Jim’s Tech Talk
By Jim Langley
Last week we were helping my friend and teammate Mike Andalora with tips on how to know when his shift cable needs replacing and how often he should do it. In response, “Russ,” “Stephen” and “Joe,” posted comments discussing Shimano shift cables that break inside STI shift levers. Joe mentioned that he’s never had problems with his circa 2002 Campagnolo shift cables.
To help them and anyone else with the problem here are two stories on the issue. Both are from last year and lots of readers have weighed in with comments so don’t miss those. Here’s Pondering Shimano STI Shift Cable Breakage And here’s Advice for Dave on His Breaking Campagnolo Cables.
Almost perfectly timed to coincide with last week’s story, Shimano announced that they’re finally delivering their promised 12-speed Shimano 105 R7100 mechanical groupset (drivetrain shown). This is your highest-quality option now if you want a cable-shifting Shimano group. Cost is said to be about $1,190.
It’s the only option because their latest higher end road offerings which were released earlier this year, 12-speed Ultegra R8100 and 12-speed Dura-Ace R9200 are both Di2 groups with electronic shifters. That means no shift cables.
If you’re building a gravel bike, they also recently announced a new cable-shifting group for these bikes, their 12-speed GRX RX820 mechanical components.
The good news is that Shimano is sharing components such as the crankset, cassettes, chain and brakes between their 105 Di2 groupset and their new 105 mechanical. Plus the 12-speed 105 cable-shifting derailleurs and levers are brand new. Which should mean high quality components that work together perfectly.
Since if you want cable shifting components this is your only option I think it’s important to compare the weight. According to Bike Radar the total weight of 105 R7100 is 2,845 grams (6.27 pounds). While Shimano Dura-Ace R9200 Di2 2,514 grams (5.54 pounds) – for a weight savings of .73 pounds. These weights are ballpark because it depends on the specs you run but clearly one of the penalties with R7100 is it’s heavier, which may or may not matter to you.
Cables Versus Wires: Shifting Performance
I believe that shift cable failures had some part in Shimano’s decision to eliminate cable shifting from their best road component groups. Electronic shifting doesn’t have any cables that stretch or break inside the levers. Shimano’s version now only has short lengths of wire exposed too and they’re pretty safely tucked in and unlikely to get broken.
In February I purchased a Trek Checkpoint SL-5. It’s equipped with a Shimano GRX 11-speed mechanical group with shift cables. Here’s my review: https://www.roadbikerider.com/new-trek-checkpoint-sl-5/ and here’s my video review:
The bike’s so much fun that I’ve logged thousands of miles on it so far. And even better, thanks to riding pals who have been exploring, I’ve tagged along with them on awesome (sometimes extremely challenging!) new routes in the Santa Cruz Mountains that I never knew were there – even though I’ve been riding here for 42 years.
But once a week I usually do a hill repeat training ride because intervals are so beneficial for maintaining strength, fitness and health. For that I switch from the Checkpoint to my Cervelo S5 aero road rocket. That bike has Shimano Dura-Ace Di2 shifting.
What Makes Electric “Better”
Going back and forth between mechanical and electronic shifting regularly, it’s easy to appreciate why you’ll hear that electric shifting is “better.” Because it is “better” in terms of the effort to shift and the shifts themselves.
Shifting Di2 is a little like clicking a touchpad on a computer. You tap the shift lever and the derailleurs shift. There’s no effort required to push the shift levers as there is with cable shifters. Plus with rear shifts there’s also hardly any delay in the shift, you’re in the next gear almost immediately. With front Di2 shifts it’s not as fast as rear shifts but it’s still faster than cable shifting. On my GRX drivetrain the lever travel to shift is long. And it requires effort – especially for front shifts.
The other thing about electric shifting is it doesn’t change until it’s worn out (and it does wear out – see my video about a worn out Di2 front derailleur: https://www.youtube.com/watch?v=eZO0av3EOW4 ). But, while it’s working the way it should, for at least 5-7 years (30,000 – 50,000 miles), it shifts exactly how it shifted when it was set up.
To explain, I put quotes around the word “better” because in my opinion while electric shifting does shift better, I don’t think that electric shifting is better overall than mechanical. Because mechanical is more durable and fixable. When a Di2 derailleur fails it must be replaced. Plus, with electric components there are batteries and chargers – technology that changes fast and can render things obsolete rapidly.
It would be fun to hear your experience with electric shifting if you’re riding it and/or your reasons for not giving up on your mechanical-shifter.
Jim Langley is RBR’s Technical Editor. A pro mechanic & cycling writer for more than 40 years, he’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Tune in to Jim’s popular YouTube channel for wheel building & bike repair how-to’s. Jim’s also known for his cycling streak that 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.