The junction box on Kristin Armstrong's SRAM wireless TT setup - Ben Delaney / Immediate Media
Kristin Armstrong won the opening time trial of the inaugural Women's USA Pro Challenge aboard this Felt with SRAM's still-not-released wireless TT group - Ben Delaney / Immediate Media
Single buttons are wires to the junction box, which transmits wirelessly to the derailleurs - Ben Delaney / Immediate Media
The buttons are pressed once to shift the rear derailleur in one direction, and pressed at the same time to shift the front derailleur - Ben Delaney / Immediate Media
The wires from the extensions and the cowhorns feed into the junction box - Ben Delaney / Immediate Media
What exactly does the junction box do? SRAM won't yet say - Ben Delaney / Immediate Media
With the Eurobike trade show coming up next week, we expect SRAM to finally start talking about its new group - Ben Delaney / Immediate Media
Kristin Armstrong's SRAM Quarq with unbranded rings. Rotor isn't a team sponsor - Ben Delaney / Immediate Media
We expect to see more logo'ing soon on these derailleurs - Ben Delaney / Immediate Media
K-Edge took its name from this rider, having built the original chain catcher for Armstrong's succesful bid at the Beijing Olympic time trial - Ben Delaney / Immediate Media
Speedplay's Aero pedal - Ben Delaney / Immediate Media
K-Edge accoutrements can be found across Armstrong's bike, such as this Garmin mount - Ben Delaney / Immediate Media
No, these are not Vittoria tires. Why do you ask? - Ben Delaney / Immediate Media
Armstrong's road bike for stages 2 and 3 - Ben Delaney / Immediate Media
This is the first year the race has had a women's component, which is three days - Ben Delaney / Immediate Media
What self-respecting racer would run this many spacers?! Well, one who has won numerous Olympic and world champion medals, thank you very much - Ben Delaney / Immediate Media
SRAM eTap wireless road group made numerous appearances at the USA Pro Challenge, including on Armstrong's road bike - Ben Delaney / Immediate Media
SRAM eTap rear derailleur - Ben Delaney / Immediate Media
50/34 Rotor Q Rings for Armstrong's road bike - Ben Delaney / Immediate Media
Not all teams use K-Edge mounts - Ben Delaney / Immediate Media
Microshift components aren't often seen - Ben Delaney / Immediate Media
Check out the chainstay - Ben Delaney / Immediate Media
A few of the women's teams had pre-race setups not too dissimilar from amateur squads - Ben Delaney / Immediate Media
Robin Farina flies the flag for Selle SMP - Ben Delaney / Immediate Media
Farina's race pedal for the time trial? Shimano 105 - Ben Delaney / Immediate Media
The low-stack design of Cipollini's Nuke TT bike - Ben Delaney / Immediate Media
The young Axeon team enjoys a full complement of SRAM/Zipp equipment - Ben Delaney / Immediate Media
The front end of the Cipollini Nuke, with removable caps for brake access - Ben Delaney / Immediate Media
Axeon had a few bikes with SRAM wireless and a few mechanical setups - Ben Delaney / Immediate Media
Drapac's Swift TT bikes have this unusual single-column riser - Ben Delaney / Immediate Media
SwiftCarbon will be coming to the US market in 2016 - Ben Delaney / Immediate Media
The gusty winds and steep climb in the middle of the course had riders considering all manner of options. This is Trek rider Matthew Busche's bike - Ben Delaney / Immediate Media
Funny bikes bring out the funny saddle arrangements. This is SmartStop rider Evan Huffman's bike - Ben Delaney / Immediate Media
Stack it up (at back) or slam it down. Diamondback's Serios TT bike gives riders some height-adjustment options - Ben Delaney / Immediate Media
Tri saddles snuck into TT. Now these ISM saddles are being increasingly found on regular road bikes, such as this Diamondback belonging to Tom Zirbel - Ben Delaney / Immediate Media
UHC's Kiel Reijnen has been the one non-BMC rider to win a stage (on day 3) at the USA Pro Challenge - Ben Delaney / Immediate Media
Guess why Wilier calls this bike the Twin Blade - Ben Delaney / Immediate Media
Good for Reijnen - he had a wind-friendly rig on a windy day - Ben Delaney / Immediate Media
Although Cannondale-Garmin could run internal Di2 batteries, the teams likes the accessibilty and the solid mount of the external option. And although the team could use Garmin's Vector power-meter pedals, the riders generally choose to use an SRM for power - Ben Delaney / Immediate Media
With multiple world and Olympic gold medals under her belt, the 42-year-old Kristin Armstrong can seemingly win time trials with the flip of a switch — or, as was the case on Friday at the USA Pro Challenge, the press of a button. Armstrong rode to victory in the opening stage of the inaugural Women's USA Pro Challenge aboard a Felt with SRAM's yet-unreleased electric time trial group.
SRAM still isn't talking about the group, but components are out in the open now. Armstrong's bike had bare buttons on both the extensions and the cowhorns, with wires running to a junction box atop the stem. The junction box then communicates wirelessly with the derailleurs.
With men's and women's teams setting off on the 8.5-mile course in Breckenridge, Colorado, there was a heathy mix of time-trial gear on display. WorldTour squads like BMC and Cannondale-Garmin mixed with composite squads from Colorado. Shimano Dura-Ace Di2 and Shimano 105 alike were raced.
While K-Edge chain catchers, Garmin mounts and number plates are somewhat ubiquitous now in the pro peloton, that wasn't always the case. It's only fitting that the original K won Friday on a bike with the equipment that was originally designed for her.
Check out the gallery above for a close look at the time trial gear at the USA Pro Challenge, and be sure to follow all the race action at Cyclingnews.
Single buttons are wires to the junction box, which transmits wirelessly to the derailleurs: single buttons are wires to the junction box, which transmits wirelessly to the derailleurs