Cyclist0108

I've had a bike equipped with Ultegra Di2 since 2014, and it has been flawless.

My son has had a 2020 Trek Emonda with Di2 Ultegra, and it has been problematic from the beginning. Briefly, it occasionally loses all charge. What is frustrating is that two of the most recent incidents happened on race days. Thankfully he had a backup bike with him, but this is extremely frustrating.

The dealer (formally Bike Gallery of Portland, OR, now directly owned by Trek) replaced the battery on warranty, but the problem persisted. A couple of weeks ago he brought the bike in for a full diagnostic. They updated the firmware for him and said the diagnostics indicated no problems.

I was present for both of these races. In the case of yesterday's race, I kept the bike in my hotel room, and verified it was fully charged using my own Di2 charger (just in case his had a fault). At 5am it was fully charged and he left for the race. At 8am he checked and most of the charge had gone. After 3 shifts it failed completely. So I am reasonably confident this isn't a case of user error.

He now wishes he hadn't taken my advice and had got the mechanical shifters. I popped for Di2 based on my flawless experiences (and those of many others), and thought I was doing him a favor, so I feel a bit responsible for this, too.

I'm kind of at a loss what to do about this. Any advice? Anyone have any similar experiences? I'm hoping it is something as simple as a loose cable, but I can't find it, and I don't understand how a battery could drain that quickly unless one of the shift buttons was stuck (it wasn't).

The only way to reliably reproduce this is to enter into a bike race.

Troul 

Find the short in the wiring. Likely pinched or skinned & prematurely draining the battery.
is the battery getting unusually warm?

Kimmo 

I'd pull off the bars and get the rest of the stuff off the bike, and look at it on the bench.

If you can't see anything wrong, leave it till it goes flat (or you could just skip that bit), remove a component and repeat. Wait for it to go flat, remove another component, repeat, etc.

Iride01 

It's still electricity. You can check for shorts and leakages with a multimeter if you know how.

Though this is still new enough to possibly involve items still under warranty isn't it? I wouldn't muck around with it and void my warranty until I exhausted the patience of the dealer and maybe a few other authorized Shimano reps.

jnbrown

Are you sure it is loosing charge or just a loose connection?
My wife's Cannondale had a problem where the shifting would stop working intermittently.
I finally accessed the junction box in the BB and reseated all the connectors and the problem went away.
Took months to figure out.

Cyclist0108

The problem is I am now 700 miles away, and I was hoping the bike shop would Do the Right Thing. (I could have brought it home with me yesterday, but then I would have 1400 miles of driving to do to get it back to him, assuming I could even fix it. The kid doesn't have many tools or mechanic skills -- he is reliant upon the Trek dealership to make it right.)

Cyclist0108

Yes, Shimano's warranty on this is for two years (3 for Dura Ace/XTR). In this case I can't muck around because I live so far away.

Cyclist0108

Thanks. I agree with the diagnosis. The battery is inside the seat tube, so I have no idea if it is getting hot. I suspect it is NOT the battery since they warrantied it and it is still doing the same thing, but a short could be toasting the battery.

Steve B.

Possibility of faulty cable. I'd want the shop to swap all cable. Doing that also checks that all are seated correctly.

Cyclist0108

I'm not sure, and I am hoping the bike shop would try this (given that they or Trek assembled it).

Troul 

looks like he's stuck between a rock & a hard place, if leveraging the warranty is the expectation. We can't tell or provide a shop with how to do something, especially when it's not our repair order to be addressed.

Let us know what the problem ends up being & how long the servicing took. I'm thinking harness or rear der & three hours of service. They won't own up to it though.. "Another bad battery"

Cyclist0108

The one card I have to play is the receipt is in my name (and I've been a Trek customer since the early 1980s, not that anyone would care at this point).

Troul 

That may pose an issue for your son if they try to press on a shop to fix it once & for all. In my opinion, a loyal customer means as much as a single bottle deposit to the average business person.
It will come down to interacting with the a certain zodiac on their best day while having good internal networking, in order to have the issue [timely] resolved.

Cyclist0108

Fortunately, he has the same name.

Troul 

Jr. might have better odd with the younger tone.
Mondays are not typically best for customer service needs.

Cyclist0108

I think he is too under-assertive, but I hear you and will wait until Tuesday.

I almost drove an extra 150 miles each way so I could have a tantrum at the bike shop in person after the race, but Jr. is more level-headed and talked me out of it.

He managed to ride an old sluggish heavy aluminum Diamondback and still did comparatively well.

TiHabanero

Thankfully your son prevailed and talked you out of shooting six guns at the service guys. Not a nice way to do business regardless of the circumstance. Just start with the basics, connections seated, wiring in good condition, wire routes cleanly through frame etc. It is just electrical current and is very logical to work with, however I will admit I am not a fan of it.

Cyclist0108

I was being a bit facetious about having a tantrum, but I wasn't about going to the shop after the race. The problem is that Di2 works so well in the vast majority of cases that it is easy to be dismissive of subtle problems that can't be easily demonstrated. I totally understand that, and the reason why I kept the bike in my own control in the hotel room the night before, and on my own charger, is so I could convince myself that it wasn't some sort of user-error. Also, I am not sure the kid explained the problem as well as I could, half of which involves convincing them you haven't just done something stupid (especially as it is a possibility, but having two people do it without knowing it lessens that chance).

(By the way, I got it for myself because hydraulic brakes were at first bundled only with Di2, and I really wanted hydraulic brakes after a severe injury. It turned out I liked it far more that I could have imagined, and have since become an evangelist.)

Cyclist0108

Well, I sent off a politely-worded email. Hopefully this gets resolved. My kid wants to know how much it would cost to upgrade to mechanical shifting.

Cyclist0108

No reply. Should have gone with the in-person tantrum.

squirtdad

this would be good time for him to learn mechanics, but this is not the optimal way, lot depends on if the frame is ready for both di2 and mechanical shifting. Front and rear derailers, and brake/shift levers to match the breaks for parts

Cyclist0108

Finally heard back. They want to Do the Right Thing. So, hopefully it will be straightforward.