Rear hub motor maintenance

rvehock

Member
Looking to tear into my rear hub motor (350W geared) on my 2015 Leisger CD5, the gears are getting very loud and I think it may be time to crack it open and see what is going on. I have about 3500 miles of use on the bike and it performs very well except for the growling noise that is beginning to radiate from the rear hub motor. I am getting some substantial vibration so I am not sure that I may need to replace the gearset or just need to clean and lubricate the gearset? I would appreciate any comments or suggestions that may help me out with the teardown of the rear hub.

Kind Regards,
Bob
 
Best of luck finding a replacement gearset. I think luna had some for the brand they were selling.
I went into my direct drive unit to discover the source of binding up, but there were no moving parts inside to spring out and get lost. Difinitely work on a clean unobstructed surface to catch any parts that blast out under spring pressure. A little lube may save your unit, but at 3500 miles I suspect a gear motor might have reached life. NGLI #2 grease might be a little thick; I would try lubriplate if you find the lubrication needs updating.
 
Best of luck finding a replacement gearset. I think luna had some for the brand they were selling.
I went into my direct drive unit to discover the source of binding up, but there were no moving parts inside to spring out and get lost. Difinitely work on a clean unobstructed surface to catch any parts that blast out under spring pressure. A little lube may save your unit, but at 3500 miles I suspect a gear motor might have reached life. NGLI #2 grease might be a little thick; I would try lubriplate if you find the lubrication needs updating.

Already found a gear set on eBay (https://www.ebay.com/itm/Bafang-gea...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649] and Park Tool PPL-1 Polylube 1000 so I am ready to take the plung. I will update my results as I progress, have watched many videos online in preparation so wish me luck LOL...
 
Wow, $37 including shipping. That's a great price. My hub motor was very simple to open. There's quite a few youtube videos to walk you through things.
 
Completed the rear hub motor tear down only to find that all I needed was a good amount of PPL-1 lube as the gear set was completely dry. I now have an extra gear set for future needs, none of my local bike shops wanted to help me out so I am glad I did it myself. Took it out for a few mile ride and the motor is very quite compared to before. I was very impressed with the excellent condition of the original gear set with 3500 miles on the clock. I only cut two of my fingers so that isn’t to bad, now time for a shower and a couple of IPA’s
 
Nice Job! It always pays to do it yourself even if you screw up the first time. I have found YouTube to be very helpful when I have to tackle a new project.
 
Completed the rear hub motor tear down only to find that all I needed was a good amount of PPL-1 lube as the gear set was completely dry. I now have an extra gear set for future needs, none of my local bike shops wanted to help me out so I am glad I did it myself. Took it out for a few mile ride and the motor is very quite compared to before. I was very impressed with the excellent condition of the original gear set with 3500 miles on the clock. I only cut two of my fingers so that isn’t to bad, now time for a shower and a couple of IPA’s
Its by design that you will see very little lube grease in any of these hub motors, since they have nylon gears. You definitely dont want to over-do it, and while it may be quieter for a little while, if there it too much, you run the risk of the lube getting into other places that aren't 'user friendly'. I would have suggested that you just replaced the gear set, especially since you got it already, and then put minimal amount of lube. $37 is nothing to have the gears at the right tolerance. If they are worn and out of tolerance, the extra lube you put on, probably wont keep the motor quiet for very long, so again, hence just makes sense to install the new gears when you have gone to the trouble of opening it, and then be done with it for another 3500 miles or whatever. Nice job though in at least attempting to do it on your own. Even with Youtube vid's and google, not too many real 'gear-heads' left in today's society, let alone people who actually own much more than a screwdriver or hammer. lol. but sad in a way too.
 
Back in my slot car racing days, we considered nylon gears to sorta be self oiling. Still, a little bit of lube is a good idea, and if things quieted down that's a good thing. Congratulations on a job well done.

It doesn't surprise me that your local bike shops were no help. Mine are really anti electric bikes, and my experience has been that often the shops can be snooty and snobbish to anyone that doesn't ride a $4,000 carbon frame bike.. One told me they thought e-bikes were just a fad. I think not, and it's easy enough to see that sales every year are increasing. The prices are excellent now, and reliability and quality are a lot better. The technology is light years ahead of the days of lead acid batteries and 80 lb bikes (which wasn't that long ago actually) which might take you 8-15 miles. With today's demographics showing that the active seniors market is rapidly growing as the population ages, e-bikes will only become more popular. Bike shops that don't see that future run the risk of losing a big share of the market.
 
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Its by design that you will see very little lube grease in any of these hub motors, since they have nylon gears. You definitely dont want to over-do it, and while it may be quieter for a little while, if there it too much, you run the risk of the lube getting into other places that aren't 'user friendly'. I would have suggested that you just replaced the gear set, especially since you got it already, and then put minimal amount of lube. $37 is nothing to have the gears at the right tolerance. If they are worn and out of tolerance, the extra lube you put on, probably wont keep the motor quiet for very long, so again, hence just makes sense to install the new gears when you have gone to the trouble of opening it, and then be done with it for another 3500 miles or whatever. Nice job though in at least attempting to do it on your own. Even with Youtube vid's and google, not too many real 'gear-heads' left in today's society, let alone people who actually own much more than a screwdriver or hammer. lol. but sad in a way too.

Thanks for the great feedback, I will clock in another 1500 miles on the old gear set then install the new gear set. Now that I completed the rear hub project I am on to the next project, replacing front/rear disc brake pads.
 
Back in my slot car racing days, we considered nylon gears to sorta be self oiling. Still, a little bit of lube is a good idea, and if things quieted down that's a good thing. Congratulations on a job well done.

It doesn't surprise me that your local bike shops were no help. Mine are really anti electric bikes, and my experience has been that often the shops can be snooty and snobbish to anyone that doesn't ride a $4,000 carbon frame bike.. One told me they thought e-bikes were just a fad. I think not, and it's easy enough to see that sales every year are increasing. The prices are excellent now, and reliability and quality are a lot better. The technology is light years ahead of the days of lead acid batteries and 80 lb bikes (which wasn't that long ago actually) which might take you 8-15 miles. With today's demographics showing that the active seniors market is rapidly growing as the population ages, e-bikes will only become more popular. Bike shops that don't see that future run the risk of losing a big share of the market.

Thanks for the positive words, my local bike shops here in Florida rent eBikes all day long but do not want to work on them for some reason? It may be that they run them until they begin to fail and just replace instead of repair them?
 
They probably lack the skills and experience to fix them. I'm a pretty good mechanic (was a certified mechanic and service manager at Fiat, Alfa Romeo, Mazda, Toyota and Volvo dealerships), but that was before cars became so electronic. Simple mechanical and electric fixes are no problem for me, but I see that a lot of people here and on other bike forums have tons more electronic experience when it comes to controllers, hub motors, etc.

Bike shops should be able to get at least one person brought up to speed on things like basics diagnosis and replacement (replacing a bad motor or component rather than attempting a fix). Parts availability may be an issue w/ the companies that make the bikes as well.

But all of that is something that can be addressed because the shop that sells, warranties and repairs quality and affordable e-bikes is going to be always growing, while traditional pedal only bike shops won't be. The pedal only shops usually focus on selling low end bikes, high end bikes, and a smattering in between, and that market is static.
 
Thanks for the great feedback, I will clock in another 1500 miles on the old gear set then install the new gear set. Now that I completed the rear hub project I am on to the next project, replacing front/rear disc brake pads.

Replaced the front and rear disc brake pads, much easier than I thought and the brakes now feel amazing compared to the old pads.
 
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