55tele

How "robust" are these? I have a new bike with Ultegra Di2 and I guess when putting into the SUV to take home, I must have pressed the downshift button and it tried to move the cage in....didn't see it until I got it home about an hour away....I turned the crank to complete the shift and tested after and all seems well....I don't want to make a habit of doing this, but are these things engineered to survive an occasional mistake like this?

Iride01 

I've done similar a few times. Perhaps one of us will find out one day how robust they are.

So far the only issue is for me is that sometimes I'll drop a chain immediately when starting out. I think it's when I rotate the crank backwards a little to get the pedal in the correct position to clip in and pedal.

Steve B.

Never lay the bike down on the drivetrain side. Also make sure nothing will be pushing on the short levers.

Cyclist0108

I haven't had a problem since I got it in 2014, and I use it off-road a lot, and fall frequently enough that I have implicitly tested its robustness.

TimH had one break in a way that a few others reported, so I think they do have a weak point. Thread is around here somewhere. I am fairly sure that in his case it was caused by oval chainrings.

jadocs

I was going to say the same thing until I thought about it....the front derailleur is controlled by the non-drive side shifter.

cxwrench

I've seen 2 front derailleurs that broke at the linkage. Both bikes were floor bikes at the shop. Shimano said it happens when people shift them when they are not being pedaled. The 'Oh cool...there's electronic shifting now? Lemme try it' thing.

55tele

Yes, I understand not to lay the bike down on the drive side....this happened from laying the bike down on the non drive side and the left lever somehow getting pushed, probably by me getting it in the back of the car. I had the front in the big ring. I know NOW to shift into the small ring up front before transport so if the lever does somehow get pushed, it won't do anything. I personally wish there was a "sleep" or "standby" mode so you couldn't inadvertently shift it...

Riveting

If their front der. shifted, then the bike wasn't laying down on the drive side, since the front der. shifter is on the non-drive side. -Sherlock Holmes

Riveting

Don't worry, I've done this 100's of times on my Di2, usually when positioning the bike near others and the shifter button gets bumped. If Shimano didn't account for this, it might have been the worst engineering oversight ever, just behind the Ford Pinto.

55tele

Awesome! My wife had a Pinto.....typical Ford POS....

veganbikes

It is pretty robust so I wouldn't worry a huge ton but I would potentially if possible if you aren't doing it super duper often is have a TL-EW02 which is the wire installation and removal tool and just release the wire from the derailleur if you are super worried about it. Though really I would be careful about the shifter getting impacted but truthfully I would get a hitch and install a rack in it (and yes your car most likely can have a hitch, we have installed into Tesla sedans, Ford Mustangs and other smaller cars as well as various SUVs and Wagons) and that way you can carry your bike properly with no worries about shifting.

55tele

I looked at doing the hitch and bike rack thing.....I don't want the receiver on my car and the racks I'd trust are too expensive. I actually bought my car (Toyota Highlander) so I could get the whole bike in the car without removing a wheel and I have the technique (aside from the inadvertent shifter button pushing) down to get it in and out....

I also don't like transporting bikes outside for theft and weather potential.....

Used a Thule roof rack many years.....it was OK...My favorite setup was fork mount in a minivan.....bike was secure from theft and protected from weather, but I didn't want another minivan....

I think just making sure I'm in the small ring should prevent the issue....I made it from Denver to Chicago over the weekend with no issues transporting this way...