Orny's Cycling Journal

Whenever I talk to people about electronic shifting, someone inevitably freaks out. “OH MY GHAWD WHAT IF YOU FORGET TO CHARGE YOUR BICYCLE AND IT STOPS SHIFTING IN THE MIDDLE OF A RIDE?!?!”

Obviously, electronic shifting isn’t for everyone. Like any system, it has advantages and disadvantages. I wouldn’t condemn anyone for their preference for mechanical shifters, just as I don’t expect to be condemned for generally preferring rim brakes over disc brakes.

Di2 battery

However, let’s at least base our preferences on facts and reality, rather than “alternate facts” derived from wild conjecture and irrational fears.

In the case of electronic shifting, running out of battery power—whether thru actively depleting it without recharging or through letting the bike sit idle for months—will never be an issue for typical riders.

I started riding electronic in April 2013, more than four years ago, when I bought a bike featuring Shimano’s new Ultegra Di2 10-speed groupset. I’ve put 13,000 miles on that bike, or over 3,000 miles per year. And the data from my Di2 system tells me that on average I shift every 20 seconds while riding.

In all that time, I have never once depleted the battery. Was I a battery-charging maniac? Not at all. I usually charged it just three times per year: something like March, June, and September. And I virtually never had less than 50 percent charge, even if the bike sat idle for six months through the winter.

Until this year, I was getting 1,500 to 2,000 miles of riding on a charge. But in May I added another component to my system: the D-Fly wireless kit, which allows my electronic shifting system to communicate with my bike computer, to add gear shifting data to my ride logs and display what gear I’m in and how much battery I have left.

The D-Fly draws power from the battery to wirelessly transmit ANT+ data to the bike computer, so that noticeably reduced my overall battery life. But even with the D-Fly attached, I’m still getting two months and more than 1,000 miles of riding out of a single charge. Battery life simply hasn’t been an issue.

The people who cite battery life as a reason to avoid electronic shifting seem to think we’re still living in the 1980s, when NiCad batteries were state of the art. I have news for you: lithium batteries are lighter, smaller, have way higher energy density, don’t spontaneously discharge themselves over time, and don’t lose capacity by developing a “memory” after charging. Welcome to the 1990s; please update your expectations accordingly.

The only instance where battery life might be a limitation would be for ultra-endurance rides of greater than 1,200 miles where you couldn’t stop for an hour to recharge. I don’t know of anyone who rides 1,200 miles without sleep… Still, the obvious answer to that: carry a fully-charged spare.

For any normal rider, running out of juice is simply not going to be a concern.

Of course, I’m not saying electronic shifting is for everyone. I do appreciate the advantages of never breaking a shifter cable, never missing a shift, never worrying about crosschaining, and having gear and shifting data in my ride log. But I also acknowledge its drawbacks: it’s more expensive and can be really finicky to setup.

But running out of battery in the middle of a ride simply doesn’t happen, and anyone who says otherwise is either very misinformed, grossly incompetent, or intentionally lying to you.