Bafang 500W Rear Hub Drive Cassette Size for 10x135 Dropout

richj8990

100 W
Joined
Jan 21, 2020
Messages
277
Hello everyone,

I have the same Bafang 500W Geared Hub Motor on the front, and it's been nice, but it's time to get one for the rear for many reasons I won't elaborate on. Let me give you some tidbits of evidence below about potential issues of trying to put an 11-speed cassette on the hub in a 135mm QR dropout frame. You are free of course to respond with your own experience. I can always do 9-10 speed if I have to but I already have extra 11-speed drivetrain stuff, so...

1. E-Bikeling has direct drive rear hubs that can take a cassette instead of a freewheel, but they say on their site that it's 10-speed max, or the 11th (or 12th) cog will either not fit on their hub spline or it will rub against the frame.

2. Some commenter from another site, who has installed a lot of these on the front and back, said they would recommend a front hub because they can never get the back hub drive installed right. That's a weird comment from someone who has installed them multiple times. I'm wondering if he's using 11-speed and that's the 'installation' issue.

3. I just read a different article saying the geared rear hub drive is great (I'm sure it is), but, unlike Bafang or 8Fun or Greenergia or anyone else, says it can only take a 10-speed cassette max, and just barely. Another thing I 'could' do is take out the 13t cog and make an 11-speed a 10-speed. If it's then a bit too short, put a spacer in the back of the cassette.

4. But the same article from (3) above then went on with a diagram that has me worried... This is online, it could be fake news so to speak, but either the diagram is right or wrong. I'm hoping it's wrong.
Link: https://edrivenet.com/bafang-hub-motor-review/

It said single speeds take up 120mm (plenty of room between 120 and 135 for spacers).
6-speeds (people still use those?) jump to 130mm.
7-speeds 138mm (already more than 135mm).
8-speeds 140mm
9-speeds 142mm

Extrapolating to 10-speed 144mm, 11-speed 146mm, 12-speed 148mm. That can't be correct can it??? I ran an 11-speed cassette in a 135 frame for 3 years and it was fine. But...it was not on a hub motor.

How much more does a geared (not direct) rear hub motor stick out compared with a standard 10x135 or 12x142 hub?

Again, I could take one cog out but if the chart is correct, I'd need to take 2-3 out if they are roughly 4mm each with the spacers. And that's too many to take out and have decent shifting. I also could try to buy a carbon 12x142mm bike with hard plastic axle acceptors and convert that to dropouts (and still have the 142 or even 148 mm spacing) but that's dicey and I would really prefer aluminum dropouts. And as you know aluminum dropouts are only 10x135, end of story because aluminum chainstays can't bend like a carbon chainstay can.

Has anyone here used a Bafang 500W Geared Rear Hub Drive with an 11-speed cassette?
 
You are overthinking this.
All the geared hub motors I have used, (Cutes, MXUS (simular to Ebiking motor, but better), Bafangs, Ezees, etc) have been 132 to 135 m/m overall width w/ 9-sp free whl.s/cassettes.
There are two styles of "500" watt geared hub motors. The "mini" type, which are wider w/ a smaller overall diameter (2 to 3.5 Kg.s), like the SWX series and the "mid" style (around 5 Kg.s) like the BPM, which are thinner w/ a greater overall diameter. In general, the thinner motors are easier to install, which is not the say the mini's are always difficult.
Of the dozen or so Mini's I have installed, only one turned out to be difficult to the point that I gave up and that probably had more to do with the chainstays not being well aligned in the jig when the bike was made.
Whether you are thinking free whl. or cassette, you absolutely need a 11 T sm. gear. Don't even consider anything less. If the overall motor/cassette width ends up several millimeters wider the the drop-out space, it's NBD. The stays can easily be spread (w/ bare hands) to accept the hub/gears. What's important at this stage is to get a flat washer between the cassette and the inside of the drop-out so they won't rub together.
You didn't tell us what motor you have now and what you are considering, but I will tell you what I have now and how it came about. On my mountain bike w/ 26" whl.s, I had a super cheap "Jump" Bafang SWX02 on the frt. that I didn't care for that much.
https://endless-sphere.com/forums/viewtopic.php?f=2&t=110408&p=1673330&hilit=bafang#p1673330
It was a little heavy for what I like on the frt. and was faster that I cared to go (27mph w/ 52V batt.) I bought a rear 11T motor here;
https://hilleater.ca/bafang-swx02-rear-cassette-motor-fast-11-turn-winding-fits-juiced-ccs/
and dropped the motor core into the frt. whl ASM, saving me the trouble of building another whl. Maybe you can do the same.
The end result is my fav. ebike Ive ever built. 24 mph from a small motor, that still climbs fairly well and w/ a 11T/48T gear combo, I can pedal along right up to top speed.
Getting the motor speed range and gearing (including whl. size) well matched is critical with smallish hub motors.
 
I'm planning to go with a rear hub and realize that the dropouts may need to be bent out about .5 cm. A few ways to do this: as per the late Sheldon Brown site you can use a 2x4 wood leveraged between main frame and drop out area. Another way is a hydraulic jack. Or get another bike with wider dropouts. Slight bending should not harm steel, but I can't say for sure about aluminum or carbon type frame. The more width the more gears you can fit.
 
RTLSHIP said:
I'm planning to go with a rear hub and realize that the dropouts may need to be bent out about .5 cm. A few ways to do this: as per the late Sheldon Brown site you can use a 2x4 wood leveraged between main frame and drop out area. Another way is a hydraulic jack. Or get another bike with wider dropouts. Slight bending should not harm steel, but I can't say for sure about aluminum or carbon type frame. The more width the more gears you can fit.

I don't do any bending, but I use a large screw driver, and place it between the freewheel and frame to spread it enough to slide into the dropout. Basically stretching it the width of the washer on that side. The screw driver makes it easier, but I can do it by hand if I need to.
 
Maybe I should try your way. I still have to buy it and see how close it gets. But slight bending should not harm bike. Chain and peddle will be unaffected.
 
RTLSHIP said:
Maybe I should try your way. I still have to buy it and see how close it gets. But slight bending should not harm bike. Chain and peddle will be unaffected.

The way I figure it, in order to permanently bend the stays, you'd need to spread them further than what you want them to end up at. I didn't want to take that chance if I didn't need to. Once you do get the technique down, it's easy. There's some fiddling with the washers just to get the other side partially started, but after that it goes right in with a little help with the screw driver.
 
Yeah, just use a flat screwdriver. I've even used a C-washer for the inside washer (between the inside of the drop-out and the end of the cassette/free wheel), spread them apart and slipped the C-washer in.
 
My rear dropouts are 130mm. The typical rear kit is 135 and a C washer inside makes it more like 140. I have a C washer on inside front hub and they do give added bite onto flats with the torque washer through it. Yet with all that and a torque arm, I had my share of imbalances and spin outs on front hub.
 
By C-washer, I mean a flat steel washer. I never use those built-up cast spacer/washers, they cause more problems than they solve.
 
motomech said:
By C-washer, I mean a flat steel washer. I never use those built-up cast spacer/washers, they cause more problems than they solve.

ok. The C washers I use are open ended like a C shape, about 2 or 3 mm flat. Bought 4 from the real Ebike company. I'm interested in the Yescom 1500 watt kit. It doesn't have PAS or computer screen, but the controller can go sensorless or with hall sensors. And a good price. I currently use spacer washers to cover for damaged thread area.
 
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