Both the rear derailleur and shift levers are far more polished than the last version we saw.

It appears wireless road bike shifting is getting very close to becoming reality in the consumer marketplace. Both the Bissell Development and Optum Pro Cycling teams are racing what looks (and feels) like a highly refined version of SRAM’s yet-to-be-released electronic shifting drivetrain at the ongoing USA Pro Challenge stage race in Colorado this week.

On Thursday, RoadBikeReview got an exclusive up-close look at the updated system that was first spotted at the Tour of California. The pictured bike is the Trek Madone of Frenchman Clement Chevrier (Bissell Development) who’s currently leading the seven-day race’s best young rider competition.

The biggest immediate difference between SRAM’s prototype and Shimano Di2 — aside from the lack of wires — is the actuation feel. Where Shimano uses a button or buttons that makes almost no noise, the SRAM system has a more-mechanical looking and feeling shift paddle that produces an audible click when actuated. This will be an attractive feature to those who complain that previous electronic shifting systems lacked feedback, and could be tricky to operate in cold-weather conditions, especially if the rider is wearing thick gloves.

SRAM has moved away from its double-tap shifting actuation found on its mechanical groups. Instead, the left paddle moves the rear derailleur one way, the right lever has the opposite effect, and depressing both levers simultaneously moves the front derailleur up or down.

A source with the Bissell team says mechanics received the new groups just after the Tour of Utah, which concluded on August 10th, and that it took longer to pull off the old cables than install the new wireless system. “The biggest issue with setting up the shifting was making sure the derailleur hanger was straight,” said our source, alluding to the sheer simplicity. “If that’s right the rest is simple.”

All the team’s Trek race bikes, both primary and back-up, are now spec’d with SRAM wireless. Same goes for Optum, which as SRAM PR man Michael Zellman noted, was a good sign. “You can read into the fact that more teams are using it,” said Zellman, who would not answer deeper questions about the group or speculate on a release date.

The front derailleur is operated by clicking both shift paddles at once.

Some members of the Bissell team received their rebuilt bikes just a day before the USA Pro Challenge kicked off, but according to a team source, the learning curve was short and there have been no major issues, just a few small tweaks.

With that level of refinement, it seems a safe bet that the group will be coming to market next spring. As it stands now, its been about six years since rival Shimano released its wildly popular Di2 electronic shifting drivetrain. But SRAM’s new group was finally leaked in earnest at the Tour of California back in the spring. Now it’s further out in the open and performing in tough conditions.

According to our Bissell source, none of the team’s riders had any issue during Monday’s stage 2 ride from Aspen to Mt. Crested Butte, which was punctuated by driving rain while the bunch was pedaling up and over Kebler Pass, which has extended dirt road sections.

Two days later, the evidence of that ride could still be seen when the battery was removed from Chevrier’s bike. But despite the slight grit build-up inside the battery mount, shifting is claimed to have been flawless throughout the race’s first three stages.

No wires on the bike of Frenchman Clement Chevrier, who is leading the USA Pro Challenge’s best young rider competition.

Even at the Tour of California the look, shaping and finish of the levers and front and rear derailleur were fairly refined, but SRAM has since responded to some of the team’s feedback, further polishing the rear derailleur and adding a lower limit screw, while also adding some texture to the hood surface, which was completely smooth in California.

Batteries and motors are integrated into the front and rear derailleur, and are easily removed for charging. Bissell riders have been riding on the same charge all week, which is being done at the request of SRAM as means of testing battery life.

System communication is likely achieved via ANT+ or Bluetooth, which means the system should be able to interface with various head units allowing riders to track things such as current gear and cadence.

Besides cleaning up the look of bikes, the wireless system will eliminate the headache of running wires or cables through a frame. One mechanic we spoke to estimated that it takes him about two hours to build up a fully prepped frame with a mechanical or wired electronic system, but that time would be cut in half with a wireless set-up.

Wireless shifting will also be a boon to time trail bikes, which often have circuitous frame shapes that make running cables or wires an exercise in mass frustration. “If they can bring a wireless system for TT bikes to market, the clouds will open up and angels will sing,” said one mechanic working at the USA Pro Challenge.

SRAM has refined the shaping and look of the prototype shift lever and adding some texture to the hoods.