BH / Dapu M155 freehub, parts and maintenance?

Joergen8

Active Member
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.
 

Paul Dee

New Member
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
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.

 

Paul Dee

New Member
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
@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
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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Krishna

New Member
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
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
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.
 

hikingdad

New Member
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.
 

lewie

New Member
Hi, I got the motor and controller a few days ago, checked the motor, it worked. Did you also have a battery?

Lew
 

Nico2019

New Member
Hello all!

UPDATE: FREE HUB overhaul. I've now studied how to overhaul the free hub, click here to skip to the updated instructions https://electricbikereview.com/forum/threads/bh-dapu-m155-freehub-parts-and-maintenance.2293/#post-59082

UPDATE2: MOTOR ROTOR and main bearings. Finally pulled out the motor to see the planetary gears.
https://electricbikereview.com/forum/threads/bh-dapu-m155-freehub-parts-and-maintenance.2293/#post-46485

Long story (skip to question below):

I've had my 2015 Evo 29er for about 6 months now, and I've been servicing it myself as I do all my bikes.

I've had no technical problems thus far with over 2200km / 1400mi riding, but yesterday I propped the bike up on the repair stand and started listening to the rear cassette and freehub. It was making a telltale sandy/crunchy noise, and the cassette had some play in it.

Video:

I took off the rear wheel, took off the cassette (lock ring), and the freehub was indeed slightly loose. So I took off the locking nuts on the rear axle, used a special tool to open the cone bearing on the end of the freehub, had the usual explosion of tiny (bearing) balls, cleaned them and the freehub body in turpentine solvent, regreased the bearing grooves and reseated the balls, reassembled the b*tch of a thing after many tries of testing which shim (of various thicknesses) to ditch in order to remove the play in the freehub. Success! No more play and crunchy noises, or the very rare but annoying slip of the freehub ratchet pawls.

Now! Question: the freewheel hub body has no manufacturer details, seems somewhat specific to hub motors. Can one buy these freehubs from somewhere? Freehubs are supposed to be throwaway parts, but you can't buy these from your local bike shop. Seems to me, the lower freehub (bearing) balls are in a groove that is on the Dapu motor frame itself, and if the freehub is not serviced in time, can damage the motor frame itself.

UPDATE: no, we can't buy these. You'll have to overhaul it yourself.

Thanks!
Dear Joergen, I've seen your long, detailed and great pictures as I am looking for a solution with my noise and almost not running with this motor (M155) on my ebike... but it looks that I have it mounted in a different way and I would like if you could add a picture of the wheel mounted on the bike (ready to run). I have the motor model number, CS 3610 M155, printed on the cassette side, not in the brake side..... I have not started to dismantle it, but I guess that either you have the gears on the left side of the bike (??) or my motor is sideways....
I don't know if I've made clear enough... Anyway, thank yu for the fantastic job!!!

Best regards from Barcelona
Nicolas