Dirty rusty bafang hub

[Scottyf]

Hello all.
Noticed of later the weather, my commute and general aggressive riding style Is beating the crap out my bike. The poor thing needs a bit of an overhaul and some love. But in regards to this I've noticed a more metallic sound coming from my hub motor.

Also noticed a small wobble coming from the back wheel. Noticed when moving the wheel it was all the way round. Thought it's got to be a bearing. Couldn't be the gears or anything else. Axel is tight and running two torque arms now.

Long story short here's some pictures ...

Nice watery goodness. Lovely water and grease mixed in. Surprised it ran with all the water in it. This shows how much was inside.

 

[Scottyf]

Bearing for reference.

And the unsealed bearing making the noise and play.

I'll have to wait till the weekend for a full clean up and re grease.
The bearing Is pretty knackered though. The sealed bearing is ok but might be worth me replacing it anyway.
The open bearing looks worse for wear.

If anyone knows where to buy spares I'm all ears. If not I'm sure I can find something locally. As the outer races are a little battered.

Surprised they didn't use a better bearing but then again I guess there usually better sealed. Part of having a cheaper hub.

Gears and out ring look well and the windings are still a lovely copper colour once there cleaned. This is after 3000 miles at 44v 22amp.

 

[cwah]

wow, that is dirty ugly

I hope when I'll get my bafang it's now going to look like this. How come is it still running?

And do you always limit to 22amps? Never more than 1000W? I'd love to increase to 1500W lol

 

[NRG]

Wow what a mess, wheres the water getting in? I hope that bearing is not a bespoke one...do you have any local engineering shops you take it to...would be better than working your way through a parts catalogue. Just wondering if it will clean up OK especially the planet gears, their bearings and the clutch...maybe a new motor is in order and just swap over the internals?

 

[wurly]

Yuk!
I'm wondering if you have the cable with a loop downwards to stop the water entering the hub through gravity. Might be an idea to seal with silicone as well. I can't imagine it's getting in through the cover. Bearings are usually common standard size, any bearing supplier should have them on the shelf i would have thought. Gears still look in remarkable shape.
Ah i just made out the bearing you mean (looking through the gunge) i still think you may be able to replace the ball bearings or the whole thing.

 

[Deleted member 4366]

There were a couple like that on ES. Like Wurly says, the water runs down the cable and in through the axle. You must make sure that where the cable exits, it goes downwards. I added extra tape to mine just to make sure. You should be able to get the bearing at any local stockist.Just take the old one with you for them to measure. It's probably a standard size, or you can measure the width, ODand ID with a caliper gauge and phone it through, or get the numbers off it, which they'll usually recognise..
Your problem can happen to most hub-motors with a cable that exits the axle. The cable must go down before up to stop water running in - worse during the winter when the water has salt in it.

 

[Riche]

Same motor different issue.

Hi, I have the same motor by the looks of it. But I need to get it welded as a small part of the outer casing where the spoke holes are, broke off when the motor fell off my desk.
My question is how would I go about removing the ring gear as this will melt when welding the aluminium.

I have already had it repaired/welded once before but it has failed again but when they welded the first time it melted one of the locating lugs slightly.

Thanks for any help or suggestions

Rich

 

[Mussels]

Hi, I have the same motor by the looks of it. But I need to get it welded as a small part of the outer casing where the spoke holes are, broke off when the motor fell off my desk.
My question is how would I go about removing the ring gear as this will melt when welding the aluminium.

I have already had it repaired/welded once before but it has failed again but when they welded the first time it melted one of the locating lugs slightly.

Thanks for any help or suggestions

Rich

If it's not a stressed part then how about using something else?
InstaMorph - Moldable Plastic » Ideas or a metal equivalent.

 

[Riche]

Hi Mussels,
The bit that broke off has a spoke hole going through it, so i guess it is a little stressed.
BTW sorry to Scottyf for hijacking this thread. Mods if you want to move it to a new thread thats absolutly fine with me.

Rich

 

[flecc]

We've had a few reported in here with the same problem, as d8veh says, it's water entry via the cable due to inadequate sealing on some motors. It's worth adding more silicone sealant at the entry point on a new motor, and on the types with the small spindle bearings, sealing the external housing entry with some grease to deter water access to the bearings.

 

[Scottyf]

No worries its all technical postings and all useful.

Yeah the cable is now got a rain loop. But the damage is already done to be honest. The bearing this morning was fully battered. So I am back to riding unassisted after today. Not really an issue just takes me longer.

To be honest I'm sure I can have a ride around some local engineering firms round Birmingham and get a bit of help on it. The motor itself works perfectly. I'm suprised it still runs so well.
But the bearing is shafted and because the grease inside is now watered down its no longer doing its job.

The bearing although supports my weight and rotates its a horrible sound and if I keep using it I'll only damage it more. Then there will be metal fragments rotating round that will cause more damage.

I cleaned it up last night but it really needs a soak and a bake to get it back to new and remove the unwated grease.

So a little help from you wonderful people. What will be the best thing for removing the grease?
Cleaning up the inners?

I'd like to fit a better bearing but believe the one that is shot uses a race that the ball bearings sit in with a couple of cups that sit on top to hold the bearings in. I believe they where meant to be all one piece but maybe with the extra speed / me and the occasional curb hopping i've broken the bearing open. I'm not sure.

The bearing is then coupled to the side plate holding the freewheel cassette in place. Thats what supports the bearing on that side. (left hand side if you was sitting on the bike).

 

[wurly]

I know the hub is made in China.
Get either german or japanese made bearings, not chinese. They almost certainly last much longer. SKF or Timken if possible but then again you may not have that choice.

 

[Scottyf]

Yeah SKF was what came to my mind first off. I'm sure somewhere like RSTOOLS would be able to supply it.
But I may just send it on to my friend at his engineering plant and see what he can come up with.

Either was I refuse to let a perfectly good hub die becasue of a bearing and some water.
That and I'm tight.

 

[alban]

Yes on ES there was a mention of condensation being a problem too and causing rust. That's a prob with leaving it outside in the cold of course and not using it twice a day thus heating the motor and driving off the water. Dilemma is - unless it's 100% sealed - there's nowhere for the condensate to run out if you seal it. There was a thread there also about using some kind of water repellant/ lubricant spray before winter rather than grease which can gum gears up - seemed to work.
A current thread is here rusty hub

 

[Scottyf]

Thanks for the info and link I'll give it a read later on for some hints and tips. But for now its about getting that bearing up and running and getting the grease out.

Either way its going to be a messy job.

Hopefully a new bearing will see me right and I'll be able to get back on electric fast. For now though its back to my own leg power to get to work and back!

Oh well I could do with loosing a bit of winter timber!

 

[Deleted member 4366]

Yes on ES there was a mention of condensation being a problem too and causing rust. That's a prob with leaving it outside in the cold of course and not using it twice a day thus heating the motor and driving off the water. Dilemma is - unless it's 100% sealed - there's nowhere for the condensate to run out if you seal it. There was a thread there also about using some kind of water repellant/ lubricant spray before winter rather than grease which can gum gears up - seemed to work.
A current thread is here rusty hub

I've seen those posts too, and I think here there's mention of condensation in controllers. Personally, I think it's a load of hogwash. Both motors and controllers run above ambient, so how can they attract condensation. No, I believe the problem is much more simple - water comes in through a gap somewhere.

Scotty. Petrol will get rid of the grease perfectly. I've done similar cleaning jobs many times with it. I don't think it will take the lacquer off the windings, but, if you can, check first. Anyone else know?

 

[flecc]

I've seen those posts too, and I think here there's mention of condensation in controllers. Personally, I think it's a load of hogwash. Both motors and controllers run above ambient, so how can they attract condensation. No, I believe the problem is much more simple - water comes in through a gap somewhere.

I'm also sure that's right. With additional silicone sealant in the cable entry from new and grease plugging the bearing sides in the side plates of the hub shell, internally mine always look as below despite many times caught by heavy rain:

 

[Scottyf]

Oh yes forgot about petrol. Used that before to remove grease. Forgot the old tricks.

Managed to clean them up a little bit using so household goods.
Will do the petrol outside and not in the apartment.

My only issue currently is getting the old bearing that collapsed out. I was hoping to knock it out with a drive, hammer but I have nothing sturdy enough in the apartment to give it a good whack safely. So I'll have to pop it down to my friend at rftools and get him to drive it out.

I'll get him to measure the bearings as well while his there. For others and reference.

For now I'm riding unassisted and could do with the extra exercise.
Hopefully I can get it fully cleaned up and new bearings fitted since they have now fully collapsed.

 

[Scottyf]

 

[Deleted member 4366]

Just a thought: don't let any petrol near that sealed bearing because it'l take the grease out and you won't be able to put any more in. It looks clean enough already anyway. It might be worth changing the seals because they don't cost much. Did you not find a number on the damaged bearing?