SRAM’s new Red eTap wireless drivetrain hits Shimano Di2 and Campagnolo EPS where they’re weakest, and matches their strengths. It’s more modern, more savvy, and more user-friendly. SRAM will offer the eTAP setup for triathlon and TT bikes right away. With more triathlon bikes at every price point featuring integrated setups, the wireless system has the potential to be a game changer for triathletes.
– It’s electronic.
– Wireless with a custom protocol (no Ant+ or Bluetooth) called Airea.
– New shift logic — only two buttons, left shifts to easier gear, right to harder gear, press both for front shift.
– Quick setup, complete build in less than 15 minutes.
– Extra shift buttons, called Blips, available (including TT setup).
– 45 minutes to charge batteries, 1000-kilometer run time.
– Weight within spitting distance of Red mechanical.
– Only cable-actuated brake levers are currently available.
ETap is an electronic system, just like Shimano’s Di2 or Campagnolo EPS. But it takes electronics a step further, removing the wiring harnesses that both those groups rely on, and switching to an entirely wireless communication between the shifters and derailleurs. Each component in SRAM’s new system is self-contained, with its own battery and wireless transmitter. They just need to be bolted to the frame, synced together, adjusted, and you’re off.
Shift logic is changed completely. Shimano and Campagnolo both chose to keep their shifter function virtually identical to that of their mechanical groups — SRAM emphatically did not. I think SRAM’s new shift logic is more logical.
There is only one shift paddle per shifter. The left shifter paddle shifts the rear derailleur inboard, to an easier gear, while the right shifter shifts the derailleur outboard, to a harder gear. If both buttons are pressed at the same time, the front derailleur shifts.
Left, easier. Right, harder. Both, front shift. It’s that simple.
The rear derailleur acts as the ‘brain’ of the system. In wireless terms, it’s the master and the front derailleur and shifters are slaves. It’s about 20 percent bigger than a standard Red rear derailleur, and weighs 239 grams, almost 100 grams heavier than a standard Red rear derailleur. That’s also 26 grams heavier than a Dura-Ace Di2 rear derailleur, which doesn’t have its own battery.
The Red eTap derailleur features a carbon cage and ceramic pulleys, just like the mechanical version, and installs just like a normal rear derailleur.
A small, rechargeable lithium ion battery is attached to the back and weighs 24 grams (this weight is included in the 239-gram figure). This battery will last about 1,000 kilometers, according to SRAM. It is identical to the battery used on the front derailleur, and will drain quicker as it is used more frequently. That means that should it run out, a rider can swap the front derailleur battery to the rear and continue onward with a functional rear derailleur.
Both front and rear derailleurs have small LED lights that indicate battery life with every shift. A flash of green is good. A flash of red indicates that the battery is down to 25 percent, about 250 kilometers. Repeated red flashes indicate imminent singlespeeding.
The front derailleur uses the same Yaw tech as SRAM’s mechanical derailleurs, so it doesn’t self-trim like a Di2 derailleur. It does overshift and then settle back into position, to make shifts faster.
An aluminum outer cage is matched with a steel inner cage for durability and a composite tail to drop some weight.
The front derailleur weighs 180 grams; about 75 grams more than a Di2 front derailleur (which, again, relies on a separate battery) and will cost you $370. The rear derailleur costs $590.
The single, large paddle on the shifters is nearly identical to current SRAM mechanical shifters, though it doesn’t move as far before a shift is initiated. SRAM says it went through over 40 different versions of button placement, keen to find the most intuitive, but its original design turned out to be the best. Given that all three major brands have a shift paddle in this exact spot, this fact isn’t surprising.
Small CR2032 batteries, the same as those found in many power meters, heart rate straps, and other small devices, power the shifters. These are not rechargeable, but will last at least two years, according to SRAM. The shifters are simply sending a signal, and function in a similar manner to the key beeper you use with your car (which lasts a very long time). The battery lives behind a small cover on the top of the hood.
The hoods themselves have gone on a diet. They’re slimmer than their mechanical siblings. The rubber material is the same, and shape is generally the same, with a similar knob and nearly identical reach to the brake levers.
Those brake levers, which are carbon fiber, are much stiffer than before, and it’s noticeable when braking.
At 260 grams per set, the shifters are 30 grams heavier than Dura-Ace Di2. They’ll set you back $580.
Shimano has its “sprint shifters,” SRAM has Blips. They’re small button pods that attach, via wires, to ports in the shifters. The wires come in four different lengths, and two of them can be plugged into each shifter. That means you could run a total of six shifters on your handlebars, if you want to look ridiculous.
The Blips weigh only 6 grams, and cost $200 for a set of four.
For those using aero bars without a standard road shifter, the Blips can plug into a Blipbox instead. The Blipbox has all the same wireless tech as the road shifters, allowing the Blips to talk to both derailleurs. The Blipbox weighs 31 grams and costs $300.
Setup is easy. Very easy. With no cables to fiddle with, or internal routing to curse, setting up a brand-new bike takes less than 15 minutes. One of SRAM’s mechanics set up a time-trial bike’s shifting, a process than would normally take at least three nights and nine beers, in less than six minutes.
If you’re not running Blips, road setup is even easier. Simply mount up each part, and start the simple syncing process by holding the “function” button on the rear derailleur, which is right next to the indicator LED. Hold that down until it glows green, then move onto the front derailleur and do the same. Repeat with the shifters. Green lights means everything is paired up and ready.
Limit adjustments on both derailleurs are nearly identical to a mechanical setup. You simply need to back the rear derailleur limits out a bit so the motor isn’t working against the physical limit, as that could damage the motor.
Once limits are set, micro adjustments can be made using the function button on the back of the shift paddles. Pressing the function button on the right shifter, then pressing the right shifter paddle (this is easy, just pinch the paddle and push in), the rear derailleur will microadjust to the right in 2/10mm increments. Do the same with the left shifter and it will microadjust to the left. Hold both function buttons and the front derailleur can be adjusted in the same way.
There is no ‘adjust mode,’ as with Shimano. Whenever a function button is held down, that’s adjust mode. Let it go and the system will shift normally.
Read more: Velonews.com