9.8XT keeps cutting out… no error messages

[Mr_Price]

So I’m pretty sure this is a connection issue but it’s really weird. Cut out twice today on very easy FLAT trail. It was fine for the rest of the 16km / 700m ride which includes so steep climbs and some 3-4’ drops, jumps etc.

This bike has been at the LBS more times than an Alfa. Mostly because of this issue. Around 3 months ago they finally told me a clip was broken in the lock so they replaced it under warranty and it worked beautifully for another 100-120km, no cut outs.

Had a short ride on Friday (after the LBS had it). No issues. Today, I had one power cut out, all dials / meters to zero, assistance cuts out but restarts c.15-20 seconds in. And then a full power shut down.

I feel like I could fix it myself by being aggressive with some tape / foam or something - assuming it’s the battery sliding around - but I’m almost out of warranty and wanted to make sure the LBS put the time in to fix it.

Anyone else had this or got some tips. My buddy has a cube and he had something similar happen.
Cheers!

 

[MOTO13]

My 2020 Trek Rail 9.7 does the same thing. Simply stops working...sometimes the display stays on and the drive simply stops and then starts up a few seconds later. Or, the display also goes out and you have to turn it back on the make the system operate again. The dealer has looked at everything several times with no solution. They are getting contact with Trek and Bosch to figure mine out.

 

[Mr_Price]

My 2020 Trek Rail 9.7 does the same thing. Simply stops working...sometimes the display stays on and the drive simply stops and then starts up a few seconds later. Or, the display also goes out and you have to turn it back on the make the system operate again. The dealer has looked at everything several times with no solution. They are getting contact with Trek and Bosch to figure mine out.

Interesting. I'm quite sure it's a result of the battery sliding up and down. Super tempted to do the 'no key mod,' I ride year round and a few weeks ago my garage was -5ºC, it rarely gets above 10ºC in the winter so I have been bringing the battery inside with me.

If anyone has suggestions to test my loose battery connection let them fly! Maybe some foam at the top of the battery tube?

 

[MOTO13]

That foam trick might be a good idea. I am letting Trek and Bosch figure it out with mine. I have a feeling it has to be in the battery area as well but just don't want to screw with hacking it. I have a Niner with the Bosch motor. I have like 50 miles on it so far with zero issues. So, this leads me to believe it has less to do with Bosch and more to do with the way Trek engineered the battery area.

 

[Doomanic]

Check the connection on the bike. I had a similar problem and it transpired that the spades on the connector had grooves worn in them from the battery rattle.

 

[Mr_Price]

Cheers, will take a deeper look.

 

[Stihldog]

My Rail 9.7 2020 did this on flat rocky roads. Usually in the same area too…weird.
So a possible fix is the bottom bracket in the battery area. (Where the battery makes connection). I read and then tried to adjust and move this bracket slightly. The two small screws at the bottom of the frame will allow this. It won’t move much but it may be enough to stop a loose connection between the battery and the bracket. Might be worth a try?
Mine is better now but not completely. Only happens once every 5 rides now.

 

[Mr_Price]

It used to happen so consistently on one part of the trail that I was convinced there was some sort of magnetic inference. Happens to be an old military training area.

 

[Orangie]

If you connector looks like this , Replace it

 

[Stihldog]

If you connector looks like this , Replace it

View attachment 80818

Now if you could just add some conspiracy story along with your pic, this could be more believable. (ie; riding past a magnet factory).
That does look bad though.

 

[Orangie]

Battery wears away contacts. Then bike shuts down over rough terrain

 

[dixie600mhz]

I get a cut out with an error '603' quite often. I don't think mine is vibration related. I'm waiting on the LBS getting back to me with what Bosch advise. Hopeing I don't have to drop the bike off. I ride 4+ times a week.

 

[Stihldog]

I think @Orangie ’s description is the most plausible for this vibration-cutout-issue. The battery rattling is probably adding to the premature wear of the connections.

 

[MOTO13]

My 9.7 has done this from new. The battery connections theoretically shouldn't have been worn at all. Not only that, but my bike (battery area) literally has no rattle what so ever.

 

[Stihldog]

I wonder if there’s enough movement there to cause some wear without hearing any battery-rattle? Maybe the difference in lock adjustment could stop the noisy battery rattling while still having some movement at the connection point. I’m just spit-balling here. Maybe some foam? More foam?

 

[markloch]

I wonder if there’s enough movement there to cause some wear without hearing any battery-rattle? Maybe the difference in lock adjustment could stop the noisy battery rattling while still having some movement at the connection point. I’m just spit-balling here. Maybe some foam? More foam?

i had same issue on bumpy descents. Trek shop tech showed me a trick: take off motor shield, loose the bolts on the underside of the downtube that fix the bottom battery bracket, take a long handled hex wrench and position it carefully past the motor onto the backside of the bottom battery bracket, press the bracket into the battery, tighten the bolts. Test Battery removal as pressing too hard can make battery removal difficult. What was a once or twice per ride event hasn’t happened since, many dozens of rides. I found this was all easiest to do with the bike flipped over onto seat handlebars (resting on scrap 2x4 to protect levers etc) rather than on a bike stand.

 

[Mr_Price]

How much crap do you find inside your battery seal after a ride? Just wondering if this some how shows the battery is moving around too much (letting dirt in) and causing the cut outs?

 

[Stihldog]

Just wondering if this some how shows the battery is moving around too much (letting dirt in) and causing the cut outs?

Hmmm? My battery looks the same when I remove it every 3rd or 5th ride. There’s usually no debris or water at the electrical connections either.
It seems there’s not a perfect seal in the battery compartment area but as long as I stopped hearing the battery rattling (pieces of foam) a loose or worn out electrical connection could be the culprit.
I haven’t had my battery pop out on the trail but my neighbor has…once, but he doesn’t have the cutout issue I sometimes get. I usually peddle through the assistant cutoff which only lasts for 5-20 seconds, but it’s on a relatively flat and bumpy section of access road. And what’s weird is that it’s usually the same stretch of bumpy road. (Super natural forces in effect here.) (I’m having some crazy theories ).

 

[Mr_Price]

And what’s weird is that it’s usually the same stretch of bumpy road. (Super natural forces in effect here.) (I’m having some crazy theories ).

I have a bit of theory on this: has the battery now “warmed up” - would it swell slightly, or even contract? - either way, did this change in state cause the battery enough movement to cut out?

Next week I plan to take a battery from another bike out to eliminate there being a battery issue.

FYI there is never dirt or debris by the contacts.

 

[Stihldog]

I have a bit of theory on this: has the battery now “warmed up” - would it swell slightly, or even contract?
Next week I plan to take a battery from another bike out to eliminate there being a battery…

Battery expansion. I’d think the battery wouldn’t last too long. Minute expansion and contraction is possible but that could be engineered into the design. As suggested, it’s probably the “knives” of the electrical connections.
I have a couple of 550w batteries I could try. Might try that.