zachv81

I am in the process of building up a new bike for 50/50 gravel and road usage. I'm torn between Ultegra mechanical and DI2. The frame will accept either groupo. I do not want to compromise reliability as at times we will be very far from any towns, etc. I am a little worried about DI2 with torrential rain, and constant vibration. I have read over and over that this supposedly isn't a problem, but given enough time and frequency of this it will no doubt compromise the DI2. Any thoughts and comments on this?

Andy_K 

I have no experience with Di2, but I've never seen a report of the kind of failure you're worried about. I think your logic is sound and given enough time it's bound to fail in some way. The same is true of the mechanical system.

As I said I haven't used Di2. I have had a mechanical shift cable snap on me when I was out in the middle of nowhere on a gravel road. If I had brought a spare cable and cable cutters I could have fixed it, but I hadn't so I rode 25 miles back to my car in 3-speed mode. I'm not sure what your options are if Di2 fails on you, but I suspect it's similar to having a mechanical system fail when you didn't bring a spare cable.

I suspect that the mechanical system is much more prone to failures but significantly cheaper and easier to repair when it does fail.

profjmb

I chose mechanical on my Trek Boone and wish I'd gone with Di2, which I have on one of my road bikes. It's awesome.

Cyclist0108

You'll be fine with Di2. I got it bundled with my hydraulic brakes (which was the only option at the time). But I am not a bit sorry. It is great. I do a lot of off-road and really beat on it.

Also, it gives you a lot of warning before the battery dies. I let it go too long just out of curiosity. First thing to go is the front shifter, but only after a lot of indication. The only thing I would worry about is a transcontinental tour, but even then you could just bring a charger or have a bike shop do it while you got lunch.

shoota 

Contradictory much? I seriously doubt you will ever be able to compromise di2.