Bafang Ultra Motor (M620) Ridden Very Gently for 3,000 Miles - Service Required or Not Necessarily?

[Nvreloader]

Kind'a looks like it was rode hard and put away wet.....
as the saying goes.

 

[PCeBiker]

Kind'a looks like it was rode hard and put away wet.....
as the saying goes.

Not really.
It's only seen rain once and I rode on wet gravel 3-4 times that sprayed slop everywhere because I removed my fenders.

I'm a fair weather rider and avoid rain because it's a fricken mess and riding ain't no fun when you're cold and wet.

However, the one day I got "caught in the rain" 20 km out.
It was a cloudy day with a 30% chance of rain, and the road ahead was wet, but I just rode on. The water got Deep and I figured it must have Fricken Poured !!

I was getting completely covered in gravelly slop so I started riding on the grass to get some cleaner spray on everything.
My googles were covered in road spray and when I tried to wipe them clean, it just smeared ?
Then I caught some in my face and it tasted like salt and vinegar chips ?

I'm like WTF is going on??

Then I passed a farm tractor that was towing two HUGE empty water tanks of brine solution that just got dumped on the road. It keeps the dust down in the summer.

So my e-bike and I were covered in concentrated sodium, calcium, and potassium chloride solutions, which was probably richer in salt than the Dead Sea?

I wonder if my ebike would float in the Dead Sea ?
Or would it burst into flames ?


Aaanyway,.. the gravel roads aren't just dusty with grit that grinds away at every moving part of my e-bike, it's also Really Salty, so it does a better job of wearing out my ebike with both a grinding and dissolving action.


I do occasionally wash my e-bike but only when it's covered in crap because I keep my e-bikes in the house.

Some days are worse than others when it comes to getting full of

 

[m@Robertson]

Put all the nuts bolts screws and washers back where they came from as soon as you get something apart so you don't lose it or forget where it goes.

Yikes. For your typical hub motor, all you should be doing is take off the casing cover. Leave everything in one piece. Grease the teeth on the outer gear in the motor casing. Maybe thumb a little on the inside of the planetary to make sure the sun gear gets a dose. And then put it back together. No need to take anything apart.

 

[PCeBiker]

No need to take anything apart.

I always get carried away and take everything apart.

I like to know what's inside, how it works, and how to fix it when I break it after taking it apart for no good reason.
I spend hours trying to find a good reason, then buy tools I never needed.

 

[PCeBiker]

Grease the teeth on the outer gear in the motor casing. Maybe thumb a little on the inside of the planetary to make sure the sun gear gets a dose. And then put it back together.

I didn't like seeing how some of the old grease got flung through the holes in the housing and into the motor.

I wanted to pull the armature out to check if there is any grease on the magnets where it could drag on housing, but I'm just going to leave it.

I've been spinning up the gear assembly inside the housing then removing the globs of grease and cleaning the face plate to help prevent any new grease from getting inside the motor.

I figure a safe place to stack up a bit of spare grease is below the teeth of outer hub?

I want to keep the space above the teeth and the surface of the armature clean so it doesn't drag.

There's Very little clearance between the surfaces on the inner, outer and middle sides of the armature/hub and you don't want grease on any of it.
None of those surfaces touch each other and shouldn't be greased.

I still need to spread the grease around a bit.
I keep reinstalling the innards, spinning them up then checking for globs and spray.

I'm being completely anal about all this.
I could have greased my motor in ½ an hour. I've been at it for a week now.
I've got till spring to get it done.

I've gotta take my rear shock apart too, because it ain't broke yet.

@mail_e36
I know that you have a mid-drive motor, but it's very similar to a hub motor in that you don't want too much grease clogging up the gears creating drag, and you don't want it getting into your electronics.

 

[m@Robertson]

It'll be fine without disassembly.

You need to use a small kids' paintbrush to put grease on the outer gear and stop slopping it around with your fingers

 

[m@Robertson]

That freewheel is garbage. Throw it away and replace it with something that isn't going to rust out like that. A Shimano freewheel (a real one not one from AliExpress) or maybe better yet get a DNP that has a wider range - is going to give much better engagement vs. that rust bucket.

Don't worry about the lock ring tool. Thats for taking the freewheel apart once its off the bike.

DO NOT use grease on a freewheel internally What you are supposed to do is use oil. The best oil used to be (and still is) Phil Wood Tenacious Oil in the pretty blue bottle. It is super thick and ridiculously expensive. Instead.... use chain saw oil. Just as thick, sold at Home Depot and way cheaper, although I have a bottle of Phil oil from like 1990 that is still at least half full.

What you do is lay the freewheel at an angle on a workbench, inside side up. Then drip a drop of oil into the mechanism. Spin it a few degrees. Do it again. Repeat. You will find the freewheel seems to collect oil like there's a secret bucket hiding inside of it as it can take WAY more than you would think without dripping out the other side. The freewheel will quiet way down as the oil accumulates inside.

It has to be super thick oil. Thats the big thing to remember.

 

[PCeBiker]

That freewheel is garbage. Throw it away and replace it with something that isn't going to rust out like that.

I almost Never pedal.
I have over 3,800 km on my e-bike and I've only pedaled for about 50-100 km of that.

My entire drive-line is sitting idle almost all the time.
I leave it in second gear, and will occasionally add to my acceleration from a stop to cross a road, but don't even bother shifting gears to keep up. When my cadence spins up too fast, I just stop pedaling, and I've crossed the road.

I've thought about removing the whole drive line, but then my e-bike isn't legal, and I Really Like knowing that I can pedal my e-bike in an emergency if I have to.

I also ride no-hands over 90% of the time as well.
I've been considering removing the handlebars, but I need somewhere to mount my brake levers.
Maybe foot activated brakes?

Don't worry about the lock ring tool. Thats for taking the freewheel apart once its off the bike.

I wasn't really sure how it all comes apart, but it looks like the highest gear is separate and replaceable. It's a different color and doesn't line up with the other sprockets.

DO NOT use grease on a freewheel internally
Instead.... use chain saw oil.

Cool !!

I've got an electric chain saw with the oil for it. (I've used it twice for 20 minutes, but the chain probably has more miles on it than my bike chain. )

What you do is lay the freewheel at an angle on a workbench, inside side up. Then drip a drop of oil into the mechanism.

OK Thanks I'll do that.
I was wondering what to use. I just want to stop the rust so the freewheel won't hopefully be seized if it ever needed to come off.

I've been looking for an excuse to remove the freewheel, and now I have one.

Now I can properly clean it up and grease the seal.
I don't want crap getting into my motor.

Now to see if my fake two dollar freewheel tool can get the freewheel off without breaking?
It's specially hardened with black paint.

Oh well,.. if it breaks I've got an excuse to buy the proper Park Tool version.

I'll heat it up the freewheel with my heat gun first and let it soak in some penetrating oil first to help get it off.

I figure the fact that I don't pedal should have helped to keep it from seizing on there?

 

[m@Robertson]

If you have if off the bike... it is disassembled. Don't even try to take it apart further. And based on what I am seeing its junk anyway not something remotely worth saving. Brand new one like that costs around $2 on Temu/Ali. Really. Even this nice Shimano one (that is really Shimano) is only $18.

Freewheel, Shimano

Shimano freewheels Brownish gold cogs (color, not material) with a black big one. Reliable Shimano removal system. Anyway, Shimano backs 'em, so they're good. new for 2020: they are all (mostly) silver, not brownish, they come with a removable pie plate spoke protector, and there's a 6 speed...

www.rivbike.com

Look around some. A real Shimano doesn't have that lock ring, and wouldn't become a rust bucket like that. Real Shimano freewheels say 'MegaRange' not 'MegaDrive' Throw it away.

I asked Senator Vreenak for his analysis:

 

[PCeBiker]

If you have if off the bike... it is disassembled.

It's sorta off the bike.
It's still connected to the motors backing plate, but I can get in there with an oil dropper needle to add oil.

I'll just oil it and leave well enough alone.

I don't need to remove it from the plate.

 

[m@Robertson]

If you do that you are wasting your time. All you are doing is oiling the exterior and it'll never get inside. You have to drip oil directly into the bearings from the back.

This vid is tee'd up to the spot where he shows you the seam you have to attack. Also you can see why I use the trigger spray WD40 rather than the aerosol. Tons less waste.

 

[PCeBiker]

OK, I'll try to get the freewheel off, and go from there.
As long as I get my bike back together before spring.

That gives me time to order the proper freewheel tool if I need it.

Maybe I'll just buy the proper Park Tool freewheel remover now?

It's Christmas time, and buying new tools is Always Fun.

 

[m@Robertson]

I use the same cheap tool sometimes. They work fine on splined derailleurs. I have some good ones and some cheap ones (I've got some old classic Maillard, Regina and Suntour freewheels that date back to when freewheels were top quality items). The one I use depends on the one I can find at the moment. I recently started a project... a bin whose purpose is to hold every unique-to-bicycles tool I own. Ever since I moved from Fresno and lost my workshop, I don't know where anything is anymore.

The thing I really need that I can't find is my star nut setting tool. I have a really good one I got cheap, and the damn things are $25 now. Guaranteed the best way for me to find it is to buy a new one. I have a few weeks until I need it so there's still hope.

 

[PCeBiker]

I use the same cheap tool sometimes. They work fine on splined derailleurs.

I bought this bike tool kit when I got my first e-bike a couple of years ago,..

I figure that every tool is "good enough" except probably the freewheel removal tool?

The tool has really thin walls, and I was worried about snapping the splined "collar" off inside the freewheel and getting it jammed inside?

But with the axle removed, I can reach in from the other side and pound it out if that happens.


I remember removing freewheels when I was a kid, and they were seized up really good. They're just like pedals that work themselves on tighter as you pedal.
I didn't have any special tools so I used a flathead screwdriver and a hammer to pound on the little detent/holes to unscrew it.

Then, when I did manage to get the freewheel off, about 70 little ball bearings fell out from inside.

I remember putting a thin layer of grease on the races inside to "stick" the ball bearings to, to hold them in place when I put it back together.

 

[m@Robertson]

The freewheel tool is fine. its the crank remover I would be afraid of. You strip threads on a crankarm and you are truly f**ked. And the chain whip is too short to be really any good.

The park crankarm remover is only like $18 and a decent chain whip is maybe $10.

Pounding on the holes is not the way you remove the freewheel. Thats how you disassemble it. Different thing entirely. There is no need to get inside that freewheel. You can wash the crud out of a removed freewheel with a proper solvent. The video I linked showed a guy doing it with WD40 blasts. Another way is to dip it into a solvent and dunk it repeatedly (or swish it around) after it sits in the tank for a while.

Nobody really works on freewheel rebuilds anymore because they are disposable bottom-of-the-line junk now. Decades ago, if you had, say, a Maillard freewheel with magnesium alloy cogs you did things differently. Or you wore out one of your alloy cogs on your Regina you replaced that one cog. But those days are long gone. Just buy another one. It'll be much better than the one you have, guaranteed, and it'll last without the kind of damage you have now.

 

[m@Robertson]

here... 9 bucks and you get a whip with good leverage, a second freewheel tool and a cassette tool to boot.

Amazon.com

And for once the Park crank puller is reasonably priced as these things go.

Amazon.com

I have the Park chain whip and its $35 and its really long for great leverage... and it has an end on it that will fit over a cassette tool so it becomes a wrench handle... but its overkill. I bought it cuz I needed one when I was out of town and my tool was at my home shop so I took what I could get at the LBS.

 

[PCeBiker]

The freewheel tool is fine. its the crank remover I would be afraid of. You strip threads on a crankarm and you are truly f**ked.

Huh, I wouldn't have thunk that?

I am aware of seized crank arms and figured the tool would be at least as strong as the alloy crank arm with its tiny threads?

I didn't even know that there was a crank arm tool back in the 80's.
I thought the threads were just to thread on the little hub cap that covers up the axle bolt or nut.
I just hammered the snot out it with crow bars and chisels until it came off.

The park crankarm remover is only like $18 and a decent chain whip is maybe $10.

I'll consider the crank arm tool if I ever need it, and maybe a longer chain whip, but I could just put a cheater bar on my chain whip?

Pounding on the holes is not the way you remove the freewheel. Thats how you disassemble it.

Yeah, I was taking it apart at the time. The freewheel was all crusty inside.

Different thing entirely. There is no need to get inside that freewheel. You can wash the crud out of a removed freewheel with a proper solvent. The video I linked showed a guy doing it with WD40 blasts. Another way is to dip it into a solvent and dunk it repeatedly (or shish it around) after it sits in the tank for a while.

Mine is soaking in penetrating oil now to help free it up.
I'll try removing it tomorrow.

. Just buy another one. It'll be much better than the one you have, guaranteed, and it'll last without the kind of damage you have now.

I did find a Shimano version of my freewheel on AliExpress,..

That's CAD all in with shipping, duty and tax.
(I don't pay duty if the item is less than about $150)

here... 9 bucks and you get a whip with good leverage, a second freewheel tool and a cassette tool to boot.

Amazon.com

And for once the Park crank puller is reasonably priced as these things go.

Amazon.com

I have the Park chain whip and its $35 and its really long for great leverage... and it has an end on it that will fit over a cassette tool so it becomes a wrench handle... but its overkill. I bought it cuz I needed one when I was out of town and my tool was at my home shop so I took what I could get at the LBS.

Those are all US dollars, and they charge an import fee to ship it to Canada, but there's similar items on Amazon.ca


So just to be clear,.. I shouldn't need any of those tools to remove and clean up my freewheel right?

I don't see any need to remove my crank arms or bottom bracket any time in the near future, especially since I don't pedal.
So I might have everything I need right now except a new freewheel.