Rumbles and rumors of a SRAM electronic system have been in the air since the first electronic drivetrain was unveiled way back in 2009, and it grew to a roar of anticipation prior to the eTap launch at the 2015 Eurobike and Interbike trade shows. The final production group lives up to our lofty expectations to redefine how we think about shifting and bike setup. Say goodbye to air-grabbing cable housing and finicky wire threading feeding power or shift information into derailleurs; instead, the Red eTap Aero Shift Kit delivers impeccable shifting precision and lets you outfit your TT whip with intuitive, customizable shift point locations.
SRAM's proprietary Airea communication protocol is the brain of the system, securely pairing the shifters and derailleurs with 128-bit encryption that resists both hacking and jamming for worry-free shifting — even in a pack of other eTap steeds. Designed specifically to drive eTap, Airea creates a unique encryption code for each individual drivetrain to ensure a secure, uninterrupted connection. Although this system is closed and doesn't allow shift reprogramming, SRAM is confident that the eTap shift logic delivers an optimal shift experience across road-related disciplines.
If Airea represents the system's firing synapses, the bodies they control are the derailleurs. Featuring the Exact Actuation technology found in mechanical Red derailleurs, the eTap rear derailleur manages the narrow spacing of an 11-speed cassette for reliable shifting accuracy and allows for multi-gear shifts with extended depression of the shift point. The front derailleur boasts SRAM's Yaw technology, which angles the cage ever so slightly as the chain runs across the cassette to maintain a consistent chain line, reduce chain rub, and increase efficiency for quiet, precise gearing across the entire range.
In place of traditional shifters, the Aero Kit includes SRAM's new eTap Blip shifters and a BlipBox control module designed to pair with aero bars. The Blips are a slight anomaly in the otherwise wireless eTap system because they feature wires that connect to the BlipBox, which then wirelessly communicates with the derailleurs. The wired design removes the need for individual Blip batteries, allowing SRAM to minimize their size so the Blips sit cleanly and stealthily wherever they're placed. Their small size also makes them exceptionally versatile, with placement limited only by the wire length.
The Blips have the same eTap shift logic as the more traditional eTap shift levers, only more customizable due to their virtually endless placement options. One Blip moves the chain down the cassette for a harder gear, the other guides it up the cassette for an easier gear, and engaging both simultaneously shifts the front derailleur between chainrings. The BlipBox features four ports, offering myriad potential to customize shifting by outfitting your TT rig with up to two pairs of Blip shifters.
The front and rear derailleurs each carry a rechargeable battery pod, which clicks into place quickly and easily and is interchangeable between the two derailleurs. While you shouldn't have to worry about running out of battery with their claimed 60-hour ride times, it's nice to know that if you forget to charge up and run out of rear derailleur juice out on the road, a quick battery swap from front to rear will get you back up and running with full access to the cassette range. For those of us wary of constant battery recharging, SRAM claims a fully charged rear derailleur battery will last over 1000km (620 miles), with the front derailleur theoretically lasting even longer due to its relative dearth of use compared to the rear.
As with the eTap road shifters, the BlipBox is powered by a CR2032 coin type battery with a predicted lifetime of two years. To keep tabs on the various battery levels, the BlipBox and each derailleur feature an LED indicator light to communicate battery life with green, red, and flashing red stages to clearly relay remaining power. Each component also incorporates an accelerometer that puts it into sleep mode when stationary to conserve battery and rouses it for full functionality when your bike is in motion.
SRAM claims eTap has been extensively tested in a wide range of riding conditions, both in the real world and the lab to ensure reliability. Given the cold-weather tolerance issues of its first generation hydraulic road brakes, we're particularly glad to note that SRAM confirms eTap has undergone testing in its in-house climate chamber, proving the system's reliability in temperatures ranging from -20 to 120 degrees Fahrenheit.
The SRAM Red eTap Aero Shift Kit comes complete with four eTap Blips with 650mm wires, an eTap BlipBox, an eTap front derailleur, and an eTap short cage rear derailleur compatible with a maximum cassette cog of 28t. The kit also includes an eTap Powerpack for derailleur battery charging and an eTap USB firmware Airea update stick. The kit is compatible with SRAM Red 22, Force 22, and Rival 22 cranksets and 11-speed cassettes up to 11-28t, though SRAM also designed a Red 22 crankset specifically to complement eTap's aesthetics. The special crank is functionally identical to the standard Red model, just styled to match the electronic drivetrain.
- SRAM's groundbreaking wireless system for TT bikes
- Airea wireless communication protocol is secure and reliable
- Blip shifters offer customizable shift point placement
- Interchangeable front and rear derailleur batteries
- Tested to withstand extreme weather conditions