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.
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.”
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
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.
Chris VandenBossche says
I have been using SRAM etap for two years now and have had no issues with wifi interference; likewise no problems resulting from water, snow, mud etc. These systems are solid. They are a luxury, but for someone who rides a lot they may be worth it. A few minor pluses: shifting in the winter when wearing heavy gloves is much easier, it’s pretty much set it and forget it (no adjustments with cable stretch etc.), you’re more likely to shift front chain rings (think of the difference between STIs and downtime shifters).
JOHN A JAUSS says
I think you hit the nail on the head when you said the worm gear didn’t look worn out. My take is that you ride in more adverse conditions than the average mortal and everything got bound up. All the intricate pivots/gears each built up a little friction and all of a sudden it won’t do the harder job of upshifts. Have you physically tried to rotate the mechanism and the lubed it and see the difference? It’s obviously binding .
Jim Langley says
Thanks for the comment, John. To explain more, I expected to find wear in the nylon worm gear because that’s what Shimano had said is what likely failed. I ruined the derailleur to take it apart and can’t now put it back together again to test whether I could fix it by super lubing it.
rod baird says
Thanks for the great tear down video on the front derailer. I was always curious how those little mechanisms operate it. On a similar note with DI2, I’ve had some problems with the batteries on my wife’s DI2 system; which is circa 2015. Recently the battery has begun dying after just about a week of use. There are some online videos that show how to (Hack) a battery replacement but they seem pretty sketchy (Soldering a connection directly onto the terminal of a lithium battery isn’t the worlds safest technique), but there’s clearly a need for a strategy to avoid spending $150 to replace The entire battery back when all that’s necessary is being able to replace two 3.7 V lithium batteries. They retail for about $35 a pair. Do you or any of your readers know of a well thought through way to replace the batteries themselves in a DI2 seat post battery pack?
Jim Langley says
Thanks for the report on your Di2 system and the battery issue, Rod. I do not know any way to repair the batteries. If I needed one I would buy the correct replacement from Shimano just to be sure the system would work and if I had any issues Shimano would provide support.
As the first comment stated, two words, Sram Etap!! I’ve got 4 bikes now with red etap 11 speed. Absolutely flawless, no shifting wires like Shimano. I ride till the rear battery shows red then put the front battery on the rear and charge the other one. I assume there’s probably a number of cycles to failure for the derailleur mechanism but I’ll bet it will outlast me! I’m sold.
D L says
Many, many different points of views. I guess I’ve been lucky so far. I have Ultegra Di2 on one of my road bikes for over 6 years and average about 6,000 mi. per year. I’ve not had any problems what so ever with them other than having to replace the battery once. On my other newer rod bike I have Ultagra Di2 for the last two years and not problems what so ever. One previous mtn. bike I had shimano Di2 shifters on it for over three years and no problems. On my current mtn. bike I have wireless Sram Eagle AXS on it for two years so and no problems. My wife has Ultagra Di2 on her road bike for 4 years with no problems and loves them. I also absolutely love electric shifting and can not see myself going back to mechanical shifters. Anything man made can have problems mechanical or electronic. I myself and plenty of others I know have had their share of problems with mechanical shifters. I say to each their own, if you like mechanical shifters then go with them. If you like the ease of electronic shifting, especially if you have arthritis in your hands as I do, then go with electronic shifters. Thank God everybody is not stuck in the past and don’t think things can get better as we go forwrd.
Steve Kurt says
Thanks for showing us what’s inside the magic box! I enjoyed seeing the potentiometer wipers on the round gear segment that meshes with the worm gear. The wipers contact a resistive element and a conductor on the facing circuit board, and this is how the microprocessor knows the position of the derailleur. At a glance, it appears to be in good shape, but some close photos would help confirm it. As an electrical engineer, I wouldn’t mind seeing some details of the circuit board too, but imagine that most of your readers/viewers just care about the part that failed.
Jim Langley says
Thanks for that tip, Steve. If I ever tear down Di2 again I’ll take some close-ups of the circuit board.
I don’t understand how people think that buying such an expensive shifting system that if it lasts 5 years and had to be replaced they’re ok with that?! I have a bike with 30 year old components that still work like a charm after over 150,000 miles, I personally would not be ok if an component only lasted 5 years, or even 10 years! And something that expensive should last at least 30 years. But I get what’s going on, it’s all about companies wanting you to spend money, this is why appliances use to last 30 years are now only lasting 8 to 12, and so it is with bike components that would last 50 years or more are now only good for 5 or so years, they want you to spend your money.
I agree. Components should last until they suffer catastrophic impact damage. In 50 years of riding bikes with derailleurs I’ve only had has to replace one RD. My Rival RD impacted spokes during a downshift and broke at the knuckle. On the mtb I went otb and I watched in horror as the RD crashed into the only rock on the trail. An easy trailside hanger replacement fixed me up. 5 years later that mtb rd still works fine.
Graham Nellist says
My linkage arm has broken/stroke failed on my Di2 Dura Ace I’m out of warranty but how do I get it repaired