Rail (750Wh) Multiple power offs today and not delivering correct power when turned back on

Dave_B

Dave_B

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It was wet today, the bike started to turn itself off, got to a point where it would only stay on for about 30 seconds and when on, it wasn’t delivering power…..it’s back at the shop, hopefully fixed ready for next weekend….

Anyone else had this?
 
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Not a 750w battery but I experienced the off/on from vibrations (gravel road). Same location too. I’ve never had an issue with water ingress. Maybe I’m lucky but my relationship with water while riding is deep and often. 🙄.

My fix was simply the battery to connector contacts. Readjusted the battery alignment and slightly adjusted for better contact. The short wiring harness seemed okay. I also use a non-conductive grease at the motor connectors (3-4?).
 
Yeah I thought battery, but it was at its worst at the end of the first loop on smooth roads.
 
Yah, sounds like a weird issue, or a mystery.
I just re-read @Bearing Man ’s post on motors. He may have experienced or seen this problem before and could have a suggestion. I don’t have any electrical issues at this time …(thank goodness) but I’m gonna take his advice on some preventative maintenance or servicing for the Bosch gen4 motor.
 
I think @Dave_B 's is quite tight as he's running with a bent bottom plate ? Maybe with Arron's Brokeback Mounting it will be tighter still.

On the bright side, at least you have this now and not with the new mount, as logic would dictate that as the cause.

There seem to have been a few similar issues lately fixed with the latest firmware update, but that doesn't mean that's the solution in this case, you still can't help but think it's a connection issue as @Stihldog's implied.
 
It does seem like the Brokeback Mounting system (keyless) could make the battery area a little tighter, or at least less vibration-prone.
 
It repeatedly turned off while going very slowly on tarmac. The ride to that point was mainly manicured trails, so not a huge amount of vibration. Certainly done tougher rides without the issue. The main difference today was that it was wetter than a mermaids snatch.
 
Hmmm. Can’t see how water would affect loss of assist …unless moisture is getting in the computer display? Or controller? …which could cause a number of false issues. Does this only happen when it gets wet?
 
I don’t know yet. Yesterday was my first wet ride.
 
It’s definitely frustrating. When I had my off/on issues with the power assist I could usually ride/power through it until the assist returned. Sometimes the computer screen would completely go blank and not return (twice), but usually I would just lose assist power and peddle through it until power returned.

This loss of assist (or computer display) would never happen on the tarmac (paved roads), or rock gardens, or climbing marbles and large rocks, or any type of decent, …it would only happen on a specific stretch of fire road …every friggen time. I started to believe that it was the vibration tempo on that particular stretch of road (80m) or there’s a Flux Capacitor buried in my path that only affects my bike. Wtf!

Now LBS’s mechanics have seen a lot things …period. But most of them are not that familiar with a relatively new eMTB system. It’s not rocket surgery and their probably not electronic technicians. “Intermittent” translation; I can’t find the problem yet and this could take a while, or this is a mystery. I’ve used this jargon until my bosses eventually got tired of hearing that the problem was “intermittent”.

But hey, maybe it’s a firmware update??
 
If you have the kiox 300 fitted, try removing it, then power the bike on without it and ride without it, see if it still does it.
The bike can be ridden without it, but if it's attached and has a bad connection the bike switches off.
 
My trek wouldn't provide power after my LBS performed a service. The Kiox would light up, but I couldn't get any power assist. Found the Kiox was not completely seated. Took it off and reinstalled it. Worked fine.
 
BobMtnBkr said:
My trek wouldn't provide power after my LBS performed a service. The Kiox would light up, but I couldn't get any power assist. Found the Kiox was not completely seated. Took it off and reinstalled it. Worked fine.
Click to expand...
I found a similar issue once. Kiox lit up but no power assist. My holder is mounted to the top tube (close to the Knock Block stem ring) and is tethered to prevent accidental loss. The Kiox was not seated correctly in the holder because the tether had prevented a proper seat on one corner. It looked fine …but it wasn’t. Easy fix.
 
It's likely the damper pad imo. Had the same issue, removed the pad and haven't had an issue since.
 
Stihldog said:
My fix was simply the battery to connector contacts. Readjusted the battery alignment and slightly adjusted for better contact. The short wiring harness seemed okay. I also use a non-conductive grease at the motor connectors (3-4?).
Click to expand...

THIS^^^ worked for me . Applied dielectric grease to the connectors between the battery and motor and tightened the battery with a few pieces of dense rubber. I went from having shutdowns every other ride to none since applying the grease. Its been four months and I ride about three days a week in a rough rocky area. Bike is a Yamaha ydx, the fix was recommended by Yamaha.
 
Similar experience recently with a Giant Trance X Advanced E+2, randomly turning off on rough or smooth terrain, eventually dying completely. Bike had done around 800 miles.

LBS (the excellent Cycle World Portsmouth) had 2 attempts at fixing, eventually concluded it was a battery management system (BMS) fault, and replaced the battery under warranty. Have ridden about 100 miles since, with no issues.

The old battery is awaiting the next visit of the Giant rep to diagnose the exact issue, it seems the LBS’s diagnostic kit can’t interrogate the BMS, even though they are a Giant/Liv main dealer.

My mate with an identical bike has just had the same issue, at around 1k miles. His bike is still with the LBS.
 
Mitchb said:
THIS^^^ worked for me . Applied dielectric grease to the connectors between the battery and motor and tightened the battery with a few pieces of dense rubber. I went from having shutdowns every other ride to none since applying the grease. Its been four months and I ride about three days a week in a rough rocky area. Bike is a Yamaha ydx, the fix was recommended by Yamaha.
Click to expand...
I think vibration is your enemy here and it seems like you addressed that by adding a few pieces of dense rubber to the battery area. Also by adjusting the main power connector you’ve likely prevented a loose electrical connections. Dialectic grease only prevents moisture or corrosion from developing if applied correctly.

I can remember slopping dielectric grease around battery terminals and spark plugs (silicone dioxide properties) to prevent water ingress. If used correctly it can be very effective. F570D77C-9A19-4221-B712-B5AE41F1871D.jpeg
It is a terrible lubricant for bearings or metal to metal contact. (Not petroleum based). I use it to repel water only.
 
Stihldog said:
I think vibration is your enemy here and it seems like you addressed that by adding a few pieces of dense rubber to the battery area. Also by adjusting the main power connector you’ve likely prevented a loose electrical connections. Dialectic grease only prevents moisture or corrosion from developing if applied correctly.

I can remember slopping dielectric grease around battery terminals and spark plugs (silicone dioxide properties) to prevent water ingress. If used correctly it can be very effective. View attachment 101313
It is a terrible lubricant for bearings or metal to metal contact. (Not petroleum based). I use it to repel water only.
Click to expand...
Not sure why you would doubt the recommendation from a company with Yamahas' reputation. I tried the dense rubber pads first before getting the dielectric grease recommendation.
The rubber helped but I still had frequent shutdowns.

An engineer friend of mine explained that dielectric grease does more than repelling moisture. It also prevents carbon build up between moving "dry" connector prongs, and that carbon buildup can cause the shutdowns. I think he's correct because prior to trying the grease I could clean the connectors with parts cleaner and get a ride without shutdowns. However I couldnt get two rides due to the carbon build up.
 
Mitchb said:
Not sure why you would doubt the recommendation from a company with Yamahas' reputation. I tried the dense rubber pads first before getting the dielectric grease recommendation.
The rubber helped but I still had frequent shutdowns.

An engineer friend of mine explained that dielectric grease does more than repelling moisture. It also prevents carbon build up between moving "dry" connector prongs, and that carbon buildup can cause the shutdowns. I think he's correct because prior to trying the grease I could clean the connectors with parts cleaner and get a ride without shutdowns. However I couldnt get two rides due to the carbon build up.
Click to expand...
I agree. A poor electrical connections can be problematic. My experience with EBIKE’s is extremely minimal when compared to the engineers at Yamaha. But I know what worked for me. When used correctly dialectic grease can be very useful.
 
Dave_B said:
It was wet today, the bike started to turn itself off, got to a point where it would only stay on for about 30 seconds and when on, it wasn’t delivering power…..it’s back at the shop, hopefully fixed ready for next weekend….

Anyone else had this?
Click to expand...
Yep, 1.5 years of on/off power shorts on 21’ Rail (625). Several fix attempts by Trek..first…battery realignment (no change). Next…battery alignment mountain bracket change (no change). Next…new front triangle due to potential frame improper alignment causing shorts and new Bosch drive unit (better, but problem eventually returned). Solution for time being was not one, but two high tension straps to upper and lower portion of battery to minimize any jostling to connections at all during riding. This helps the most for me.. since then, bike has still numerous weeks and time at shop due to snapped or loose internal motor mounting bracket, galled out rear triangle (replaced). Now at shop over past 3 weeks with new head unit from recent error and complete power cut off that left me 8 miles from car at bottom of trail. Trek shop just called last night and new head unit didn’t fix problem since electronic wires are crushed and motor mounting bracket is all galled out. So, will be 4th drive unit in just over 1.5 years with same problem repeating itself likely until warranty up in 4 months and I am completely hosed. I wouldn’t care as much, if bike didn’t sit in the shop for weeks at a time/every incident. I was hopeful that the new Bosch “Smart” system would correct these power cut out issues, but if you are having them on your 750, that doesn’t sound good and like Trek and Bosch don’t have a permanent solution. Sorry you are experiencing this, has been a long haul of let downs for me, mostly cause I love riding the bike and bike fits me like a glove and suits my riding style and terrain great…when working
 
We think my issue is battery connection. So foam plate pad removed, battery plates re aligned.

Also had firmware updated to battery and motor. Also had SpeedBox removed to eliminate that as a potential source (don’t think it is but it didn’t let the firmware upgrade with it in place so it got removed).

Hopefully the new keyless battery plate with sort out the battery movement issues and stop this power cutting issue.
 
Yeah, think that is where bulk of power off issues lie. All with the battery connection and wiring to motor. Constant battle here
 
I have the older Bosch with the new Neon display. I have experienced similar issues recently (nothing working reliably and powering off) and found it to be some dirt on the display connections. A quick wipe of the contacts on the display and mount fixed it. Took a while to diagnose though !
 
I had an annoying intermittent fault with losing power, shutting down, (2020 Rail 625 )
went back to shop for battery alignment procedure, ok for a while then it started happening again on rough trails!
Tried the securing strap method, to some success, then when bike was out of warranty, i thought, i dig abit deeper, so started by pulling the battery out and i noticed the plug connector from the motor was slightly wobbly, so i pulled the motor out and tried to secure the plug from moving about, finally i put a tiny self tapper screw down the side of the plug body and the plastic mounting, built it back up and Hey Presto !! Not one single power outage/cut out/surge.!!
So if the bottom connector where the battery sits onto is loose , highly likely thats the issue,
Conclusion= the bottom connector from the motor to the battery NEEDS to be improved, at the design stage !!!
 
My issue has returned, but is now more consistent, ie, the bike won’t turn on.

When I power up, the lights on the remote scroll down, up down, the KIOX comes on, but then everything dies.

We thought we had fixed the issue with a new lower battery plate (which has a can bus module on it). I did a 25 mile ride with no issues.

Washed the bike today, it’s now a brick.

Odd thing is, after washing it, it turned in fine.

I’ve just fitted the lock delete bracket, I had to remove the tail plate so was messing with the lower battery plate again, I did test the bike turned on before I completed the install and it was fine.

Finished the install, tried to turn it on and it’s a brick.

Will be taking it back to LBS to see what they can diagnose, when they initially diagnosed it, the error trace could not reach the motor, it went through remote, to KIOX and then errored.

I’m sure it’s moisture related.
 
Dave_B said:
My issue has returned, but is now more consistent, ie, the bike won’t turn on.

When I power up, the lights on the remote scroll down, up down, the KIOX comes on, but then everything dies.

We thought we had fixed the issue with a new lower battery plate (which has a can bus module on it). I did a 25 mile ride with no issues.

Washed the bike today, it’s now a brick.

Odd thing is, after washing it, it turned in fine.

I’ve just fitted the lock delete bracket, I had to remove the tail plate so was messing with the lower battery plate again, I did test the bike turned on before I completed the install and it was fine.

Finished the install, tried to turn it on and it’s a brick.

Will be taking it back to LBS to see what they can diagnose, when they initially diagnosed it, the error trace could not reach the motor, it went through remote, to KIOX and then errored.

I’m sure it’s moisture related.
Click to expand...
Possibly a wiring/electronic issue?

My Rail has been in LBS (Trek store) for 5 weeks now. I had same thing happen with with full power cut off at the head unit about half way into ride. Unfortunately for me it was after the long descent so had to pedal/hoof it back at 2,000ft of steep climbing with no power. When power cut off in past, head unit would eventually come back on, just repeated cut out in ride until resolved.

Bike went to shop immediately after and they said head unit bad and ordered me a new one. Following inspection of bike, they found that most all the wires were crushed from motor to the lower plate and the motor mounting bracket plate loose with threads galled out.

So, I currently await for a new complete Rail from Trek and new drive unit with thicker mounting bracket from Bosch once arrives. Pretty stoked on their “resolution” especially since I have been dealing with these power cut out issues not long after getting the bike that was never fully resolved.

So, my issue lies with the thin motor mounting bracket that would frequently rattle loose, snap torx bolt heads off and likely yanked on/compromised the wiring from motor to lower battery plate.

Fun bike to ride, miss mine with 5 weeks without now, but spends too much time down, at least 8 weeks/year it seems. Hopefully Trek can work these bugs out ultimately.
 
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