BH / Dapu M155 freehub, parts and maintenance?

[Joergen8]

I know this is a real old post but is there any chance you could tell me where to locate this free hub?

I really just need the spring clip inside of it because mine was damaged and everything else can just be oil and greased and put back together. I can't get BH to give me an information nor any of the four us suppliers who keep putting me off for months. There are sellers on eBay and Amazon but trying to get the right size is the issue. Thanks in advance if you're still around.

Sorry for the late reply, and sorry about your troubles. I had the suspicion that BH wouldn't be too keen on helping their end users with spare parts, as I've tried contacting their Spain HQ directly about some issues and they've never responded even once. You could try contacting Dapu directly, maybe they could mail you the parts you need: http://www.dapumotors.com/

I still ride my bike daily, but just recently I had a scare with my charger when it stopped charging after a couple minutes and would just shut off. I contated BH directly and they didn't respond. Now I'm communicating with a French retailer to see if they can ship me a charger.

Luckily my friend was able to diagnose the charger and it was just an issue with the two-prong AC cord that sticks into the charger, the female contacts inside the cord had come loose and didn't make proper contact. It was weird that it would still charge for a while though, so maybe arcing or low voltage, or maybe just heat expansion shut it off. Replacing the cord fixed the problem, but I’d still like a second charger so I don’t get stranded in future. The estimate from the retailer is 8 weeks

 

[Joergen8]

Finally approaching an impasse with this motor at around 16 000 km, since the bearing behind the stator circuit/winding board can't be accessed without some destructive force.

Recently this bearing started to make a metallic rubbing or bearing noise, so I opened the motor to discover that the bearing behind the stator winding board, that's inaccessible unless you have the nerve to start modding the motor cable so it fits back out through the axle, possibly has scuffed up bearing races. Luckily there's no play in the bearing, and this bearing does not bear any loads since it just allows the rotor (sun-gear and it's "cup" housing with the permanent magnets) to spin around the stator.

Not worth destroying the motor in the attempt to swap out the bearing, but the motor is getting noisy now when the rotor is spinning (motor is activated).
I added some oil through those holes in the hopes some will get inside the bearing. Not much effect but no harm either hopefully.

 

[fedgez]

Sorry to hear you (and us all) being left helpless with an expensive product one would expect to get decent support for.

Me and KeiKei (another user here on the forum) have been researching the Dapu freehub, and he recons this tool "SuperB TB-1018" is the one to open the cone bearing. I made a similar one from a large socket by welding rods/teeth on it. KeiKei made one by grinding a socket.

He found these videos on generic freehubs:

So the cone bearing is loosened clockwise, a left-handed thread.

My new motor also had a slightly loose free hub shell that rocks/tilts relative to the motor body even when the cassette locknut is tight. It could use opening and retightening, perhaps getting rid of one shim like I did with my first motor (which is tight still after 4500km).

If I did it now, I'd remove the entire free hub assembly by unscrewing the smaller plate from the motor, and assemble the free hub upside down, instead of hunching over a tipped wheel for two hours. This is of course different on the Neo TDCM motor.

Here seems to be a video on the TDCM hub. Too bad the video is poor quality and the guy's hand blocks a lot of it. At least BH tried to show us at some point.

On the TDCM, the outer free hub bearing seems to be a sealed bearing, and he drills into it to make one ball come out of the race, then uses a puller to yank the bearing out. This only fixes the outer bearing though. And these two bearings are just for the free hub/cassette, and bear none of the weight, just allow spinning the cassette in relation to the hub when free wheeling. The actual motor axle bearings would be inside the motor shell. The TDCM free hub seems a tad overbuilt.

I wanted to update this specific version with my experiences.

I have a same/similar look to my motor.
I bought a Super B Shimano Freewheel Body Tool TB-1018
-- That tool fit PERFECTLY into the two groves on the freehubs cone.
--Not realizing it was a reverse thread I turned it counterclockwise and eventually the motor's cover broke free and easily spun open.

My motor was making noise but upon inspection I could not see anything obvious that was the culprit. Once I reassembled (this was a warranty return item so really made no difference and I didn't damage it to remove the cover) I heard the same or similar noise, but since I spread the grease around the nylon gears I also heard more squishy noise for a bit. I believe that one or both of the small bearings on the opposite side of the freehub are bad. The one inside the motor housing would not be too bad to replace. The other one may be a different story.

So 1 the super b shimano tool works
2 in a pinch you could crack the whole motor open using that, but I am not certain how that may or may not damage the freehub---do at your own risk.

I tried to find a wheel hub remover that would work, but they are all too big or too small. I am going to make a 3d print that uses steel pins inserted and see if I can make one strong enough that will last a couple of times. If it breaks after a couple of uses that is likely enough. If it works I can share the design.