Bearings shot so soon? - mostly spokes

[molybdenum]

I have an odd clicking noise in my hub motor. It occurs regardless of whether I pedal. When I move the bike slowly, I hear a high pitched sound in the hub area (increasing in pitch as I walk it faster). When I ride/put my weight on the bike, I hear this distinctive triple click. I've double checked everything and I'm certain there is nothing rubbing. I even removed the rear disc brakes to eliminate any possibility of rubbing.

The clyte HS3540 motor has about 400 Km on it. I ride exclusively paved roads in decent condition at around 40-60 kph with the odd burst to 65-70 kph. I monitor temperatures with a 10K thermistor and they usually do not exceed 90C. I've never gone over 110C.

Edit: With the help of es members, I have been able to determine the clicking noise was caused by loose spokes:

Here's a short video showing the clicking sound caused by three loose spokes:
[youtube]KazTTw_F3F8[/youtube]

Before I tear the motor apart, I thought I'd check if anyone has experienced something familiar? Do you think it's the bearings?

 

[alsmith]

I had to change the bearings on my crystalyte 5300 after a very short life.
Are all of the spokes tensioned ok? Can you feel any movement at the rim from side to side? I don't think the sound is like bearings though, but if there's enough play something else could be catching maybe on a sideplate. I hope it isn't loose magnets like the recent cromotor posts- I think you're going to have to strip it down- look for shiney metal where things have been rubbing together, and check the magnets are properly glued. Don't forget to look for rubbing on the magnets and stator as well as the sideplates
While you have it stripped check the bearings - feel for any play, tight spots or inconsistency of smooth motion. You will also be able to look for poor machining of the parts that the bearings fit in and on (side casing and axle)- mine has the axle slack on one side and the casing slack on the other side. There are good sealants to help bearing installation for these issues- I used one and it helped. The original bearings are cheap crap, they may or may not be the cause but I'd change then for good ones like SKF or FAG (aka INA). Also NSK (aka RHP) or TIMKEN are good.
I noticed the slack on mine within a couple of thousand miles, and they were starting to rust too so I considered it as a maintenance essential.

 

[zener]

Yep its eighter a bearing or something is rubbing on the sidecovers from inside or its the freewheel.
Seems you have to open it up.

 

[zener]

I'd change then for good ones like SKF or FAG (aka INA). Also NSK (aka RHP) or TIMKEN are good.

The brand isnt that important. Buy the Stainless Steel bearings with 2RS and rust problems are a thing of the past.

 

[alsmith]

I'd change then for good ones like SKF or FAG (aka INA). Also NSK (aka RHP) or TIMKEN are good.

The brand isnt that important. Buy the Stainless Steel bearings with 2RS and rust problems are a thing of the past.

There are cheap bearings that are crap- crytalyte fit them. There are brands that are far superior to other bearings.
You need to be careful if you choose to use stainless steel bearings- Martensitic Stainless Steel (prefix "S") is actually slightly softer than 'normal' chrome steel so has lower load ratings and will corrode in salt water or salt spray and has poor resistance to acids/alkalis. AISI440 grade the load capacity is approximately 20 percent less than chrome steel so life ratings will be reduced and it will corrode in salt water or salt spray. AISI316 Austenitic Stainless Steel (prefix "S316") has excellent corrosion resistance to water, salt water and chemicals, but is expensive due to low production quantities, only semi-precision grades are possible and they are only suitable for very low loads and low speed.


Stainless steels advantage is they are good to 300°C, bur the 150°C of the normal bearings is good enough for our motors.


It's your choice, use stainless bearings if that's what you want, but the sensible choice is to use the 'normal' chrome steel so have higher hardness so longer life ratings and are lower cost.
And use a quality brand.

 

[zener]

I'd change then for good ones like SKF or FAG (aka INA). Also NSK (aka RHP) or TIMKEN are good.

The brand isnt that important. Buy the Stainless Steel bearings with 2RS and rust problems are a thing of the past.

There are cheap bearings that are crap- crytalyte fit them. There are brands that are far superior to other bearings.
You need to be careful if you choose to use stainless steel bearings- Martensitic Stainless Steel (prefix "S") is actually slightly softer than 'normal' chrome steel so has lower load ratings and will corrode in salt water or salt spray and has poor resistance to acids/alkalis. AISI440 grade the load capacity is approximately 20 percent less than chrome steel so life ratings will be reduced and it will corrode in salt water or salt spray. AISI316 Austenitic Stainless Steel (prefix "S316") has excellent corrosion resistance to water, salt water and chemicals, but is expensive due to low production quantities, only semi-precision grades are possible and they are only suitable for very low loads and low speed.


Stainless steels advantage is they are good to 300°C, bur the 150°C of the normal bearings is good enough for our motors.


It's your choice, use stainless bearings if that's what you want, but the sensible choice is to use the 'normal' chrome steel so have higher hardness so longer life ratings and are lower cost.
And use a quality brand.

Accepted.
If u ride a sealed hub buy the normal harder steel from brand.
If u drive vented and also planed to spray water on it to cool it down or ride in the rain than buy stainless or ceramiic if u have the money.

 

[John in CR]

"Bearings shot so soon?"

Soon, the only 9C I purchased was new and the bearings were bad. They must have gotten damaged while pressing them in. Your sound definitely needs addressing, but doesn't sound like a bearing problem.

Mark both covers and matching spots on the ring so you can install them in the same orientation they came from the factory. Of course, that's more important if opening a motor that runs well with no rubbing, because sometimes a different orientation of a cover can result in rubbing.

 

[molybdenum]

Thanks for the responses everyone!

Upon reconsideration, I'm thinking it's probably a loose magnet, though it might be the freewheel, which does rotate wonky thanks to the precision engineering of the threaded hub cover. If sticking an extra washer between the hub and freewheel doesn't solve it, I'll need to pull the motor apart; while I'm in there, I'll definitely be upgrading the bearings, so the info on bearings is invaluable.

 

[Drunkskunk]

As it happens, both my Clytes lost their bearings in the first 1000 miles, though that happened 7 years apart. Timkens for the first one, and never had another problem.
This time I used Toyo, as it's what the local shop had. But apparently they are the OEM bearings for Toyota. Good so far, but I don't have 7 years of wear on them yet, either.

What ever that sound is, it sounds like the covers need to come off.

 

[MAGICPIE3FOCUSPOWER]

I have used SKF or Vag very cheap and good.
Running time is about 20000 km and they are still good.
Only some rust, but just grease them good, very important.

For pressing and removing just use some nuts sockets and a hammer :lol:

 

[velias]

I had an old crystalyte, after 5 years/12K miles, it was making a clicking/rattling sound as well as the grinding/scratching sound from the bearings. The motor would not free spin very well either.

Turns out there was a small metal clip that must have been holding wires down that broke off inside and was tumbling around, getting ground up.

But when i opened it up there was tons of rust and it was a lost cause, cheaper/easier to buy a new one than waste days cleaning it up putting in new bearings.

Sounds like theres something tumbling around in there.

 

[d8veh]

Are you sure it's not your spokes?

 

[molybdenum]

Are you sure it's not your spokes?

I just returned from 9 days of camping with the family; sadly, no ebikes though we brought our standard bikes and had a blast.

I found three very loose spokes but my spoke wrench does not fit the spokes that came with the HS3540 hub/wheel assembly. Later when I have time, I will try to tighten the best I can with a wrench and see if the noise goes away!

I've never had spokes this loose before so this could be it - hopefully an easy fix!

 

[alsmith]

I hope that sorts it for you.
If you have a spare smaller spoke spanner and a small file you can open it out - it's usually just 0.2mm (8 thou' in old money) so check frequently for fit and keep the file straight and sqaure so you don't end up with rounded faces that may slip or damage the nipple. If it's like my oem crystalyte europe built wheel the spokes were at full adjustment so I used washers until I could fit proper length spokes.

 

[cal3thousand]

Are you sure it's not your spokes?

That was my first instinct.



OP: Did you happen to test the motor for noises with the wheel in the air? That would help in determining if it was a motor issue or a wheel build issue.

 

[molybdenum]

Are you sure it's not your spokes?

That was my first instinct.



OP: Did you happen to test the motor for noises with the wheel in the air? That would help in determining if it was a motor issue or a wheel build issue.

d8veh and cal3thousand: +2

I finally managed to look at it and tightened all the spokes - presto, the clanking noise is gone!

The build quality of the wheel is utter crap and I can see it causing me grief down the road. I'll be sure to true the wheel when I get my hands on the proper size spoke wrench.

There is still the high pitched groaning sound when I push the bike, which cropped up at around 300 km; this sound originally led me to believe the clanking was the bearings (I'll take video tomorrow when it's light out). The noise does sound like pressure in the bearing area, though there doesn't seem to be notable extra resistance when turning the wheel. It seems I am suffering from two different problems and I do expect to have bearing failure in the near future.

I've edited the original post so everyone reading this will know what loose spokes sound like.

For now, it's ridable

 

[d8veh]

I've often had those sort of noises on motors during the first 500 miles or so. Luckily, they always went away again as the miles increased, so don't panic just yet.

 

[Ykick]

DD (direct drive) motors will make odd noises due to the way low end controllers chop up the DC. Those noises may or may not change how you hear them due to spoke tension. Pure sine wave controllers can practically minimize that noise. Or, we just learn to avoid certain RPMs at certain loads.

You are correct Chinese wheel build quality is utter crap. Not even worth my time to buy/ship laced motor wheels anymore. I only buy loose motors and lace my own wheels using good eyelet rims and 13/14ga butted spokes from Danscomp. Those 13/14ga spokes aren't listed on their website but available when you call in spoke orders for 50 cents ea w/nipples.

1 cross lacing is rather easy to wrap your head around and a careful novice can achieve good results. But in the meantime, grab a wrench and practice tensioning and truing your current wheel until it drives you mad enough to rebuild it.

For future reference any bearing failure capable of creating noise can/will be felt when turning the wheel by hand.

 

[cal3thousand]

Glad you got that sorted out. Now to think about eventual upgrades to the wheel build itself so this doesn't creep back up in 100 miles.

14/15 G double butted SS Sapim is what I recommend for price/quality

 

[Ykick]

Glad you got that sorted out. Now to think about eventual upgrades to the wheel build itself so this doesn't creep back up in 100 miles.

14/15 G double butted SS Sapim is what I recommend for price/quality

Would you recommend washers under spoke heads around the motor flange?

 

[cal3thousand]

Glad you got that sorted out. Now to think about eventual upgrades to the wheel build itself so this doesn't creep back up in 100 miles.

14/15 G double butted SS Sapim is what I recommend for price/quality

Would you recommend washers under spoke heads around the motor flange?

Only if they don't sit in there properly. Most of the time, it may look a little loose, but as long as the heads are larger than the hole, I usually don't do anything. Having said that though, one of my motors (HT3525) does have washers on the heads but they might not even be necessary. It's also not easy to find those tiny little things locally.

 

[alsmith]

I put brass washers on mine when I rebuilt it but I think I'll never really know if there has been any real advantage or not. The cost is minimal and I don't think there could beeny negative effects. The washers give a nice snug fit and follow the taper of the the spoke and the hub so I feel it is probably better with the washers.

 

[d8veh]

I put brass washers on mine when I rebuilt it but I think I'll never really know if there has been any real advantage or not. The cost is minimal and I don't think there could beeny negative effects. The washers give a nice snug fit and follow the taper of the the spoke and the hub so I feel it is probably better with the washers.

Copper is a long way from aluminium in the electrochemical series. In the winter with salt on the roads, that should make a nice battery. Keep an eye on them for corrosion. I think we had it before on this forum.

 

[alsmith]

will do, thanks

 

[molybdenum]

Thanks for all the great advise everyone. I can see a bearing change in my near future (if only as prophylaxis against inevitable failure of the crap stock bearings), so I really appreciate the info on replacements,. I'll probably clean and apply epoxy to the stator and magnets while I have the motor open, aiming to complete this before the rainy season.

I'm definitely going to re-lace the hub in about a month from now. I'll probably opt for the 13-14Ga Sapim Spoke Set from ebikes.ca since they're located a short ride from my work. Also, the stock alex rim has holes drilled for the crappy stock 12Ga spokes, so I'll be putting in washers as well. I might even opt for a better rim 8)

btw, the mysterious noise has mysteriously vanished