The Worthiness of Electronic Bike Shifting: Essential Things to Consider

Now that Shimano, SRAM, Campagnolo, and FSA all produce electronic drivetrains and have extensively tested, refined, and developed the technology over the past decade, almost every high-end bicycle comes equipped with a charging cable.

If you find yourself still riding a bicycle with mechanical shifters, you might be contemplating an upgrade to electronic bike shifters. This naturally leads to the question: Is it worth making the switch? (Sorry for the pun.) If you’re intrigued by electronic bike shifting, here’s what you should know beforehand.

Yes, you can upgrade your bike.

According to Shimano’s Road Brand Manager Nick Legan, transitioning from mechanical to electronic bike shifters can be as simple as swapping out four components: the Di2 shifters and derailleurs (along with adding the wiring harness and battery). However, this applies only to current 11-speed and 12-speed drivetrains. While electronic bike shifting is firmware-controlled, no company has yet released a firmware version that allows for adjusting the number of drivetrain speeds. Therefore, if your bike is equipped with older 10-speed components, you’ll also need to upgrade the crankset, cassette, and chain. (Although it’s possible to temporarily use 10-speed chainrings, it’s not recommended due to the tight tolerances between a 10-speed ring and an 11-speed chain.)

More From Bicycling The triangle icon that indicates to playFor SRAM, similar rules apply. Although neither company officially states that mixing parts is permissible, we’ll say it here: Unless you’re extremely particular, using a Shimano chain on a SRAM cassette, or vice versa, works perfectly fine with 11-speed drivetrains. It may just result in some additional noise. However, it’s crucial to note that none of SRAM’s AXS groups are compatible with non-AXS components, as they have modified the chain pitch and roller size slightly.

Electronic drivetrains may not be compatible with older frames.

If your bicycle features external cable routing, you’ll need to secure the wiring to the frame using zip ties. While technically feasible, this method may not offer the most aesthetically pleasing results. Additionally, Shimano’s new Di2 drivetrains utilize internally housed cigar-style batteries, which may not fit all frames. Most frames produced since 2012 include internal routing with cable stops that can be replaced with mechanical or electronic cables. In some cases, it may be necessary to purchase new stops through a dealer.

 

On the other hand, SRAM’s wireless eTap offers a convenient solution for upgrading older frames.

If you’re dealing with an older bike and don’t want the hassle of dealing with a wiring harness, SRAM’s wireless eTap is a great option. The batteries are conveniently mounted to the derailleurs, making the installation process much simpler. According to Brad Menna, SRAM road product manager, all you have to do is install the derailleurs and shifters, pair them, and you’re ready to hit the road.

Consider buying a new bike instead.

If your bike is of a certain age, it may be more beneficial to look into purchasing a brand new bike. Chad Nordwall, owner of Bay Area shop Above Category, suggests this approach for bikes that were manufactured before 2010. Retrofitting electronic shifting onto certain frames can be challenging, and if you’re already planning to spend close to $2,000 on a new groupset, Nordwall believes that getting a new bike would be more cost-effective. Additionally, purchasing a new bike allows you to take advantage of innovations such as oversized steerer tubes, lighter and stiffer carbon fiber frames, and the option for disc brakes if your current bike has rim brakes. While Di2-equipped bikes may start around $4,500, switching to a new bike might be the smarter choice if you’re set on transitioning to electronic shifting.

Rest assured, the battery won’t die on you.

When it comes to battery life, Shimano doesn’t make any specific claims due to the various terrains and conditions that riders encounter. However, even professional riders don’t typically charge the batteries on their training bikes more than five to six times per season. For most riders, charging the batteries on a quarterly basis should be sufficient. It’s more likely for a battery to die because it lasts so long that you simply forget to charge it. To prevent this, it’s recommended to set up a regular calendar reminder, such as Friday evenings at the end of each month. As for outlasting the unit’s charge cycle life, Chad Nordwall from Above Category reassures that in his experience, he has never seen a rider return with a completely dead battery for Shimano Di2 and Campagnolo EPS groups.

Discover the exceptional battery life of SRAM’s wireless eTap.

In contrast, SRAM claims that their batteries for the eTap system can last at least 15 hours on a full charge and potentially up to 60 hours. Even when the battery indicator turns red to indicate low power, Brad Menna assures riders that they still have at least five hours of ride time before the battery dies completely. The best part is that the front and rear derailleur batteries are interchangeable. If one battery dies during a ride, you can simply swap the live battery to the front derailleur, position it in the correct chainring, and then reposition it to the rear for shifting purposes until you reach home. For longer rides, it’s also possible to carry a fully charged spare battery in your pocket. When traveling, it’s important to remove the battery while flying with your bike as airlines may inquire about it. Once you reach your destination, make sure to recharge the battery, as some individuals have reported batteries draining during flights.

However, you will need a charger.

Ensure that your purchase, whether it’s a ebike or a groupset, includes a charger. Shimano’s current internal battery system utilizes an E-Tube charger box, which can connect to any USB adaptor. However, keep in mind that your bike must be positioned near an outlet for charging. Campagnolo’s batteries work similarly, featuring an internal design and requiring a comparable charging method.

On the other hand, SRAM’s eTap system uses an external charger. Each derailleur has separate, smaller batteries, and SRAM states that a full charge takes less than 60 minutes per unit. However, only one battery can be charged at a time, so it’s essential to allocate enough time to charge both batteries. If you wish to charge both batteries simultaneously, you can add an additional charging cradle to the system. Additionally, the shifters in the eTap system require CR2032 batteries, which may need to be replaced every one to two years depending on your riding frequency. To avoid running low on battery, consider setting up a charging station in your garage that includes your bike lights, cycling computer, and your bike. This way, you’ll always have enough power.

It will not go out of adjustment

The initial installation and setup of Di2 are best handled by bicycle shops, according to Legan, a former professional team mechanic for CSC and RadioShack. However, once it is done, an electronic drivetrain should consistently shift in the same way every time. Legan explains, “There is no cable stretch, and the motor shifts the chain at a consistent speed and distance with each shift.” Indeed, this reliable performance is one of the main advantages of electronic shifting.

If your shifting is not functioning properly, the likely culprits are a dead battery or a loose wire. It is important to check all connections. Shimano offers a PC-only software tool, an Android app, and an iPhone app that allow for customization such as reversing the shift button function or adjusting the shift speed. However, unless you enjoy tinkering with your bike constantly, it is probably easier to take it to a bike shop. SRAM claims that a competent home mechanic can set up eTap. Since there is no wiring harness except for the shifters to the stem-mounted CPU, Menna points out that once the derailleurs are installed and paired, the setup mostly involves adjusting limit screws and the B-tension screw on the rear derailleur. Additional adjustments can be made using the SRAM AXS app, which allows you to check your charge, personalize component behavior and controls, and update your firmware as needed.

Kei Tsuji//Getty Images

Take care with your tools

It is important to handle any sharp tools with caution, as they have the potential to damage electrical wiring. Even mundane tasks like re-wrapping the handlebar tape require care. Legan advises, “If the E-Tube wiring is under tension along the handlebar, when the tape compresses it, it can pull on the harness just enough to disconnect the E-Tube connector.” To prevent this, leave a bit of slack under the bars and double-check the harness connections to ensure they are secure. Additionally, never pull on the wires themselves. With SRAM, you do not have to worry about spare wires, but if you are using additional remote “Blips” shifters, be cautious when cutting the handlebar tape to avoid nicking the wires that connect the Blips to the shift levers.

When washing your bike, extra care is necessary. It is generally best to avoid pressure washing, but if you do choose to spray down a muddy bike at a car wash, be particularly cautious to avoid spraying the bottom bracket, handlebars, and derailleurs.Do not neglect maintenance

Nordwall emphasizes that because electronic shifting is so reliable, people often neglect to properly maintain their bikes. He explains, “Before, people would bring their bike in for maintenance when their shifting started to deteriorate. With electronic shifting being so good, by the time people bring in their bike, it’s already in bad shape—the cassette is worn out, the chainrings are damaged, and the jockey wheels are dirty.” The problem is that these components are expensive—something as simple as a Dura-Ace 9000 outer ring can cost up to $240. Regular cleaning and replacing chains before they become too stretched can prolong the lifespan of your drivetrain. Just because your shifting is working fine does not mean your bike does not need a little tender loving care.