speed I can hold on flat sections.

 

[indianajo]

Mid drives can be equpped with torque sensing assist, which is very natural. It feels as if you are stronger than you really are. Cadence pedal assist kicks in abruptly with a fixed speed after 2 magnets are passed, even if you are pedaling backwards. I don't like the feel. Mid drives can climb steep hills in Aust or ITL with the 350- watts the europeans are allowed to have. This is due to the torque multiplication of the sprocket set.
Geared hub drives can climb steep hllls too, due to the internal gearing. Geared hub drives have an internal clutch which allows them to be ridden without power without drag. Only yamaha & shimano mid drives have this feature, which I find important for maintaining heart health at my age (68).
Direct hub drives I would not recommend in Europe. I'm allowed to buy a 1000 W model which powers me up steep hills very cheaply. You are not allowed that many watts in the EU.
A good vendor is important to buying a battery that is not junk. I am familiar only with good reputable vendors in US, canada, & Hong Kong. Another forum, probably in german language, would probably give you better advice.

 

[harryS]

Indianajo, your cadence sensor shouldn't work if pedals are spun backwards. The sensors are designed for that.

Diru78, a middrive kit allows you to keep your rear wheel/sprockets intact, which is good if you happen to own a good internal geared axle hub. However, most do not support a front derailleur. Mid drive also allows the same process you already had for removing the wheels for maintenance. If you used QR skewers, you keep them.

With a hub motor, you need a wrench to remove the nuts and enough mechanical ability to keep sufficient torque on them. Mid drives require users to understand how to shift, as they make use of the gears to allow a smaller motor to do more.

 

[harryS]

The type/style of your wife's bike will dictate the motor, battery placement, and operating speeds. You would have to provide that.

Her preferences need to accounted for too. Is a person who cycles not even twice a month going to be comfortable with 35 km/hour rides?

A number of chinese vendors have warehouses in Germany. PSWpower and Unitpackpower are two chinese vendors that do so, and sell motors/batteries.

 

[tomjasz]

Unitpackpower

Left us out in the cold and didn't honor warranty service. Their fella repairing in German is awful! Terrible communication and left two travel writers stuck with failed batteries and no repair follow up. We ate the total cost including shipping. Yeah, OUCH!

 

[kmccune]

This is rather late I know,I have an ebike cruiser, that has a 750 watt(1050 max) Bafang Hub Motor this thing punches above its weight I never realized a Hub motor would climb this good,I changed the freewheel and going flat out the ( slight downgrade ) it registered a bit over 39 mph ( too fast for me) a geared Bafang should be fine for your conversion, my bike weighs 82# and it is rather hard to pedal unassisted,I usually never go above PAS3 and never use 4 or 5 unless something is ready to chase me on the level 1 0r 0 works great( I pedal,I don't use that thing as a Moped) On my Builds I have actually had good luck using 20 AH wrapped batteries.

 

[Browneye]

EDIT: Nevermind...didn't realize someone had resurrected a dead thread. What we call a 'necro-post'. LOL

My ebike conversion thread here: https://electricbikereview.com/forums/threads/specialized-roll-hub-conversion-q-a.31055/
Have since sold the bike - got her a 'real' one. LOL

The Greenergy people have a reasonably good product, Amazon or AliExpress, or ebay. A 500w Bafang hub with a 10-11ah battery is more than sufficient for what you want. The battery I got with the kit was never a problem, worked great. The only problem currently is the possibility of a long shipping time. Getting anything out of china these days seems like an effort in futility.

 

[kmccune]

Sorry 'bout that, after awhile perhaps these threads need to go away.

 

[stanmiller]

I have Bluenergy/Greenergy Bafang kitted bikes as well. My bikes are equipped with Bafang SWX02 motors. After 3000 miles I had to recently replace the clutch gear assembly on my cargo bike.