Electronic Shifting FAQ

Service Captain, Chris Warren, admiring new SRAM eTAP

Frequently Asked Questions about Electronic Shifting

By now you've probably heard of Shimano's Di2 and SRAM's new eTAP Wireless groupsets. Below is a collection of questions we've been asked. Feel free to let us know if you have more!

1. Woah! Is that even reliable?
2. Why would I want electronic shifting? 
3. Does it need regular service? 
4. Can I service it myself? 
5. How long does the battery last?
6. How long does it take to recharge the battery?
7. How many recharge cycles can the battery take?
8. Are the components light?

  

Woah! Is that even reliable?

     Yes! Shimano Di2 has been available since 2009. It has been thoroughly vetted on the professional and recreational level. SRAM Red eTAP components were tested in secret for years before they were spotted in the pro peloton and have received widespread praise since their recent public release.

Cervelo P5 with 9070 Di2

Why would I want electronic shifting?

     Because you can!
     But seriously, in both Shimano and SRAM the shift quality is superior to the shift quality of the mechanical groups. The elimination of traditional shift cables means no more derailleur adjustments for cable stretch. It means no more frayed cables. It means no need for barrel adjusters. It means no rusty shift cables. In fact, the electronic components are safe in sweaty conditions and rainy days too. The components are also very aerodynamic, in part, because of the wiring (or lack there of).
     Probably one of the biggest reasons to lust after electronic shifting is the ability to add accessory shifters. Everyone knows that mechanical shifting can only have one shifter per derailleur, but with electronic shifting the signal can be sent from multiple points. Triathletes can now shift from the aero bars, or the basebar. Roadies can shift from the hood position or a “sprint” position. If you fall somewhere in between a tri-geek and a roadie – you can have road style shift levers and shifters on a pair of clip-on aero bars!

Does it need regular service?

     Electronic shifting doesn’t require the same type of service, but it will still need occasional check overs. There are still physical derailleur limits that need to be set and derailleur hangers to be straightened, but most people will find that their semi-annual tune ups will be sufficient. Periodically, the manufacturers release firmware updates to fix bugs and improve things like battery life.

Shimano Di2 Charger/Update Interface

Can I service it myself?

     Sure! The set-up is relatively simple for those that have some mechanical inclination. While the actual processes are outside the scope of this post, stop by and see one of our expert mechanics for assistance.

SRAM eTAP Firmware Update Dongle

How long does the battery last?

      The Shimano di2 battery will last on average 3-4 months depending on the number of shifts. Some riders have reported as long as 12 months on one charge and upwards of 4000 miles. The A Junction box also functions as a battery indicator and will give an indication in 25% increments plus a critical level.

      The SRAM eTap derailleur batteries (each derailleur has it’s own battery) last for approximately 600 miles or 2-3 weeks. This is also dependent on how often you shift. Since the shifters are wireless, they also have their own batteries. These batteries are CR2032s, so they aren’t rechargeable but are expected to last two years.

But I’m still worried, what happens when the batteries die?

      On the Shimano system the as the battery drops to around the 10% level the front derailleur functions stops first. Your last shift will allow you to drop to the small ring. This leaves you the rear derailleur function. This will operate until the battery runs out of juice, and you’ll be stuck in your final gear combination.  We recommend charging the battery when you see the flashing red on the battery level indicator (around 10%).

      On the SRAM system, you’re rear derailleur battery will fail first, because you use it more often. Lights on the derailleurs will let you know as you reach approximately 25% remaining. SRAM is rumored to be working on a battery indicator screen/data field for your Garmin. When the rear derailleur battery runs out of juice, you can swap the front and the rear derailleur batteries and be back in action. In fact, you could potentially swap back and forth several times to efficiently climb hills on the way home. The batteries are also small and light enough to carry an extra in a saddle bag.

SRAM eTAP Battery and Rear Derailleur

How long does it take to recharge the battery?

      The Shimano Di2 battery takes 1.5 hours to recharge. The seatpost battery requires a charger that plugs into the A Junction. The external battery requires a separate charger that the battery plugs into.

      The Sram eTap batteries recharge in 45 minutes each. They require a standalone charger (included in the upgrade kit).

How many recharge cycles can the battery take?

 
     The Shimano battery can be recharged 300 times at 100% integrity. This practically means you’ll never have to replace the battery, because after 300 recharge cycles you’ll be ready for a new bike!
     SRAM batteries are rated at 100 recharge cycles. So, the batteries won’t last as long as the Shimano batteries, but they will last a long time. When you need a new battery, a replacement is available for $40.

Are the components light?

      Of course!! While Sram Red mechanical is the lightest full groupset out there, SRAM eTap is the 2nd lightest configuration available, followed by Shimano 9070 Dura Ace Di2. Ultegra 6870 is the heaviest electronic configuration and also is slightly heavier than it’s mechanical counterpart, Ultegra 6800.

Argonaut with SRAM eTap and Lightweight Wheels, only 14lbs!

GPS Running Watches

In the very recent past, running with a GPS watch was like wearing an iron shackle on your wrist; they were large, heavy, and expensive. The technology has come a long way. Smaller, lighter, cheaper, and much more fashionable, most of the current generation watches aren't any bigger than a basic stop watch and have many added features. A quick size comparison of three popular Garmin models stocked at ATC shows little resemblance to ye olde Medieval torture devices:

Garmin 910xt, Fenix 2, and Forerunner 10

Forerunner 10

The simplest, most affordable, and smallest offering is the Forerunner 10 at $129.99. Available in a variety of colors and two different sizes, the watch is minimal enough to work for everyday wear, so you don't have to take it on and off for runs.

The Forerunner 10's key features include the ability to track distance, pace, and time and to estimate calorie use. It can also notify you of personal records, such as fastest mile or longest run to date, and provides a "virtual pacer" so you can set target pacing goals. Data can be uploaded to Garmin Connect or imported into the analysis tool of your choice via USB.



Forerunner 220 and 620

A little bit more conspicuous in size, the Forerunner 220 and 620 watches bring added benefits with the bulk: the extra screen space provides more room for tracking your run stats, and the size seems to allow for quicker satellite acquisition than smaller watches. These two models also have longer battery life and more storage than the 10.

The 220 provides mobile phone integration to automatically upload your data, as well as training features like heart rate alerts, real-time live tracking, and a built-in accelerometer that lets you know distance and pace data even when running on an indoor track or treadmill. The 620 takes things a step further with a touch screen and the ability to estimate VO2 max, predict race times for certain distances, and suggest recovery time; it's also the first GPS running watch that provides feedback on running form (via accelerometers that measure torso movement). The 220 starts at $249.99 and the 620 at $399.99.

Forerunner 910xt

This is the big daddy watch that does it all. If you don't mind the size, the Forerunner 910xt is the triathlete's dream watch. Water resistant to 50 meters, it can track your swim, run, and your bike, including collecting data from your power meter. No need to manage different devices for all three sports, you can just use your 910xt everywhere; transition is possible with the press of a single button.

Swim metrics include swim distance, stroke identification, stroke count, and pool lengths, and GPS captures your path, which after the fact makes it easy to see how far you veered off course in an open water swim... Leave the 910xt on for your whole race and forgo a separate head unit on your bike if you prefer. If you like to watch your numbers closely on the bike, a quick release mount allows the watch to move easily from wrist to handlebars. Battery life is 20 hours, so even on a bad day it will last for your entire Ironman. The 910xt retails for $399.95 (Without the hrm bundle)



Fenix 2

If you spend any time hiking or trail running, or branch out into other adventure sports like paddling, climbing, and skiing, this will be the watch you want. Possessing all the same features as the Forerunner 620, but with a more rugged design, the Fenix also has an on-board altimeter, barometer, and compass, which are used to add a remarkably advanced set of  navigation and tracking features. Built-in sensors provide data on heading, elevation, and even weather changes, and you can leave a "bread crumb trail," marking waypoints like campsites, start/finish lines, and other points of interest. Battery life is 50 hours in GPS mode and up to five weeks in watch mode.

The future is now...the Fenix 2 integrates via Bluetooth or ANT+ with other compatible Garmin devices or smartphones, and in addition to easy data upload, you can receive text and email alerts and even use the watch as a glove-friendly remote for certain action cameras.

With a price tag of $399.99, the Fenix makes you wonder why people would spend thousands of dollars on designer wristwatches that simply look pretty and make a satisfying ticking noise when they could have a timepiece that ensures survival from snowstorm, zombie apocalypse, and bear attack.

Alright, alright... We're not sure it'll do anything for bear attack, but we wouldn't doubt it. And while snowstorm and zombie apocalypse have roughly equal odds of occurring in Austin, we say it never hurts to be prepared.