BH / Dapu M155 freehub, parts and maintenance?

Joergen8

Active Member
#21
Every manufacturer has to come up with multiple enclosure designs to fit each application and to avoid infringement, so yours is different, but it still might be a Dapu. Could be a Dapu M155 CD for all we know, which is similar to the motor I have. Yours has no threat of balls falling into the motor since you don't have screw holes or openings near the free hub, but the free hub is more expensive to replace, if it was meant to be a throwaway part like traditional free hubs.

BH has done their very best to hide the OEM for sure. It took Dapu 3 months to reply to my previous question, so asking to identify your motor would take a while.
 
#22
Hello Joergen,
I went on the Dapu site and from all the motors that they have, the only designed one they show with the "10-tooth" removal application on the cassette side like mine is their Dapu M155-CD motor.

I sent them an email just now questioning them about that large special 10-tooth socket-type tool needed to remove the faceplate and also the additional info needed about a possible replacement for the Freehub on that motor, hopefully I'll get a prompt reply.

All this sneakiness about servicing these motors/freehubs is a complete joke if you ask me. For a simple part replacement like a Freehub, I suppose they take that as a simple sell for a complete brushless motor for $800 instead, what a joke!

Here's the new 2016 Dapu M155-CD in a polished body but you can clearly see the "10-tooth" tool needed for it. Notice how Dapu describes this motor having an Internal Freewheel, I would like to see what's behind this motor plate for the "internals" of this Dapu M155-CD motor to understand exactly what do they mean in this type of design!

Dapu M155-CD.JPG



.....and here's mine which is a 2014 Dapu model


IMG_2806.JPG
 
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Joergen8

Active Member
#23
The internal free wheel probably refers to the one-way bearing found in these geared hub motors, in either a pawl and ratchet or a clutch/roller design (that Dapu use). It allows the planetary reduction gear to disengage the axle when free wheeling forward. See this video.

 
#24
Same as the main one-way bottom bearing at the output engine geared clutch in a helicopter main rotor shaft. Main rotor engagement on power up, free wheeling rotor spin on power down/power off. Then the Dapu M155-CD like what I have not only has an external cassette free(wheel)hub, but also as they describe on their site having an "internal freewheel (bearing)", makes sense.
 

J.R.

Well-Known Member
#25
@Joergen8 you've really done some amazing work here that transcends the 29'er. I just noticed the updates. Not only detailed, but for me it's just as important it's in English with perfect syntax. Thanks so much, BH owes you a paycheck. Of course they'd prefer that we just throw our "old" models away and purchase new. I break my bike wheels down a couple times a year at tire repair or changes to new or studs. With the 29'er I've stopped shorter than I'd like, but you've detailed some workarounds for the proprietary issues that are all important to us shade-tree mechanics.

Thanks
 

Joergen8

Active Member
#26
Thanks J.R! Glad you found it useful.

edit: Updated the instructions with optional Step 23, should your bolts seize or deform.
 
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#31
How much you charge for rebuilding this?

Also how reliable are these motors? And are the bh controllers pure sine wave controllers ?
 

J.R.

Well-Known Member
#32
How much you charge for rebuilding this?

Also how reliable are these motors? And are the bh controllers pure sine wave controllers ?
Sorry, I don't think anyone in this discussion is in the ebike business. I am not. Just shade tree mechanics.
 

Joergen8

Active Member
#34
how long these motors last before needing a rebuild?
I think the service-life stated in Dapu's documents for this type of motor is 30 000km, and that's probably when you'd have to replace the plastic gears in the planet gear, but they don't sell spares, so you'd have to bin the motor. But 30 000km is pretty decent with no service, and for an e-bike as a whole, where you'd have to replace the battery once or twice already.. and just buying a new bike makes more sense economically (if perhaps not ecologically). Other popular motors like the Bosch system have to be serviced every 3000km or so (replacing some plastic seal near the bb), and it's not easy to do either, which is border line ridiculous for a commuter bike. The Yamaha and Shimano motors are service-free though.
 
#35
I have a BH easy Motion Dapu Motor, never used, for sale in classifieds. Currently laced for a 20”Volt, but could fit any Easy Motion. Also controller and high capacity battery.