Shimano Di2 Derailleur Failure Part 2

Jim’s Tech Talk

By Jim Langley

So far 37 comments have dropped on last week’s story about replacing an old worn-out Shimano Di2 electric shifting front derailleur. I closed the article asking for your thoughts on e-shifting and you delivered! Thank you. 

If you missed the story, catch up here: Thoughts on Wearing Out my Shimano Di2 Front Derailleur. Be sure to continue to the comments section below the feature because there’s a lot of interesting and helpful feedback. If you’re considering a new rig with electric shifting but haven’t made up your mind, I bet some of the input will sway you one way or the other.

Since last week, there have been requests to see the insides of the Di2 derailleur. So, I dissected it more and made this teardown video that shows the nylon worm gear – the part that Shimano said wore out:

My Final Wishy-Washy Thoughts on E-Shifting

Seeing the small part that failed on a front derailleur that was otherwise perfectly ready to shift for years more was frustrating. I had the same feeling when I had to abandon my once revolutionary Mac Air laptop simply because Apple stopped supporting it.

Those are real issues with electronic devices and software. New stuff isn’t always compatible with the old version and companies can decide to head in a completely different tech direction at almost any time.

Personally, I enjoy and prefer fixing the things I’ve already got. I also want to be able to do it myself and even when I’m on rides. I’m not sure electronics will ever be that repairable or foolproof. The issue of dead batteries alone seems like playing Russian Roulette. And yeah, it’s easy to charge but it’s even easier to forget to charge.

And speaking of batteries, how many times has the technology changed already? Just when you think you have the best, it’s replaced with something that doesn’t play well with what you have. I get it that we all want better batteries and benefit from them, too. But, I don’t like having to continually upgrade parts and I worry about all those batteries being discarded.

Still, it was easy to replace the broken Di2 derailleur and my e-shifting is working like a champ again. And my new Mac mini M1 is an incredible upgrade from that Air. So part of me is open to the idea of another electric shifting bike and I would definitely want wireless.

Your Feedback to the 5 Questions

That’s enough from me. I enjoyed reading all your comments. What I’ve done below is go through them and come up with a consensus on 5 of the questions I asked last week.

In favor of or against electric shifting?

Interestingly, there were thumbs up and thumbs down from those who own electric shifting, not just those who don’t. Overall – those in favor of electric shifting edged out those against.

How long should electric shifters last?

“5 years” Wm Wiesand

“I would be happy with the lifespan you got out of your FD” Johan

Overall here, the consensus was that front derailleurs wear out if you ride enough and that mine lasted long enough.

Do you think electric shifters are overpriced?

By far most of you said yes.

Should they be repairable?

Reading in between the lines, I get the feeling most of you would like to be able to repair your components, even the electric ones.

Have you had one fail and what broke?

Di2 front derailleur failure: spring popped out and had to be replaced

Di2 failure: the lever failed inside and had to be replaced

Di2 front derailleur failure: linkage arm broke but was easy to replace

Di2 front derailleur failure: same as mine

Di2 rear derailleur failure: needed a software upgrade

Di2 failure: the lever failed inside and had to be replaced

Wow, that’s more than I expected. While several riders use SRAM and Campagnolo e-shifting, no one reported failures with those.

Unexpected Feedback

Here’s a selection of my favorite quotes from your comments.

Alex Pline wrote, “All of the “tennis elbow” I attributed to using the right mechanical shifter went away very quickly when I installed the Di2.”

RAH said, “Be wary of wireless shifting systems. or of considering it. as a feature.. Wireless systems are easier for equipment installers, but they have less operational reliability. The frequencies used for wireless communication are shared by a wide range of other types of users – including equipment used by the bicyclists themselves, and there WILL be interference problems – guaranteed. Many times interference symptoms will be unexplainable, erratic, and unreproducible.. There are ways to engineer products that can minimize such occurrences, but the cost of equipment will measurably increase, and battery life will be measurably degraded.”

Ostrinsky Lloyd pondered, “Am I going back to mechanical? No. But I might change when someone comes up with mind control shifting and braking.”

Bigborb opined, “All the current transmission systems for bicycles still have all working parts hanging out from the bike and exposed to the elements – water, dirt, etc. I am waiting for someone to come up with a practical solution to this obvious flaw. Surely a sealed system with low friction and maybe even a sort of ‘constant velocity’ transmission can be devised for bicycles..? Meanwhile, I am happy making my mechanical adjustments on something I can actually see and feel while riding the bike.”

Johan pointed out, “One area where wireless electrical shifting shines is on BreakAway / S&S coupled bikes for plane travel. Two fewer cables to connect and disconnect is a plus!”

Al Bet advised, “Advances in electronics and tech make things obsolete. Such will be the case with DI2, which just gets better and better. Price? Expensive but like a new cell phone-worth it.”

Bryan explained, “With the Shimano system the two small shifters on each lever are so close that it makes it easy to hit the wrong one and have the bike shift to the wrong gear. This is worse when I get tired or in the midst of a tough race. I haven’t tried Campy electric, but it just makes more sense having the shifters in different locations on the levers so you can’t make that mistake.”

Richard Paul Handler suggested, “Try the current Shimano 105 mechanical and you’ll not miss Ultegra or Dura-Ace. Replace worn parts with 105 and save money.”

Peter Wimberg stated, “I have eight bikes and just one with Di2. All of my other bikes have cable shifting. I don’t plan on changing over to all electronic shifting. I think being forced in that direction by the component manufacturers would be a mistake on their part. We tend to want to make something so simple like the bike more and more complicated.

Bill Bagnell penned, “I’ve owned two bikes with Ultegra Di2. I wouldn’t have anything else. I never think about shifting now, it’s so easy that my fingers seem to flick the buttons without conscious thought, with the result that I shift all the time, on every slight change of grade or wind.”

Campagnolo E-Shifting

I’m wrapping this up by answering a good question from RAH. He asked, “The article seems to leave Campagnolo and EPS out of the discussion. Since SRAM is also mentioned, was this intentional? Is Campagnolo going out of business?”

I explained that the only reason I didn’t mention Campagnolo EPS is because I have not used it or worked on it. I also don’t ride with anyone who uses it and the only time I’ve seen it in the “wild” is at bicycle shows in Campy’s booth. Since I don’t have any. real experience with it, I didn’t mention it, but they are still Campagnolo, perhaps the most loved component brand of all time and I’ve heard EPS is an excellent system.

To which, Mark Dehanke helpfully chimed in, “I have Campagnolo EPS V3 on my Colnago C64. I have nearly 7,000 miles of usage with this system, and am quite pleased with the performance and dependability/durability of the system.

The shifting of the front derailleur very much impresses me with the speed, efficiency, and EASE of the shift process. The rear shifting is a step above the mechanical; due to the ability to do all the multi-cog shifts with just the push and hold of a button. Granted, one can hold down the mechanical lever with ultra-shift and move 3-4 cogs, but you can move 10 cogs at a time with the EPS!

In closing the EPS rear shifting is good; but, the FRONT is FANTASTIC!!”

Thanks, Mark and thanks everyone else who commented!

10,116 Daily Rides in a Row

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Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s cycling streak ended in February 2022 with a total of 10,269 consecutive daily rides (28 years, 1 month and 11 days of never missing a ride). Click to read Jim’s full bio.