Stromer motor water ingress then freezing problem

[kmosdell]

Has anyone have an issue with ingress of water in Stromer's rear motor hub? I have a 2019 ST1X noticed this issue when my rear wheel started freeze up after a cold overnight in the garage. My garage regularly goes to -15 to -20°C in the dead of winter and I regularly ride in salty/wet/cold conditions. I took the wheel and cassette off to inspect it and noticed little to no grease where the freehub and pawls meets the teeth (possibly water ingress from there?). I thought the motor would be completely sealed.

Dealer was able to warranty a new motor and said the issue could be from condensation from the hot motor windings cooling in a cold garage after a ride. The issue hasn't occurred since (but could be because of the warmer weather now). I made sure to grease the hell out every possible ingress point on new motor. Wonder would this issue come back especially when my warranty expires during a future winter.

Here's a vid and pics:

https://imgur.com/a/AlCQc0r

 

[Johnny]

Dealer was able to warranty a new motor and said the issue could be from condensation from the hot motor windings cooling in a cold garage after a ride. The issue hasn't occurred since (but could be because of the warmer weather now). I made sure to grease the hell out every possible ingress point on new motor. Wonder would this issue come back especially when my warranty expires during a future winter.

I have commuted under salt, snow and cold conditions.
These motors are supposed to be sealed but salt and snow are very hard on ANY ebike motor, not just hubs, mid drives will suffer the same fate. I think grease will help significantly however after a ride I would take the bike to a warm place to dry first. I think your real problem here is leaving it in your cold garage after the ride which is barely any different than outside.
Also what is your cleaning interval ? When riding in salt and snow you should clean the bike, at least rinse(lightly, I use a garden sprayer with warm water) and bring it to a warm place to dry, every week or so.

 

[bluecat]

See below how my Stromer looks like after a typical winter ride. No more gear shifting, all frozen. Use either a heating device or some winter car window cleaner liquid.

But never ever water goes into the motor hull. If this happens, it's all over.

 

[kmosdell]

I think your real problem here is leaving it in your cold garage after the ride which is barely any different than outside.

This is no different than me leaving the bike lock outside when I arrive at work except now my bike is exposed to the elements.

Also what is your cleaning interval ?

I dry/lube my chain after every wet ride. At least once a week I dunk a bucket of hot water on the frame to wash off the salt/melt snow.. Not ideal for this issue I know. After I got my new motor, I've just been wiping the frame with a wet rag and trying to clean my drivetrain with a brush.

 

[Johnny]

This is no different than me leaving the bike lock outside when I arrive at work except now my bike is exposed to the elements.

I dry/lube my chain after every wet ride. At least once a week I dunk a bucket of hot water on the frame to wash off the salt/melt snow.. Not ideal for this issue I know. After I got my new motor, I've just been wiping the frame with a wet rag and trying to clean my drivetrain with a brush.

When the temperatures are very low, I wouldn't leave the bike outside, can you bring it inside where you work?
Also dunking hot water over the bike may not be the best practice. I rinse the bike by a light spray of warm water(again garden sprayers are perfect for that) and wipe afterwards.

Was there water inside the motor ? Pictures would be great.

 

[kmosdell]

Was there water inside the motor ? Pictures would be great.

I could definitely hear dripping in the motor when I moved it around. I or the shop wasn't able open the motor on the spot.

 

[kmosdell]

See below how my Stromer looks like after a typical winter ride. No more gear shifting, all frozen. Use either a heating device or some winter car window cleaner liquid.

But never ever water goes into the motor hull. If this happens, it's all over.

Suddenly the new belt drive ebikes with internal gears look more appealing.

 

[Johnny]

I could definitely hear dripping in the motor when I moved it around. I or the shop wasn't able open the motor on the spot.

If there is condensation in the motor and you leave it outside then as your shop suggested that's probably why it froze. But more importantly that is going to cause rust inside so even if it doesn't freeze it will still eventually cause problems.

The conditions you are riding are hard. I am seeing lots of salt deposits on your motor and bike in general. If water carries that salt inside eventually your seals may fail which maybe what happened to you(dunking hot water on the bike may also contribute to that).

I think greasing is a good idea. I don't know what kind of grease should be used in your case though, so it would be best if you send Stromer HQ an email and take their advice on which grease to use and what points to use it to prevent damage from salt and snow.

 

[kmosdell]

If there is condensation in the motor and you leave it outside then as your shop suggested that's probably why it froze

Not sure the solution is to bring it inside either as the whole bike get condensations (like glasses fogging up walking in from cold outside) as you can see in my first pic.

your seals may fail which maybe what happened to you

Thing is, I didn't even see a seal on the cassette side on the old motor or new. The whole cassette and freewheel mechanism can just pop out from the hub easily. I'm guessing the 20nm of the axle keeps everything together. Perhaps a design flaw of the Cyro motor?

what kind of grease

The shop recommended marine grease so I saturated the living hell of the pawls and teeth and I guess it's been holding up so far.

Dealer also never had anyone have this issue before. They regularly deal with food courier riders who never wash their bike during winter or service it for like 4000km. So maybe I just got a defective motor? Not sure..

 

[Johnny]

Not sure the solution is to bring it inside either as the whole bike get condensations (like glasses fogging up walking in from cold outside) as you can see in my first pic.

What I am trying to say is that if you let it dry inside you will prevent accumulation, if there is any.

The whole cassette and freewheel mechanism can just pop out from the hub easily.

I believe what ST1X has a hub (only the oldest generation, st1, used freewheel if I am not mistaken) not a freewheel, what you took out should be a freehub cassette body (designed to be replaceable). Now what you are saying is weird, it should not come out easily. At least in my Syno drive it was just like any other cassette and hub body (I didn't have the need to change the hub body yet, next time I take off the rear wheel I can check it). Granted I don't have experience with Cyro drive (maybe someone who has can chime in) but still I don't think what you are saying is normal. That very well be the problem, after all that is a point where water ingress may happen(Although it shouldn't since these tdcm motors are completely sealed systems that has bearings on each side). Do you have any photos of the cassette hub assembly and the motor when you take it out?

I'm guessing the 20nm of the axle keeps everything together.

I don't think so. If that was the case then it means axle somehow puts pressure on the tip of the cassette which would prevent the cassette hence wheel from turning in the first place.

Marine grease makes sense since it is good at repelling salty water. Is the grease you use also di-electric? (since you are using it one or near the motor, sensors, connectors I think it is important to use di-electric grease).

 

[Akrotiri]

Has anyone have an issue with ingress of water in Stromer's rear motor hub? I have a 2019 ST1X noticed this issue when my rear wheel started freeze up after a cold overnight in the garage. My garage regularly goes to -15 to -20°C in the dead of winter and I regularly ride in salty/wet/cold conditions. I took the wheel and cassette off to inspect it and noticed little to no grease where the freehub and pawls meets the teeth (possibly water ingress from there?). I thought the motor would be completely sealed.

Dealer was able to warranty a new motor and said the issue could be from condensation from the hot motor windings cooling in a cold garage after a ride. The issue hasn't occurred since (but could be because of the warmer weather now). I made sure to grease the hell out every possible ingress point on new motor. Wonder would this issue come back especially when my warranty expires during a future winter.

Here's a vid and pics:

https://imgur.com/a/AlCQc0r

Very unfortunate but it’s part of the design flaws of hub motors in general. Hubs are more exposed to the elements especially being in the rear wheel with all the snow flying around the rim and saturating the motor. Mid-drives are insulated from this and aren’t affected. One of the many pros of mid-drives over hub motors.

Also seems to be a design flaw that’s allowing water/condensation to ingress inside causing the dead motor. Since it’s a hub It should be completely sealed from the elements but obviously that’s not the case.

I don’t think it’s your fault for leaving it in the garage overnight. Surely stromer has designed their motors to be able to withstand cold temps. And like you said it’s basically no different than keeping it locked outside while you’re at work.

Thankfully your dealer is good and is replacing the motor under warranty as this should not have happened from being caked in snow. However, trying to place the blame partly on you by saying garaging it helped cause this via temperature fluctuations is laughable.

 

[Johnny]

@kmosdell Let me be clear , I am not blaming you for the water ingress, again it is supposed to be water proof. However I want to emphasize that when riding in cold weather and salty/slushy conditions extra care has to be taken. This is true for every bicycle not just ebikes.
That being said it is possible that you simply had a defective motor (How long have you been commuting, was this your first winter ?) moreover Stromer is good on warranty, your new motor comes with a new warranty so you are actually protected for a long time atm.

It is not about storing the bike in cold temperatures, in your garage, it is about letting the bike dry first before doing so. Except the battery, you should always store the battery in room temperature. This is true for every ebike.

@Ravi Kempaiah has ridden his Stromer in winter conditions and he may give you some tips on how to take care of your bike better.
Also you can get in touch with Grin tech who are located in Canada and specialize on hub motors. They look like cool people and have experience with all kinds of hub motors.

When I commuted with my mid drive in under cold, salty and snowy conditions, although I always kept the bike inside and dry after the rides, at the end of the winter I had to rebuild my rear hub and service several other bearings. That is what salt does.

Again, it is not a hub only issue, mid drives also need similar care. In winter you should rinse the salt away and let it dry after commuting to keep your bike running smoothly. Even Bosch states this as a tip for winter riding. (the last part https://www.bosch-ebike.com/en/news/care-of-ebikes/) .

Water ingress in mid drives can happen too, you can find examples for Bosch gen 2, Brose, Yamaha (See these , he actually rebuilt all of them, https://www.youtube.com/user/1200Pete/videos ). Bosch even has released a bearing replacement kit.( Newer generations seem to be improved and better at preventing ingress). I don't know the ip rating for the older Cyro drive on St1x since they don't state it. Maybe they also improved it.

 

[Ravi Kempaiah]

Well, this has happened to every motor manufacturer.
Earlier motors by Yamaha, Bosch, Brose all had some water ingress problems that lead to bearing failures.
In fact, Stromer hu motors are sealed and pretty robust actually. I know of riders who have done over 50,000 kms on the same motor with so issues.

 

[kmosdell]

Well, the new motor is also frozen after it being -10°C overnight in the garage. I did take the new motor through some wet and salty spring weather and greased the hell out of the hub so not sure how the water got in.

Also here's a vid and pic of the hub where the freewheel mechanism just "quick releases" from the motor.

https://imgur.com/a/dnHbDbv

 

[Akrotiri]

B

Well, the new motor is also frozen after it being -10°C overnight in the garage. I did take the new motor through some wet and salty spring weather and greased the hell out of the hub so not sure how the water got in.

Also here's a vid and pic of the hub where the freewheel mechanism just "quick releases" from the motor.

https://imgur.com/a/dnHbDbv

Very unfortunate , but I did day earlier in the thread that it is due to inherent design flaws in Stromers hub motor. Obviously there are people that disagree with me saying that but your first hand experience proves otherwise unfortunately.

I recommend that you immediately take it back to the dealer and demand that they rectify this because it’s unacceptable. An e-bike should be able to handle rain and cold garage temperatures. If they can’t can’t fix the issue perhaps they should give you 100% refund so you can purchase from another e-bike brand that isn’t frail.

 

[Johnny]

Well, the new motor is also frozen after it being -10°C overnight in the garage. I did take the new motor through some wet and salty spring weather and greased the hell out of the hub so not sure how the water got in.

Also here's a vid and pic of the hub where the freewheel mechanism just "quick releases" from the motor.

https://imgur.com/a/dnHbDbv

Just to eliminate, have you checked if the freehub body is working properly? Is your lockring tight? Can you take out the cassette and check, then reinstall the cassette and tighten the lockring to spec?

 

[kmosdell]

Have you checked if the freehub body is working properly? Is your lockring tight? Can you take out the cassette and check, then reinstall the cassette and tighten the lockring to spec?

There is no lockring for the freehub body. Video is basically as-is with wheel off. Cassette lockring doesn't secure onto the axle.
I think freehub is basically held firm with the 20nm on the thru axle.

 

[Johnny]

There is no lockring for the freehub body. Video is basically as-is with wheel off. Cassette lockring doesn't secure onto the axle.
I think freehub is basically held firm with the 20nm on the thru axle.

There is(I was talking about the lock ring on the cassette, that lock ring never secures on an axle anyways), it is the ring at the tip of the cassette that holds cassette and hub body together. I believe it is a 11-42 shimano cassette you have there (m7000 slx if I am not mistaken).

Please see this video for the removal procedure. You will need a lock ring tool.

 

[kmosdell]

-snip-

Yeah that lockring is fully secure with it holding the cassette to the freehub body.

Most QR/thru axle bikes have locknuts holding freehub body to the hub that fits to the drop outs:

Stromer's motor has a nut (so cassette doesn't rub on frame) but doesn't lock the freehub in any way. My point being is that water can ingress into the hub because the freehub body (and cassette) can simply be removed.

 

[kmosdell]

Anyways the shop got back to me saying Stromer diagnosed the old motor stating the seal failed. The shop will diagnose the electrical this time around and possibly put another new motor on. Hopefully this will fix the problem.

I'd say it's probably a design flaw with this Cyro drive.