BH Emotion 29er, motor advice needed please

[Backin5]

Hi chaps, long time no speak - hope everybody has been well.

Long story short, one of my BH Emotion bikes has a fubar'ed hub motor. A couple of years ago I was getting on well with the UK distributor, who was based in Stoke, but they seem to have now vanished? I cannot find who distributes BH in the UK these days, and I've posted this here for a bit of help before I attempt to contact Spain.

The bike is a 29er, and is well out of warranty.

This is the motor:










It looks like a Dapu unit to me. I suspect a collapsed bearing, but have not stripped it yet. Electrically, it doesn't function, and there is a lot of drag when spinning it manually.

My questions are, where can I get spare Dapu parts from if it is the bearing that has collapsed? And what should be my next move - strip it down and inspect? These bikes are known to suffer from bearing issues, my Neo Xtrem had one done under warranty.

Many thanks in anticipation of any assistance.

 

[Nealh]

Yes its a Dapu RD, generally support from BH doesn't appear to be very good. If you suspect a bearing then you need to open it and if it is a sealed bearing there should be a number stamped on it. The bearing in all probability will be a generic one available on Ebay or an engineering outlet/supplier.
Your main problem is it is not working so is the motor wire damaged, you will certainly need to open it to check for any issues.
An easier option maybe is to replace it with a Q128H.

 

[Deleted member 4366]

It's a cassette motor, so a Bafang CST would make a good substitute. I think Ciclotek are the only seller in the EU I've seen recently at a reasonable price:

http://www.ciclotekstore.eu/b2c/producto/2201238/2/bpm-motor

or you can get them from Chinese suppliers:

https://www.aliexpress.com/wholesale?ltype=wholesale&d=y&origin=y&isViewCP=y&catId=0&initiative_id=SB_20170502120113&SearchText=Bafang+CST+motor&blanktest=0&tc=af

There's also the Q128C from BMSBattery or the Bafang SWX02C available from various sources.

Woosh have the smaller, slightly less powerful MXUS cassette motors, which might be OK if you're not hopelessly over-weight.

 

[Nealh]

I did count 9 gears but had it in my head that it was freewheel hub .
I find the Q128C doesn't deliver the power like the bafang cst so being in any gear doesn't work as well. It prefers to be in a low gear to spin the hub from a stand still or from a slower speed. But once you master it, it delivers good torque/acceleration and the 201 rpm winding is good for 21 mph @ 36v if you have the legs for it or have a flat calm day or tail wind. Climbing wise it is good with a lcd/controller set up with 5 assist levels using current control though again you need to select lower gears to spin it up.
Advantages are smaller stealthier hub and its lighter.

 

[Woosh]

there is always some trade-off somewhere.

 

[Emo Rider]

Where are you located?

 

[Backin5]

Many thanks for your replys guys, they are very appreciated.

I have been busy at work, and have only just come back to looking at this yesterday. I wanted to strip the motor down to try and work out what is wrong with it, but have had no luck with cracking the casing. I'm left with this, which I think requires a special tool?




I've tried drifting it out, and bodging a tool together, but with no sucess. I'm probably better just buying another unit off the shelf, most likely a Bafang CST as advised.

I'm put off fitting a replacement unit though, as relacing the spokes seems a dark art?

I am in Derby, Emo.

 

[Backin5]

Just a quick question please before I order this:

http://www.ciclotekstore.eu/b2c/producto/2201238/2/bpm-motor

Do we think this would work on with the existing controller on my Neo 29er? I see no reason why not, but 300 euros is not a small sum.

 

[Backin5]

Although, I have to say I quite fancy one of these:
http://www.ciclotekstore.eu/b2c/producto/9822033/2/nitro-e-bike-motor-kit-48v-without-battery-

I had a Neo Nitro a couple of years back, which was a real barn stormer. My mrs left the back garage door open however, and it got stolen one night. I keep my batteries in the house however, so I do have a Neo 48v battery sat around. I have tried it on my 36 volt Neo bikes, and felt a slight difference.

I don't know if my 29er has the control system to deal with my above linked motor though? How would I test that? Put a meter over the output pins to my buggered hub motor?

And then there's the trade off with reduced range, and really the no no to me of routinely using it on the public highway. I did carefully take my Nitro out from time to time, but frankly it was too fast, and just ended up confusing other road users. A real joy to ride though on the right quiet cyclepath, with all that power, able to sit at 45 kph. I carefully upset many a MAMIL, and I think my hill climb Strava records still stand...

 

[Backin5]

Hi guys, well my 500w Bafang CST arrived today from Spain. Unfortuntely I've had limited success, and would really appreciate any advice.

I've swapped the cassette, tyre, inner tube and brake disc from the old assembly to the new. The connector seems identical. I can get it to power up in the BH 'push assist mode', which is for when you are dismounted and pushing. By pressing the + key on the display, it gives a little 5 kph assist.

However, it either flashes error, or gives spasmodic assist when actually cycling. The main clue I have is that the speedo is not functioning correctly, giving a reading of no more that 5 kph, even though I am making 20 kph with patchy assist.

This is obviously really dissapointing, and quite frustrating, as I don't really know what I'm doing. Can anybody please help?

Jayson

 

[topographer]

Looks like no one's helping you. Maybe you should shout more loudly.

 

[Backin5]

Yes, I'm stuck now, sadly. I've been away on holiday for just over a week, and used a back up bike for the Mrs, with 20 wheels, which wasn't ideal.

I'm thinking the torque sensor and control system on the BH may not be happy with the CST. I suppose I will strip the control system down further, and meter the voltage arriving at the motor when under load.

I'm not sure how the BH works out how fast it is going, but I seem to remember a thread a few years ago on ES, where they were trying to trick the BH into thinking it was going more slowly that it was. I seem to recall they had no success.

I think I could just about rip all the control system off the Xtreme, and fit an off the shelf compatible control system, but I really like the way the BH feeds in power by using it's torque sensor.

I'm assuming there is some kind of hall sensor in the OEM Dapu motor, which works differently in the replacement Bafang. The Bafang looks a beefier unit, and could make a good replacement, if only I could figure out how to get it running.

As always, any help would be most appreciated.

Jayson

 

[Deleted member 4366]

A couple of things I can think of. Does your motor have a speed sensor in it? There's no mention of one in the listing AFAICS. That would mean that you have to splice one in to the white wire inside the controller where the wires separate out of the harness. You can use any sensor cut off an old cycle computer. One wire goes to the white, the other to ground. If that diesn't work the 2nd wire goes to any 5v. I've seen them both ways.

The torque sensor shouldn't care what motor you have.

The other thing is whether you've pushed the motor connector in all the way to the guide-line.