Loud Magnum Metro motor

[adcockj]

I have two Magnum 500w hub drive bikes, a Metro and a Peak. The Peak is fine, and the Metro works fine, but it's really loud. On acceleration, when the motor is working the hardest, it sounds normal. However, when just riding along at the "set" speed, the motor makes quite a bit of noise, kind of a twangy rattle. I'm wondering if there's any way to grease it internally some way, or if that's just the way it is...some bikes make more noise than others. Again, it works fine, but it's the loudest bike on the trails (and there are LOTS of ebikes on the multi-use trails where we live). I also have two Treks that I've converted with Bafang BBSHDs, and they're whisper quiet compared to the Metro.
Any ideas?

 

[adcockj]

Yes, it's out of warranty. And I agree that it looks exactly like a Bafang (which the Peak has).

I'm willing to dig into it some. It's my wife's bike, so I'll have to "tread lightly". I'll watch some Youtubes and see what I can come up with. I'd even be willing to just swap it out for another motor/hub assembly. I wonder if a standard Bafang set would work, or if there might be something odd with the Das-Kit set.

 

[indianajo]

I took the cover off my hub motor and took a look. Put some more grease in there, which had worn off the gears to empty space. Not difficult at all. Takes a sharpened screwdrive to get under the cover and start it off when screws are out. Use blue loktite going back on. Your cover might be loose, mine was thumping because of that.

 

[adcockj]

timpo: Did I mention that this is my wife's bike? No upgrades desired...just a quieter ride. I even offered to get her a new bike, but she really loves this bike (I've done things like a comfort seat, a Kinekt seatpost, ergo grips, etc). She only has about 1500 miles on it, so it should be a long time before it needs replaced.

I've looked at some of the YouTubes. It looks like it should be pretty easy to pull it apart and grease the gears...I have some Mobil 28 that I use on my BBSHDs.

Thanx for the responses!

 

[steve marino]

You might be getting a harmonic vibration. That's always a possibility. They can be tricky to track down, but the usual drill is to loosen, then re tighten, every fastener on the bike and see if this helps. I was a Toyota dealership mechanic back in the day, and when the Feds here in the US reduced our highway top speeds to 55, it turned out that several of our models had this between 52 and 57 MPH. No one ever noticed it before because no one drove between those speeds. If the hub motor is not secured correctly, that could cause noise issues too. Again, loosen the retaining nuts on the axle, shift the thing around a little bit, and re tighten and see what happens.

 

[Bungee Sue]

I have two Magnum 500w hub drive bikes, a Metro and a Peak. The Peak is fine, and the Metro works fine, but it's really loud. On acceleration, when the motor is working the hardest, it sounds normal. However, when just riding along at the "set" speed, the motor makes quite a bit of noise, kind of a twangy rattle. I'm wondering if there's any way to grease it internally some way, or if that's just the way it is...some bikes make more noise than others. Again, it works fine, but it's the loudest bike on the trails (and there are LOTS of ebikes on the multi-use trails where we live). I also have two Treks that I've converted with Bafang BBSHDs, and they're whisper quiet compared to the Metro.
Any ideas?

I wonder why they didn't put grease nipples on these hubs. It's easier and safer than opening up anything