Rail (750Wh) Rail keeps cutting out.

[Geedog]

Hello, has anyone had their 2024 gen4 9.8 rail cut out for a second or 2 on a regular basis, mine has done this from new, mainly on big rides, I only notice it going up of course, I have taken it to my local trek shops 3 or 4 times with the same problem, and they have replaced the battery and some wiring loom, but it still happens.
And also and only occasionally the light on the control panel goes orange, indicating a fault, but the bike still rides as though it's in tour or emtb with no fault.
I have 2 rails, the other is a 2021 9.8 that has been faultless, apart from motors dying, after 3500miles each.
Any info would be great, thanks

 

[Renton_Yorkshire]

Does it cut out under the same conditions, for example if you did the identical route twice, would it cut out at the same place? i.e could it be specific a shock level/vibration thru the frame that's causing it? Also you mention up hill, does it cut out on the flat, smooth path?

Does the system entirely lose power when it cuts out, or is it just power from the motor that stops temporarily?

 

[Geedog]

Does it cut out under the same conditions, for example if you did the identical route twice, would it cut out at the same place? i.e could it be specific a shock level/vibration thru the frame that's causing it? Also you mention up hill, does it cut out on the flat, smooth path?

Does the system entirely lose power when it cuts out, or is it just power from the motor that stops temporarily?

Hello, no it doesn't do it at the same place, but it does happen on rocky climbs more than anywhere else, so could be shock level, it has cut out on not so bumpy trails but that hasn't happened for a few months, since the manager of my local trek shop took it for a ride, and he said it was an overheating battery, since I've had a new battery and wiring.
No lights go out when this happens, just no power for a couple of seconds.

 

[Plummet]

First step. Remove and the battery and clean the terminals with contact cleaner. Slap back together and test.

 

[Shiney2512]

I had the same issue on a 2023 rail 7, ended up being the battery not aligning properly with the bottom plate - Trek installed a new bottom plate and extra padding in the battery compartment (all done under warranty)

 

[Stihldog]

This ^^.
I had the same or similar issue with my Rail. A proper battery realignment helped.

My power cut-out would happen during a specific vibration frequency (usually the same location) which became puzzling. I thought there could be a flux-capacitor buried on the trail

 

[Geedog]

Thanks for the replies.

 

[Dude]

You likely have a RIB alignment issue. I had the same problem on a 2023 Gen 4 9.7. Was in the shop forever because RIB parts were backordered.

Bike would cut out on any bumpy section. The core problem is the battery rattles out of the connector just enough for it to lose contact.

 

[Renton_Yorkshire]

I had the same issue on a 2023 rail 7, ended up being the battery not aligning properly with the bottom plate - Trek installed a new bottom plate and extra padding in the battery compartment (all done under warranty)


View attachment 160172

Interesting, did it not have a springy plate in it, before the foam inserts?

Id get a picture but not near my bike currently.

 

[jgusta]

Hello, has anyone had their 2024 gen4 9.8 rail cut out for a second or 2 on a regular basis, mine has done this from new, mainly on big rides, I only notice it going up of course, I have taken it to my local trek shops 3 or 4 times with the same problem, and they have replaced the battery and some wiring loom, but it still happens.
And also and only occasionally the light on the control panel goes orange, indicating a fault, but the bike still rides as though it's in tour or emtb with no fault.
I have 2 rails, the other is a 2021 9.8 that has been faultless, apart from motors dying, after 3500miles each.
Any info would be great, thanks

Likely due to internal motor mount plate small torx bolts loose and/or snapped off, causing motor slop in frame. Was case for me many, many times on 21’ Rail that is officially dead and not working anymore. Have to drop motor fairly regularly to check for loose or broken bolts. For me, bike shop recommended every 3 months to check. Paid a bunch of money last time due to heli-coiling bolt threads with all new bolts just to have bike as back up bike and it officially died this past year just taking up space in my garage. Two ebikes down, back on analog

 

[Mature ebiker]

Hello, has anyone had their 2024 gen4 9.8 rail cut out for a second or 2 on a regular basis, mine has done this from new, mainly on big rides, I only notice it going up of course, I have taken it to my local trek shops 3 or 4 times with the same problem, and they have replaced the battery and some wiring loom, but it still happens.
And also and only occasionally the light on the control panel goes orange, indicating a fault, but the bike still rides as though it's in tour or emtb with no fault.
I have 2 rails, the other is a 2021 9.8 that has been faultless, apart from motors dying, after 3500miles each.
Any info would be great, thanks

Hi Geedog from NZ,

I own a Trekrail 9.8 2021 gen4 having riding over 6000km without any issues. Just looked at your photo of the battery cavity, my first impression is the male battery contacts are dirty. The battery has a heat sensor which when the contacts get warm will trip out the battery (safety feature). Remember low voltage high current is passing through these contacts. I suggest you clean the contacts to a polished state, check the base of the contact plate screws are tight as this will cause misalignment. Use ENOX to clean the contacts then apply very liberally dielectic grease to the battery contacts also the male contacts. The dielectric grease will keep moisture and dirty out of the contacts. Happy riding.

 

[Geedog]

Hi Geedog from NZ,

I own a Trekrail 9.8 2021 gen4 having riding over 6000km without any issues. Just looked at your photo of the battery cavity, my first impression is the male battery contacts are dirty. The battery has a heat sensor which when the contacts get warm will trip out the battery (safety feature). Remember low voltage high current is passing through these contacts. I suggest you clean the contacts to a polished state, check the base of the contact plate screws are tight as this will cause misalignment. Use ENOX to clean the contacts then apply very liberally dielectic grease to the battery contacts also the male contacts. The dielectric grease will keep moisture and dirty out of the contacts. Happy riding.

Hello, mature biker, thanks for the advice, I shall do that, though the bike in the picture is not mine. I too have 2021 9.8 that has been brilliant, with at least 12k miles, and on 4rd motor though. And I love the 2024 model, it rides superbly imo, just a bummer it keeps cutting out, would like it sorted before the warranty runs out though.