Should this guy have stopped pedalling?

[Bearing Man]

We get a lot of motors in the workshop where the owner has gone with the old adage... I'll fix it when it breaks! Unfortunately, with an ebike motor once a different noise is noticed coming from the motor, it's already costing you more money every pedal stroke!
However, some people try and push the envelope, just that little bit too far! Don't be this guy!

 

[Paulquattro]

Well, he had his money's worth out of that
but like you say he will know how much too.

 

[SquireRides]

Looks okay to me. Thats basically what my cassette looks like...

 

[Bones]

T cut!

 

[Doomanic]

T cut!

Might need to up the ante and go Maguires with that one!

 

[RustyIron]

with an ebike motor once a different noise is noticed coming from the motor,
it's already costing you more money every pedal stroke!

Nice! Guess you'll be eating steak and drinking top-shelf wine thanks to that rider. I can't imagine what the motor sounded like for dozens... hundreds... of miles before it failed.

So is that the sort of job you'll take on, or will the repair cost more than the motor would be worth?

 

[Bearing Man]

Nice! Guess you'll be eating steak and drinking top-shelf wine thanks to that rider. I can't imagine what the motor sounded like for dozens... hundreds... of miles before it failed.

So is that the sort of job you'll take on, or will the repair cost more than the motor would be worth?

Sadly no wine for me. Although it would have been possible to repair this motor, eventually, it was way beyond economical repair and cheaper to offer him one of our reconditioned motors in exchange.

 

[steve_sordy]

This almost makes me wish I rode a Bosch, just so I could get it fixed by @Bearing Man. But I suspect I'll stick to the basically unrepairable Shimano motors that, so far (for me), have never gone wrong. (Touching wood all over the place now).

 

[DeRailled7]

Some days that’s what i imagine my Bosch innards may look like. These motors are not quiet and i never know what’s going on in there. Problem is, there no easy way to have a peek inside or do any maintenance. That’s probably why your customer rode it to the grave.

 

[oceanskipper]

Out of interest how do you think all that dirt etc actually got inside? Was the casing cracked?

 

[steve_sordy]

Out of interest how do you think all that dirt etc actually got inside? Was the casing cracked?

It looks like the gears donated all those filings (the "dirt").

 

[oceanskipper]

It looks like the gears donated all those filings (the "dirt").

Ah, sounds like a reasonable assumption.

 

[Stihldog]

Now this has me thinking. My Bosch Gen4 motor, which has been submerged several times and is reaching 10k+ kms, is still quiet and is working great(Rail9.7). Could it be close to a rebuild? I’m knocking on wood also.

But the motor on my Powerfly (-2k kms) is kinda noisier.
If I had the right tools, would a rebuild kit on standby be a good idea? Or is this a job for a professional? (Rocket Surgery?). I may have the ability and might get a small press, but I’d really like to crack that puppy open before/when it “breaks”.

 

[Stihldog]

We get a lot of motors in the workshop where the owner has gone with the old adage... I'll fix it when it breaks! Unfortunately, with an ebike motor once a different noise is noticed coming from the motor, it's already costing you more money every pedal stroke!
However, some people try and push the envelope, just that little bit too far! Don't be this guy!
View attachment 99618 View attachment 99619 View attachment 99620 View attachment 99621

I just watched a video () and realized the complexity you can face once it’s opened up. Pullers, press, specialty tools, patience etc.
My neighbour has a gen4 with a broken casing bolt. Other than that, this motor sits there gathering dust and still works perfectly. He’s purchased a replacement. But there’s that possibility of sharing this motor or keeping it as a spare, if I can remove the broken casing bolt (torque+ security bolt). Perhaps a machine shop could remove the broken bolt once I did a disassembly for bolt removal access.

Another question; 1- Would you use/recommend a static strap when working near the pcb.
2-What is the material, or sizing, of the reassembly collar used ?
3- Am I over my head and YouTube videos are for “dummies “?(#nothingtoloose)

 

[RustyIron]

I just watched a video and realized the complexity you can face once it’s opened up.

I just watched the video, as well, not because I have a Bosch, but because I'm intrigued by electrical and mechanical contraptions, and bike motors are an amalgamation of both. That thing sure looks tedious to work on. Or maybe it's just watching someone else that's tedious.

Regarding the grounding strap: I don't wear a grounding strap when working on delicate equipment. In my walnut-sized dinosaur brain, a grounding strap when working in close proximity to live circuits creates a greater electrocution hazard. I could be wrong, but I won't change. On a more scientific note, NASA has concluded that wrist straps don't dissipate static electricity buildup sufficiently to protect delicate electronic devices. When working on such devices, I always dissipate static buildup by touching grounded metal before starting. I also minimize contact with components to minimize static electricity AND mechanical damage. Little circuits can be damaged by a little unintended bump.

The case bolt? If it's what I envision, and the bolt hole is exposed on the threaded side, a repair might be possible without disassembly of the motor. I vertical mill is preferable, but it can be easily done on a drill press. If you're good, you can do it with a hand drill. Block up the motor so it is perfectly square and secure, with the female threads pointed up. Center punch the broken fastener as close to center as you can get it. By that, I mean get it pretty damned close to perfect. Use a starter drill to get the hole started. Now use a drill that's smaller than the hole to drill through the fastener. Drill slow, use lubrication, and don't break the drill bit. Often times the drilling process will start walking the broken fastener out. If that's the case, your problem is solved. If it doesn't, move up to a bigger drill bit.

If the broken fastener is extremely stubborn, your drill bit might start hitting the threads. It's not the end of the world. Since you're being very precise, you won't bugger up the threads. I don't think it will get this bad, but you might end up with most of the fastener drilled out, and just the fasteners threads stuck in the hole, and you can't drill any bigger without goofing things up. No worries. Get out your pick, and start picking away a the individual threads down the hole. They come out as little crescents. It's tedious work, but either you do it, or you pay a machinist by the hour to do it for you.

 

[Bearing Man]

Out of interest how do you think all that dirt etc actually got inside? Was the casing cracked?

It looks like the gears donated all those filings (the "dirt").

As Steve has rightly said, this is all metal filings and grease, there is no dirt. Water had destroyed the left hand crankshaft bearing and made its way along the crankshaft to start rusting the gears. Normally, by this time most people would stop and take a look at what was causing all the noise, but this customer may have had a hearing issue!?

 

[Bearing Man]

I just watched a video () and realized the complexity you can face once it’s opened up. Pullers, press, specialty tools, patience etc.
My neighbour has a gen4 with a broken casing bolt. Other than that, this motor sits there gathering dust and still works perfectly. He’s purchased a replacement. But there’s that possibility of sharing this motor or keeping it as a spare, if I can remove the broken casing bolt (torque+ security bolt). Perhaps a machine shop could remove the broken bolt once I did a disassembly for bolt removal access.

Another question; 1- Would you use/recommend a static strap when working near the pcb.
2-What is the material, or sizing, of the reassembly collar used ?
3- Am I over my head and YouTube videos are for “dummies “?(#nothingtoloose)

As Dave said in this video, the Bosch Gen 4 is a bit of a nightmare! And not really suitable for "having a go" in your garage. I am a keen advocate of people being able to fix their own stuff, but this motor is one motor I would not recommend!
What dave Did not tell you is that if you snap a case screw, they are high tensile and almost impossible to drill out! The cases are a very high magnesium content and therefore quite brittle. This makes them very difficult to tap new threads too.
If you snap the torque sensor (and some will!) they are currently unobtainable, although we are working on this and getting the torque sensor cases manufactured.
If you do break one or more of the small petals off the bottom of the armature magnets (very easy to do) it puts the armature out of balance and makes the motor noisy!
Honestly, this is one to leave to the experts unless you have one to train in first!
An earthing strap really should be used if you're going to touch the board components and working on a wooden bench. We tend to use earth bonded steel benches, keeping static to a minimum. We only tend to handle the board by the edges, once out and once back in.
One thing missing in this video was the large circlip that holds the steel gear on. This would need to be removed before removing the drive gear.

 

[RustyMTB]

Don't start me on Bosch circlips...

 

[RustyIron]

The cases are a very high magnesium content and therefore quite brittle.

It's always a bummer when you have to buy something expensive, like a new motor. On the bright side, you'll have something to throw into the campfire.

Get it? Bright side?

 

[Stihldog]

As Dave said in this video, the Bosch Gen 4 is a bit of a nightmare! And not really suitable for "having a go" in your garage. I am a keen advocate of people being able to fix their own stuff, but this motor is one motor I would not recommend!
What dave Did not tell you is that if you snap a case screw, they are high tensile and almost impossible to drill out! The cases are a very high magnesium content and therefore quite brittle. This makes them very difficult to tap new threads too.
If you snap the torque sensor (and some will!) they are currently unobtainable, although we are working on this and getting the torque sensor cases manufactured.
If you do break one or more of the small petals off the bottom of the armature magnets (very easy to do) it puts the armature out of balance and makes the motor noisy!
Honestly, this is one to leave to the experts unless you have one to train in first!
An earthing strap really should be used if you're going to touch the board components and working on a wooden bench. We tend to use earth bonded steel benches, keeping static to a minimum. We only tend to handle the board by the edges, once out and once back in.
One thing missing in this video was the large circlip that holds the steel gear on. This would need to be removed before removing the drive gear.

So not rocket surgery.…but pretty damn close. I’m gonna lower my skill-level.

And my apologies. It’s not a casing bolt but rather a motor bracket bolt. Still, tapping out a broken bolt in magnesium doesn’t sound like fun. I suspect a heavy peddle strike caused this.

 

[Bearing Man]

So not rocket surgery.…but pretty damn close. I’m gonna lower my skill-level.

And my apologies. It’s not a casing bolt but rather a motor bracket bolt. Still, tapping out a broken bolt in magnesium doesn’t sound like fun. I suspect a heavy peddle strike caused this.

That's an easy one, just change the little aluminium bracket, the nut is captivated in that and not the motor itself.

 

[Planemo]

If anyone has a mangled bolt that they can't get out, a decent machine shop may have the equipment to 'spark erode' it. Decent engineering shops are getting harder and harder to find but there still are some around. I've been amazed at what they have achieved when supplying them with some very rare and expensive engine blocks with broken head bolts that you would think would be impossible to remove without destroying the surrounding metal. I'm sure theres a limit with how small a bolt the procedure can go down to but I would think even the casing bolts on e-motors would be fine.

 

[Slapbassmunky]

I don't wear a grounding strap when working on delicate equipment. In my walnut-sized dinosaur brain, a grounding strap when working in close proximity to live circuits creates a greater electrocution hazard. I could be wrong, but I won't change. On a more scientific note, NASA has concluded that wrist straps don't dissipate static electricity buildup sufficiently to protect delicate electronic devices. When working on such devices, I always dissipate static buildup by touching grounded metal before starting. I also minimize contact with components to minimize static electricity AND mechanical damage.

I know it's a little off topic but I'm interested to know where you found out about NASA's conclusions? I've worked in the aerospace (weapons and radar) industry in the UK for 22 years and have seen countless times the damage that can be done. Your e-bike isn't live equipment, there is no hazard. When working on kit in an emergency regularly touching grounded metalwork is a last ditch effort, but normally the nylon in the clothes you're wearing sees to that within a few seconds.

 

[Stihldog]

So I have the motor and cleaned up as best as I could. Hopefully my pic shows enough detail on a perfectly good working motor …except the broken bracket bolt.

Here you might get the idea(forgive my lame highlights).

ī or #5; Mounting bracket showing sheared or broken bolt. I can’t remove the bracket at this time but the threads seem compromised. Part of the bolt is still inside.
#2; My smallest easy-out with a 9/64 drill bit. It seems to fit properly without further damage or damaging the existing threads. I have a drill press.
#3; A T25 security (doesn’t fit) and a TP40 for dropping the motor.
Are the motor bolts a TP25 security pan head?
#4; My MickyMouse torques security set.

I’d be a shame to discard a good working motor because of a single bolt, but I could try. After seeing the rebuild video I would avoid cracking that puppy open.

 

[RustyIron]

Your e-bike isn't live equipment, there is no hazard.

I concur, and never claimed anything to the contrary. Nor did I list my résumé because I'm not trying to convince anyone of anything.

I'm interested to know where you found out about NASA's conclusions? I've worked in the aerospace (weapons and radar) industry in the UK

It took me only a few minutes of googling on electrostatic discharge to come across the NASA report suggesting that wrist straps were insufficient protection for their purposes. I could search through my browsing history to find it, but you can google it just as easily. If the OP wants to wear a wrist strap, that's great. I fully support him... No! I encourage him.

I still stand by my original position that careful handling is far more beneficial than a wrist strap. If your 22 years in the aerospace industry leads you to repair electronic devices in a way different than my own, that's great. It's fun to explore different solutions to the same problem.

 

[Bearing Man]

So I have the motor and cleaned up as best as I could. Hopefully my pic shows enough detail on a perfectly good working motor …except the broken bracket bolt.

I’d be a shame to discard a good working motor because of a single bolt, but I could try. After seeing the rebuild video I would avoid cracking that puppy open.

We can always change the motor case if need be. No need to throw the motor away!

 

[Slapbassmunky]

I concur, and never claimed anything to the contrary. Nor did I list my résumé because I'm not trying to convince anyone of anything.



It took me only a few minutes of googling on electrostatic discharge to come across the NASA report suggesting that wrist straps were insufficient protection for their purposes. I could search through my browsing history to find it, but you can google it just as easily. If the OP wants to wear a wrist strap, that's great. I fully support him... No! I encourage him.

I still stand by my original position that careful handling is far more beneficial than a wrist strap. If your 22 years in the aerospace industry leads you to repair electronic devices in a way different than my own, that's great. It's fun to explore different solutions to the same problem.

I'm starting to see why Gary *ucked off.

Stating my background was not a flex, it was to give an idea of the industry I'm involved in, which funnily enough isn't too far from NASA's in areas. Carefully handling electronics does not work, but it helps when combined with other forms of static protection. However, not using a wrist strap/etc because one report says they don't offer ultimate protection is misleading to people that aren't as clued up as you are.

 

[Stihldog]

We can always change the motor case if need be. No need to throw the motor away!

Thanks for the info/help. Much appreciated. I just ordered a decent set of Torx Plus tamper resistant (1/4” to 3/8” drive). Looks like a TP25 security will work. I’ll add these to my growing set of “rarely used”, but necessary, tools. A puller and press might be in my future .
I can’t throw that motor away 🫡.

 

[Stihldog]

I concur, and never claimed anything to the contrary. Nor did I list my résumé because I'm not trying to convince anyone of anything.



It took me only a few minutes of googling on electrostatic discharge to come across the NASA report suggesting that wrist straps were insufficient protection for their purposes. I could search through my browsing history to find it, but you can google it just as easily. If the OP wants to wear a wrist strap, that's great. I fully support him... No! I encourage him.

I still stand by my original position that careful handling is far more beneficial than a wrist strap. If your 22 years in the aerospace industry leads you to repair electronic devices in a way different than my own, that's great. It's fun to explore different solutions to the same problem.

At an early age (1972) in tech class I was shown the importance of grounding-out before we touched a pcb. A self made grounding strap tethered to my ankle and then to a metal work bench. Later that year I was recruited by Fabricon Canada to finish my schooling in Germany to join R&D into fibre optics, but that was a hard NO from my parents. (Too bad imo.) By the time I was 17 I joined an industry far more important than NASA…The arcade vending industry. My first repair was the video game Pong.

I was encouraged to use a grounding strap while at the bench, but I never used one while in the field. Nothing blew up. I did become an awesome Foose Ball player during my lunch breaks though.

 

[Bearing Man]

Thanks for the info/help. Much appreciated. I just ordered a decent set of Torx Plus tamper resistant (1/4” to 3/8” drive). Looks like a TP25 security will work. I’ll add these to my growing set of “rarely used”, but necessary, tools. A puller and press might be in my future .
I can’t throw that motor away 🫡.

TP25 wont fit, it's a 5 point TS25