Struggling with BMSBATTERY motors

[d8veh]

If you look on the disc side after removing all the washers etc, you'll see the bearing. The first washer must be small enough that it doesn't touch both the inner and outer parts of the bearing otherwise you get rubbing. If that doesn't solve it. Take the motor out and hold the axle in a vice while you test the motor. If the noise goes away, it's something you've done with washers/spacers.

The S12P is indeed sensorless. It'll still drive those two motors perfectly. Just leave the halls disconnected.

It's difficult to say without hearing the noise, but a faulty phase or hall connection can make the motor make rubbing noises. Try both controllers to see if the rubbing noise goes away. I'd be very surprised if there's anything wrong with your motor.

16 (12) means 16" wheel code 12. It must be fast for a 16" wheel. I've recently become more confused about code numbers. I thought I had it, but I have a 48v code 10, which I run at 36v. It does an easy 25 mph. Code 10 should be 315 rpm at 48v, so I would have expected less at 36v. Therefore the code number must be independent of voltage, so code 12 will do 250 rpm at 36v and 333 rpm at 48v.

 

[tronne]

Hi again, after 5 months and 1,200 km this is my experience:

I had to fix the brakes several times, they weren't adapted for this speed and use.
The gears from the engine are broken, 19$ + shipment + 2h to change it

The rest very nice, more than the speed I'm going it would be too risky for my life I always go full, I don't care so much about battery life, I like to go always high speed haha
Also, I still didn't find a hill impossible to my bike, very nice.

The fan charger is very noisy, I should have been bought a better one.

I think I've said the battery rack from bmsbattery is rubbish so I spent some $ in a good one, a not articulated one.

After these months I have to admit that I've used the bike always as a motorbike (I work with suit, and it would't be a good idea to sweat) and thinking about changing the motor to a non ungeared one, I think the best part of the geared is the weight and having free wheel when is off, but who cares about that if I always use it as a motorbike? Also, 1,2k and having the engine broken it isn't what I was expecting, maybe I was unlucky? maybe the geares are rubbish? not sure.

I'm sure that following this topic will help a lot of people, I was missing this from other posts (to know the end of the story)

 

[jslabonte]

Thank you for the closure Tronne.
I was indeed following this topic, and I'm glad to know how it ended.
As you said, bmsbattery kit lacks long term usage experience like yours.
It's always interesting to read others evolution.

Keep it safe!

 

[d8veh]

That's interesting that your Bafang CST motor's gears were damaged when running with 48v. Did the motor over-heat?

I've been running mine with 36v, which makes the motor run much cooler, especially when climbing. No problems so far after about 2 years and 1500 miles.

 

[LowkeeRider]

I finished my built and put in 300 km so far commuting to work. I did not need to go the two wheel drive route as was plant. I am feather weight. One motor is powerful enough to assist me up those hills doing 35kph. It will run out of steam at 40kph on the flat probably because the Headway battery does not have a high C rating. Still I am happy at that speed.

 

[d8veh]

What was the cause of your rubbing noise?

The headway batteries have a very high C rating, so won't limit your speed in any way. Some of the LCD displays only display up to 40km/h or that's the highest you can set the speed limit. My calculation says that your motor will assist to about 50 km/h, but 40km/h would be about the maximum speed on the flat with no pedalling.

 

[LowkeeRider]

Once I installed the motor in the bike, I don't have that rubbing noise anymore. That rubbing noise happened during testing, it was on a stand and was not bolted down.

It's reassuring to hear that headways are good batteries. The controller is a 35amp Ku123. I am going to find a long stretch of flat road to test the top speed.

 

[tronne]

d8veh it just happened in flat, no overheat.. wierd.
1) So now I'm planning to buy the gears (I think these ones for the CST 36v motor) and thinking about buying a direct drive hub motor using the same configuration.

2) Also I broke a spoke, but not sure if mine are 12G or 13G, and of course bmsbattery are not answering my different emails.

3) What would be your recommendation?
If I'm not wrong we have the Q11 48v 1k W 370 rpm, the Q128 48v 500W 201 rpm, the Q128H 48v 800W 201 and 328 rpm, the Q128 36v 500W and 201 328 rpm and the Q128H 36v 800W 201 and 328 rpm.
I've read that the Q128 is not very good.. not sure.
So I'd like to have the same torque and speed as with the CST 36v 500W with 48v battery and the S12s controller (more or less 45km/h)
Probalby I'll have to overvolt a 36v motor with 201rpm to get some extra speed vs 48v 328 rpm

4) Any of them has cassette?

5) All of them are compatible with the S12s controller, I understand they have also the same wire connector to the wheel, (the 9pin waterproof connector)

Thanks!

 

[d8veh]

I don't know what connector is on the Q11, but I think all the rest have the 9-pin connector. If not they have a long wire that goes all the way to the controller. The Q128 has smaller gears than the 500W CST, so I can't see that motor as an improvement. Also, I'd be surprised if they can give the torque of the 500W CST.

Your spoke is 13g.

Only the 500W CST has the cassette spline. For any of the others, you'll have to get a DNP free-wheel and suffer inprecise gear-changing.

 

[tronne]

Thanks! So you are saying that Q128 is geared, not direct hub?
What would be your recommendation for an ungeared motor from the ones above?

 

[d8veh]

The Q128 motor is geared. I don't use direct drive motors because they're too heavy, so I can't recommend one. The Q11 is the only one that BMSB sell.

 

[tronne]

After some time, I write here again to write my experiences..
During 2 years I've bought geared and not geared motors, and I'll go for the geared ones, the axis of the bike was suffering too much with the non geared, first because it's heavier and second because the power given to the axis is way stronger than the geared motors. Ah, and also because there's no way to take out the wheel completely without having to cut the wires.
During this time I've bought a snow bike, and this is my new Project, I decided this because if I run at 45km/h is to much for a normal bike Wheel, that's why I need a wider one, no matter if it's heavier.
I'm spanish and is difficult to buy these bikes without having to spend a lot of money even for the cheapest one, apparently our goverment doesn't like chinese bikes, so I bought it in NY and brought it in the plane (free with British Airways or Iberia)
I'm not sure if it's possible to adapt a rear wheel motor to the snow bike wheel, not sure if someone did it already. If not, I'll go for a mid motor (also better for the bike axis, I broke it twice.)
If someone is in doubt about mid motors, I think is the best idea (but I haven't tried them)
Hope this helps I would have appreciated a post like this 2 years ago.

 

[d8veh]

You can get special hub-motors for wide wheels now. Check your bottom bracket width before buying a middle motor. The bikes with wide wheels usually also have wide BBs.