BBSHD : what is this grinding?

C

CanCD

100 µW
Joined
Sep 12, 2018
Messages
9
Thanks for checking this out ..
I have 1000km on the motor. I'm using a 52 volt 11.6AH Panasonic cell battery . Recently it's started making a noise constantly. I took the side off of it and liberally greased the large steel gear and the smaller gear. No change. I uploaded two videos, so you can hear it. One video is unloaded and the other is loaded. I haven't found another video that replicates the sound.
Thanks for helping.
https://youtu.be/UqE2SdA8fN0
https://youtu.be/ETHZotbH_3o
 
Listened to your videos and my guess is possible the nylon gear inside. Mine just started screaming at me yesterday, opened it up and the main driveshaft from the motor sheared off. Out of the blue no previous noise. Parts are available from Luna but there customer service is lacking in response. Had my drive for 5 months and had a defective charger, controller and now this. Of course their out of stock so I had to purchase a "Bare Bones" motor to get the correct size I needed. Good luck on your issue.
 
Wow that's brutal . Sorry to hear. I thought Luna's CS was supposed to be pretty good ? I spent $180 at lectriccycles and my part hasn't shown up ( 2 days late after I paid $40 express overnight shipping ) and they haven't returned either of my emails. Frustrating.
Would you be able to send me some pictures of your drive opened up and the gear sheared ? Was it just the nylon gear you replaced or was drive shaft damaged as well ? If you aren't able to upload or PM them, please email them: dylanparker3@hotmail.com
Thanks
 
Are you guys running the motors within spec (apart from the 52V thing, that is)? 30A nominal?
 
CanCD said:
Yeah I am.
Click to expand...

Well, boo. I had hoped that the BBSHD would be reliable when run at its design power. One of the installs I've done has had problems with one of the clutches, also at normal spec power (haven't seen it, so I don't know what exactly is the matter).

So far, my BBSHD and the others I've installed have been without notable issues. One of my co-workers accidentally yanked his wheel sensor cable and had to replace his controller, after which the thing has been troublesome.

Please keep us posted as you diagnose and correct the problem.
 
So today that noise has just disappeared. The noise started , 20km later I greased the gears, noise continued. Kept riding , 20km after greasing the noise has stopped.
I expected it to stop immediately after greasing and when it didn't I thought it may need to be worked in to the gears more thoroughly. A long shot I know. Now after 20km post greasing the noise has stopped. I'm not sure if grease has transferred to another part within the motor. I don't know the motor at all or have a schematic so it's hard for me to say. If anyone knows if that's possible or has any other ideas, please chime in. It's a little unnerving to me when mechanical problems appear to fix themselves. In the past I would've been happy, but now I'm apprehensive.
Thanks guys.
 
Here is a pic of the driveshaft that sheared off right where it leaves the motor. All the bearings are fine, every other piece is good even the nylon gear which is supposed to be the weak link. So I ordered the bare bones motor and got the response from the tech that I need to make sure I open up the new drive unit and regrease up everything because Bafang is not very good at doing that. Crap now I need to order new gaskets just incase I damage the existing ones when I open the unit up. As soon as they get replacement motor only section in my size (73-100mm) for 2 bills and a couple of gaskets I will rebuild unit back up and keep for a spare, which I'm sure I will need in the future.
Looks like I gotta resize pics to post. might take a bit.
 
You shouldn't need any gaskets afaik, there's a rubber kinda seal built into the cover for the final drive (under the chain ring), just make sure it's clean (and it's mating surface) and be careful not to over tighten the little screws that hold it down as it's pretty easy to crack the cover. You're not really doing major disassembly here, just crank arm, chain ring and the plastic cover I mentioned above.

That's the side that really needs greasing, the primary reduction (nylon helical gear) seems reasonably well lubed on every one that I've seen.

As for why the shaft sheared off in the first place, make sure your chain ring isn't bent. Assuming you mean the actual output shaft that has the chain ring flange on it.
 
I disagree, I definitely had a gasket that tears incredibly easy when I separated those parts. I hope yours is a newer motor and they upgraded that piece. Good news is I made the gasket so if you don't want to order it / not in stock , you can make them yourself. Keep the template.
 
hey CanCD, did you open the side of the Motor with the nylon gear in it, to check that? i had even worse grinding noise, and the problem was the nylon gear (at first), it was totally peanutbutter. its not that hard to change that, i ordered my replacement from luna.
But on the same time the nylon gear stripped, i had a Hallsensor Error (Errorcode 08). now im trying to fix that...
If your problem with the Noise gets worse, i would check the Nylon gear, its an easy fix.
The gaskets i also destoyed, but made a new one with a bit of silicone.

Cheerio
 
Good call, thanks. I had planned on doing that when the noise stopped. When your nylon gear was stripped , did you also notice a lack of power along with the noise ?
Thanks for replying.
 
1000's miles on 3qty bbshd's without any hiccups.

one unit did begin to make similar noise and went away - never cracked it open. never came back - has bit more side to side play of spindle than other 2 units but otherwise working normally.

bbshd is 1000w continuous power rating. pas levels 8 & 9 will deliver more than that and may be particularly damaging if/when using 'hot rod" programming.

my experience stock bafang programming tends to rollback power to 1000W max continuous when using pas levels 8 & 9 for extended period of time. hot rod programming does not. keep those pas under 7.

very easy to demand more from bbshd units than they're deigned to continuously deliver/dissipate.
 
Okay good info. I have stock programming but I do usually have it in PAS 9 . I didn't expect any damage to come from that.
 
Have you retightened the two bottom bracket nuts?
That's been the only noise for me.
 
CanCD said:
Okay good info. I have stock programming but I do usually have it in PAS 9 . I didn't expect any damage to come from that.
Click to expand...

recommend display with watt/amp meter or insert an inline to verify but most pas 7 usually keeps things around 1000W continuous. depends how long, ambient temps and workload but 8 & 9 can push things a little too much imo. pas 7 will insure solid bbshd longevity. short bursts only 8 & 9.

commute here nearly 1000 miles per month running bbshd's. very reliable but replace chains roughly every 1000 miles to minimize damage to cogs. simple wear gauge will confirm when chain should be replaced. cheap chain $12-$15.
 
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