Electronic shifting for bikepacking

Electronic shifting on bikes is both praised and dismissed. With its upfront cost and maintenance, it’s on the pricier side and, besides some advantages, it also brings drawbacks. The point of this article isn’t to glorify electronics or to bash it, but to offer enough information so you can make an informed decision about whether you want to use it. Even if the price tag is the same for everyone, it represents different value to each rider. You have to answer what value it brings you.

Since I’m a user of the SRAM Eagle AXS system (specifically the GX model), my description will mostly refer to it, but it will also serve as a description of electronic shifting in general.

Electronic shifting has two basic components:

Shifter

What stands out at first glance is the lack of housing and cables. It’s just a shifter (more of a rocker paddle) that you very simply mount on the bars. You can shift with your thumb or index finger.

Once you pair your unit with the app, you get access to advanced settings that wouldn’t be possible with mechanical. For example, you can choose which button shifts up and which down.

They are truly just buttons, so you don’t need to apply the extra force that would move a cable and the whole mechanism. It’s really just click, click. In the app you can activate multi‑shift, where a longer press will step through 2, 3 or all gears. Personally, I don’t use it and just click manually because it feels faster to me. But the speed at which you can downshift three gears at once can’t really be compared to mechanical.

The rocker itself is removable. SRAM offers a different ergonomic version, and there are third‑party makers who offer another alternative.

The shifter is powered by a coin‑cell battery. It lasts roughly 6,000 km, but it’s wise to carry a spare because it dies at the most unexpected times. It’s also good to have something on you to open the battery cover.

You can also buy so‑called Blips—separate buttons for the aero bars. What bothers me with this system is that SRAM doesn’t make the batteries in them replaceable. Once they’re dead, you buy new ones. That seems crazy to me.

Derailleur

Installation is again very simple. (In theory) just mount it and pair with the shifter. So no fishing cables through internal routing.

The connection is very stable, although it’s happened to me about twice (roughly once every 10,000 km) that it got stuck. In that case, just pop the battery out and back in and I was good to go.

If there’s a problem with the shifter (like the battery dying), there’s an emergency button on the derailleur. With one or two presses you can manually shift up or down.

The derailleur is powered by a lightweight SRAM battery with a proprietary charger. Runtime depends on how much you shift. I’d estimate around 20 hours. Below freezing, it can drop significantly.

Pairing with your phone and head unit

Most electronic gadgets pair with other electronic gadgets. The first thing worth pairing your derailleur with is your phone. As mentioned above, the app brings a few advantages:

• You configure the shifter behavior.
• You update firmware.
• Via “microadjust” you fine‑tune the shifting. You can do that directly via the shifter too, but in the app you clearly see the current setting. Functionally it’s an alternative to the inline barrel adjuster. I see lots of room for improvement here. If you could apply this per gear, you could very simply resolve issues from a bent hanger out in the field.

What I definitely recommend is pairing with your head unit:

• You’ll get low‑battery notifications
• The head unit beeps when you hit the highest or lowest gear. I missed that for a while, because with mechanical I get mechanical feedback at the extremes. The electronics is silent and has no speaker on its own. Garmin saved me here.

AliExpress alternatives

To save money, I tried a few alternatives for batteries and the charger from AliExpress.

Their charger is great in that it’s USB‑C, so I can finally have just one cable. It has two basic problems:

• There’s a little open hole where water can get in. The original probably isn’t waterproof either, but here it’s really opened in one spot.
• It can’t charge completely flat batteries. If I’ve used a battery past some critical threshold, I need to stick it in the original charger.

I also tried an AliExpress battery that promises more capacity than the original, but I didn’t have a good experience with it. It barely lasted. Maybe a bad unit, because other people’s experiences suggest they’re OK.

Advantages

More precise shifting with no force

If you’ve been out for a week and conditions aren’t great, mechanical shifting requires more and more force. Dragging a grime‑laden cable is a pain. A long ride is great for the mind, but not so great for the nerves in your fingers. That makes shifting harder.

With no stretched cable, precision goes up. By the end of races I’d always complain that gears no longer landed neatly. Electronics isn’t a silver bullet. If your chain is dry and your cassette is full of crud, that won’t be great either. But you remove the part of the system that can degrade shifting.

One less cable on the bars

I don’t mean the looks. When I hang bags on the bike, cables often get in the way. If a bag presses on them, it hurts shifting accuracy. Not to mention that what isn’t there can’t break…

Battery

You didn’t expect that, did you? The battery has one interesting advantage. Without the battery, the derailleur won’t move. If I shift into the easiest gear, remove the battery and leave the bike outside a shop, any “new owner” won’t have an easy time (or rather will have too easy a time) and won’t get far.

Disadvantages

Charging

Sure, charging is a hassle. Both for daily rides and on long trips, where you have to swap a battery mid‑ride.

Pairing the derailleur with your head unit is very useful. It warns you in time that the battery is getting low. I’ve noticed that with an almost empty battery, shifting performance can degrade, so it’s good to swap it early. I also think running batteries completely flat isn’t particularly healthy.

Swapping is very easy. Pop the cover off, click the battery out, click a fresh one in. You’re done in ten seconds. Stopping for it is, of course, annoying.

I always carry two batteries. They’re fairly small and weigh almost nothing. For a really long trip I also bring the charger, which unfortunately is micro‑USB only.

While I’ve never had an acute issue with the derailleur itself, the battery tends to lose capacity in bad conditions:

• In cold weather, batteries generally last less. I don’t have exact numbers because for regular rides the capacity is sufficient.
• In heavy rain/mud the battery can lose some of its capacity. I’m not sure why, because the batteries are of course waterproof. But it’s not entirely rare; at Italy Divide it happened to at least two people. The battery still works, but the charging interval gets shorter.

The battery capacity is only 300 mAh, so it’s not a huge power‑bank hog. Your light, head unit, or phone will draw many times more. Tips on how to charge electronics while bikepacking.

Nobody fixes electronics

If something breaks, it breaks—and no one will do much about it. This drawback is hard to quantify and maybe partly just fear of new things. As mentioned above, electronics has no cable that could go bad. And on the flip side it has electronics that people don’t fully trust.

Sure, one day it will fail. Nothing lasts forever. But everything can be dealt with somehow. If a mechanical part of the derailleur broke, I’d have to go to a shop anyway. And if I’m already there and the electronic repair isn’t possible, I can always go back to mechanical.

I’ve been “lucky” enough to have an electronic derailleur die on a race. Searching online I found that the Achilles heel of AXS groups are the pins that connect to the battery. One pin got pushed in, which then destroyed all the batteries I had. I later learned that the damaged pin can be temporarily fixed with a bit of aluminum foil, say from a Fidorka wrapper. The newer Eagle Transmission AXS supposedly suffers from this much less.

Price

Not much to add here. Everything costs a fortune. The derailleur, spare batteries, basically anything from SRAM. And it’s not just the initial investment. My batteries gradually die and I have to buy new ones. I also feel like the motor in the derailleur itself weakens over time.

Using electronic shifting for bikepacking

Most of the techniques are already in the text above; this is more of a closing summary. What I always try to do on my trips is minimize hassle. This is one more thing to think about. That said, on one charge the battery lasts me a whole day (in Switzerland even longer, because I push uphill and it rolls by itself downhill :)).

If I were going to less developed countries for a longer trip, I’d probably take a mechanical derailleur. In worse weather it does sometimes happen that the electronics give up. After all, for Tour Divide and the Silk Road Mountain Race I chose a mechanical groupset.

If I had enough budget and rode around Czechia or Europe, I’d have electronics on the bike. It’s simpler to maintain.