The groupset was paired with a Quarq DZero power meter crank when the bike was built up and has been in use for a couple of months now.


SRAM Red eTap

Riders counting grams will be happy to know that the new technology only adds 80 grams over the class-leading mechanical Red groupset, with the claimed weight of the BB30 model coming in at 1,992g and 2,096g for the GXP groupset. That compares favourably to Shimano's Dura-Ace Di2 9070 at 2,047g. Fitting an upgrade kit (front & rear derailleurs and shifters) to a Shimano 105 equipped bike, knocked close to 300g off the total bike weight.

The brake levers can be adjusted for reach using a 2.5mm hex key. And that is where customisation ends as SRAM felt there was no need to add further complexity to the groupset. Based on my experience, I must agree. Changing gears is unlike any other groupset but it's quick to learn. Shifting the front derailleur is done by pressing both shifters at the same time. If you're in the big ring it will drop to the small ring and vice versa. Easy. Shifting the rear derailleur into the biggest cog is done by pressing the left shifter and to shift into harder or smaller gears you have to press the right shifter. In simpler terms: left shifter to move the chain to the left and right shifter to move the chain to the right of the cassette. This is by far the simplest shifting logic on the market and should make many a rider happy. The system also allows you to trim the derailleur on the fly should the need arise.



Shifting multiple gears is performed by either individual pushes of the shift lever or by holding the shifter down until you hit the desired gear. This is made easier by the Garmin or Wahoo head unit integration. By pairing your device to the groupset you can have your gears, gear ratio, battery life and gear combination displayed in real time. Pairing a device is quick and those familiar with adding sensors to their devices won't have any problems with eTap.


I am running a Quarq DZero crankset on our Specialized Venge long-term test bike but for those looking for a standard crank, there are several chainring options. SRAM Red chainsets are available in 46-36T, 50-34T, 52-36T and 53-39T versions and in six crank arm lengths from 165mm up to 177.5mm. Unlike Shimano, FSA, and Campagnolo, SRAM still has standard 130 and compact 110 crank options and it would be great to see them adopt a single standard that works with all chainring sizes as it would make future upgrades simpler.

Another choice you will have to make upfront is rear derailleur length, as Red eTap comes in short cage (maximum 28T) and medium cage (up to 32T) versions. If you're not sure of frame compatibility, you can have a look at SRAM's comprehensive fit guide before finalising your order.

Battery Life

There are two types of batteries in the eTap system: Two rechargeable ones (one per derailleur) that are interchangeable and two CR2032 coin-cell ones (one per shifter). Battery life is dependant on use but the derailleur batteries are good for around 1,000km of riding per charge and take about an hour to fully recharge. Based on usage patterns the rear should discharge quicker than the front, but you will be able to swap the front out with the rear in order to get yourself home should it ever happen. Fortunately, there are LED indicators to keep you up to date on battery life. Green means a full charge of 50-60 hours, red means 5-15 hours left and a blinking light means less than 5 hours left and that you should probably recharge after your next ride.

The coin-cell batteries in the shifters are good for 1 to 2 years of riding, dependant on use, and also come with LED indicators to warn you in advance of low batteries.

On The Bike

Overall shifting is precise, quick, and performs well under load. SRAM's engineers studied shift speeds at length and the final speed they decided upon was based on user experience, chain management, and battery considerations. At first, rear derailleur shifting seems slower than usual, but the short lever throw taints that a bit I reckon. I prefer shifting to be positive and precise over ultimate speed, so I was happy with the performance of the groupset.


The one lever, one task system was a highlight for me as there can be no accidental shifts or going the wrong direction on the cassette. Shifting remains solid and precise regardless of your winter or early morning attire thanks to the simple system and good paddle design employed by SRAM.

It may not seem important to some but I also like the fact that the shifting layout allows you to change gear while braking without the worry of hitting the wrong button or pushing the wrong lever. This becomes especially handy when you have to focus on hitting the apex of a corner at the bottom of a hill with a climb on the other side. No need to shift too far ahead or worry that you will lose momentum around the corner by being in the wrong gear. I did this by pulling the brake lever with my index and middle finger while using my ring finger to push the shift paddle.

The hood, lever, and paddle shapes are all good with no complaints from my side. Some may prefer slightly different shapes but, other than personal preference, the are no oddities that stand out or will distract from the overall feel. As mentioned above, there is room for reach adjustment to fine tune the brake lever.



For the purpose of this review, I ran the front derailleur battery completely dead and was pleased to feel no difference in its speed or performance until the moment it finally gave up and died. I don't think the user experience would have been as positive if shifting deteriorated with battery life.

The performance of the rim brakes matches that of the groupset by being exactly what one would expect from the top of the range brakes in SRAM's road line-up. The overall feel is good, pairing good modulation with ultimate stopping power.



Being late to the electronic groupset party afforded SRAM the opportunity to assess rider and pro feedback and pick their fights carefully. For a first version, the system is very mature with good attention to detail and clever solutions.

SRAM's wireless groupset is mechanical made better with several advances in use and performance. There are no funny quirks or signs of them trying to do something different just for the sake of it. Using RED eTAP is the quality user experience one would expect of a top-tier groupset.

Quarq DZero power meter crank

The DZERO was announced in late 2016 as a replacement for the Elsa and Riken power meters. It features a new measurement circuit, a revised strain gauge design, improved accuracy throughout the pedal stroke, and a new app called Qalvin App which provides free firmware updates and is used to set the zero offset, check battery voltage, and run diagnostics.


Power output is measured from both legs with 1.5% accuracy and data can be captured using Dual Bluetooth low energy technology or ANT+ depending on your needs and other devices. The DZero comes with an IPX7 waterproof rating, 2-year warranty and has been programmed with over 10,000 data points to eliminate temperature effects on power measurement.

Power is supplied to the power meter by a CR2032 coin-cell battery (like the ones used in the eTAP shifter) and is good for 200 hours. Quarq say 300 hours should be doable, but rather claims a conservative figure for extreme use or weather conditions like staying and cycling near a pole. Conveniently the battery is housed in front under the "Q" and can be accessed and replaced without any tools. There is a LED indicator that matches the eTAP battery level warnings.

DZero is offered with aluminum or carbon crank arms, 110 or 130mm BCD and hidden bolt (one of the spider arms is covered by the drive-side crank arm) or non-hidden bolt spider. Shimano riders can opt for the DFour (which comes with carbon crank arms only) and there are options for mountain bikers as well.

No cadence magnet is required as the built in AxCad (Accelerometer based) provides that measurement and Quarq's OmniCal means you can swap chainrings without affecting accuracy.


  • Bluetooth low energy technology and ANT+ wireless data transfer.
  • No cadence magnet required.
  • 10K Temperature Compensation
  • CR2032 battery, 200-hour battery life, change without tools.
  • Power Balance
  • Swap chainrings without affecting accuracy
  • 2-year warranty
  • IPX7 waterproof rating
  • Accurate to within 1.5%, measuring both legs
  • Free firmware upgrades with the Qalvin app
  • 690g (compared to a standard RED crankset's 610g)

On The Bike

The first thing to get out of the way is how it fairs as a crankset and I am happy to report that there are no issues here. The cranks feel stiff and solid under power and have been holding up well after several months of use.


When it comes to measuring power, I have found the DZero to be accurate compared to other power measuring devices used. Looking back at the recorded data, there are no inexplicable spikes or drops between it, the Kickr and PowerTap 1 pedals used. Using Zwift indoors I have noticed a bit of a lag in reading updates on Zwift's side, but looking at the recorded data together they are all in-line with each other. Unfortunately, the P1's were a borrowed set that the owner (understandably) wanted back so I've had to make do with most comparisons being between my Kickr and the Quarq.

There has also been no discernible difference when paired to my Garmin 820 or a Wahoo ELEMNT we had on test.


After several months of use, the Quarq DZero has proven itself to be accurate, easy to use and as close to set and forget as a power meter gets. Other than the odd preventative calibration to keep it in tip-top shape, it has not needed any TLC from my side, fires up with the first pedal stroke and sends its data to my head unit of choice without fail.