Will wireless shifting be a game-changer? SRAM introduces eTAP
For the past three years we’ve seen spy shots, speculated amongst ourselves, spotted fake cables, and seen it openly on the bikes of development teams and on WorldTour teams at the Tour de France. We’ve all keenly watched SRAM’s progression into the world of electronic shifting and there hasn’t yet been a dramatic raising of the curtain.
But now we can say without conjecture that SRAM eTAP is finally here. It’s a significant milestone for SRAM that will either make or break their credibility in the road market; a market they’ve earned their place in. After riding the groupset for three solid days in Schweinfurt, Germany, I can say with confidence that they’ve done something truly revolutionary. For time trial and triathlon bikes, it could even be labelled a game-changer.
Wireless shifting provides a host of benefits, and few drawbacks. Of course, this isn’t to downplay the strengths of existing wired electronic shifting systems on the market; systems which have been proven to be extremely reliable and have perform exceptionally.
SRAM says that the number-one failure in electronic shifting systems are the connection points. In a wireless system, if you push the button and nothing happens, you can always push it again and it will work (assuming it’s not a battery problem).
Another benefit to wireless systems is the simplicity of installation and compatibility with frame types. This isn’t so much of an issue with road frames these days, but with cable routing on time trial bikes and the new aero road frames being so complicated, a system without shifting cables becomes an attractive proposition.
The biggest potential drawback in a wireless system is the fact that each active device (shifters and derailleurs) in the system needs power, and the only way to get power to each device is by connecting a battery directly to that device. However, read on and you’ll see some clever ways that SRAM has minimised this issue, and even capitalised on it.
It took four years of development, nearly one million kilometres of field testing, and the navigation of 450 electronic shifting patents to get to this point. Perhaps the most refreshing part is that SRAM was able to come up with a remarkably simple, intuitive and effective way to shift: right paddle to shift down, left paddle to shift up, and both at the same time to shift the front derailleur.
For time trial bikes, the shifting is achieved through SRAM’s “Blip” shifters, which are remote buttons that can be placed anywhere on the bars. Road bikes can also use up to two pairs of the Blips. You find out more information about this in the photos and captions below.
The first question many of you are probably asking is “what does it cost”? The manufacturer’s suggested retail prices are:
eTAP Road Groupet: $2,758 USD, € 2,691, £2,059 No word on Australian pricing yet.
eTAP Aero Groupset: $2,835 USD, € 2,785, £2,140 No word on Australian pricing yet.
eTAP will be available for purchase in spring of 2016.
The next question you weight weenies are going to ask is “what does it weigh?”
In total, the eTAP road groupset weighs approximately 2,030 grams (including brake cables and GPX bottom bracket), which is slightly more than the claimed weight of 1,739g for Red 22 mechanical.
Initially, battery life was my biggest question. There are four batteries that make up the system: two CR2032 batteries on the shifting hoods, and one lithium-ion battery on each of the front and rear derailleurs.
You’ll be happy to know that the CR2032 batteries will last for a two years (claimed) before they need to be replaced. There’s very little power consumption on the shifters because all they’re doing is sending a short-range signal to the derailleurs every time you shift.
The derailleur batteries aren’t quite as robust, but they’re rated for 1,000 kilometres in the worst-case scenario. In all likelihood, they’ll last much longer. The charge process takes 45 minutes and the batteries can be removed and charged on any USB port.
There are battery life indicator LEDs on each of the components, but if you happen to run out of battery on one of the derailleurs, they’re easy to interchange so you can at least get back home. Some might even consider carrying a spare battery in your saddlebag like you would a tube.
There has been a lot of thought put into power management in order to help extend battery life. Each of the derailleurs has an accelerometer built in which puts the units to sleep after 30 seconds to ensure no battery power is lost.
If one of the levers is pressed for more than 15 seconds, it also quits transmitting to prevent battery drain. This has been a problem with other systems — you might accidentally lean the shifter up against something and unknowingly drain the battery. If you ever hear of a battery going flat without warning in an electronic shifting groupset, this is probably what happened.
Battery chemistry = Lithium Ion Polymer
Rated Capacity = 300mAh
Rated Voltage = 7.4v
How it rides
I got to experience eTAP for three decent rides and first impressions were solid. The shifting process was simple, intuitive to understand and use. The ergonomics haven’t changed from the previous Red groupset which was good. The mechanical “click” was a welcome feeling and even riders with thick gloves and/or on bumpy roads will not go through a millisecond of doubt that they’ve hit the shift.
Personally, the only small issue I had with three days of riding is that I intuitively thought that the right shifter should go up the cassette instead of down, but that will fade with time. SRAM says that they debated this internally for some time, but in the end it was a fairly arbitrary choice. At this time, there’s no software that lets you configure and customise your shifting options.
How the wireless communication works: ‘AIREA’
For those of you who want some technical details, read on. Otherwise, feel free to skip this section.
AIREA is a personal area network (PAN) protocol developed by SRAM specifically for the eTAP application. SRAM wasn’t able to give more details on the AIREA protocol stack, but I assume it’s a paired back and simplified variant of ANT+ or Bluetooth LP.
No other technical information was provided in AIREA — what can be said is that it is modulated on a 2.4Ghz (frequency hopping spread spectrum), 128-bit encrypted channel which enables the communication path from the shift paddles to the front/rear derailleurs (which also communicate amongst themselves).
The rear derailleur also transmits ANT+ to talk to Garmin devices which show the gear the derailleurs are currently in.
SRAM say that electromagnetic interference has been well tested in a multitude of environments and they’re confident that AIREA is rock solid against accidental interference, jamming, and hacking. SRAM has reportedly only been able to count a handful of times a mis-shift has occurred in all of their testing.
Sure hacking is theoretically possible, but the transmit/receive radius is approximately 100 meters and each device can only be paired with one other device (if something comes unpaired, the whole system needs to be re-paired). Combined with 128-bit AES encryption, FHSS, and hopefully the lack of will by hackers, SRAM is not concerned about a lack of security in the slightest.
To upgrade the firmware on eTAP, a USB stick (Mac or PC) is used to communicate with the system to receive updates. At this time there is no way to customise/configure the shifting or run diagnostics from external software. At this point, SRAM says that they see no need.
We had a demonstration of how simple it is to install eTAP. Of course there are no differences with installing the brakes, but some massive gains are made with time and simplicity with the derailleurs and shifters. The tools required are similar to that of a mechanical groupset.
- The front derailleur (FD) has a wedge to prevent front flex on the frame when shifting
- Pair the groupset starting with the rear derailleur (RD) (this takes about 20 seconds in total to do)
- Adjust limit screws on RD
- Chain sizing – same as past systems
- RD micro adjust (13 micro adjust clicks between gears (0.2mm each) using shifters in micro adjust mode. This can also be done while riding if the rider needs to fine-tune the shifting
- Set FD limits – exactly like mechanical
The only problem I anticipate for mechanics is the front derailleur adjustment. You’ll no longer have a spare hand to turn the chainset and shift at the same time. You’ll need both hands for shifting, which may cause grief, but I’m sure you’ll find a technique. Correction: The function button on both front and rear derailleurs will shift up or down without the need to reach for the shift paddles.
In all, eTAP is an elegant solution to wireless shifting that’s clearly been well planned, thought-out, and tested by SRAM. After three rides to get a feel for it, the only shortcomings I see are the following:
- The battery life is good but owners will need to be diligent with knowing where their charge is at. There’s no shutdown mechanism to give you a nudge to tell you to charge your battery. LED indicators only show you the battery life when the shift paddles are pressed, which you’re not likely to see.
- The “blip” remote shifters serve a TT set-up very well, however on a road set-up they’re difficult to find, place, and press while under the bar tape. They don’t serve the purpose as sprint shifters (placed on the inside of the drops) very well.
Other than that, every expectation has been exceeded, even if those were based on conjecture up until now.
It’s been said that electronic shifting is an electronic solution for a mechanical problem, but SRAM eTAP simplifies the overall system by removing the shifting and power cables. SRAM didn’t come into the electronic shifting market as a “me too” but as an innovator who solves some problems and takes electronic shifting to new level.
I was skeptical of many aspects going into this launch, but SRAM has made up for lost ground in the electronic shifting market and first impressions are extremely positive.