SRAM continued in-house testing of its upcoming electronic group this past weekend with at least two employees – Mike Hemme and Scott McLaughlin – running the prototype bits at the Midwest regional championship event in Chicago, Illinois. SRAM kept the bikes under wraps until it was time to race but we still managed to get a few fresh images to share.
So far, it looks like everything we hypothesized in our earlier article is holding true: SRAM is sticking to a one-button format for the levers and there are separate wires joining each derailleur to a combination 'brain'/battery up front. Currently, there is definitely no clutch on the carbon fiber rear derailleur pulley cage, which at least for now is wholly shared with the standard Red 22 unit.
The front derailleur shares the current Red 22's hybrid aluminum-and-steel construction along with a different version of SRAM's trick 'Yaw' angle-adjusting geometry. While the mechanical version's sliding pivot mechanism is visible from the outside, the electronic version appears to have it tucked away in the inner pivots. As a result, SRAM's system shouldn't need to automatically trim depending on rear cog position as does Shimano and Campagnolo.
We now believe that the box mounted atop the stem is a combination rechargeable Li-ion battery and 'brain' as there still appears to be no additional connection to an internally mounted power source. The current electrical tape mounting system is obviously a stopgap measure but perhaps we while see tabs for an o-ring style attachment method. What's still in question, however, is where SRAM intends for this box to go. Road racers will likely be able to tuck this underneath the stem but as these images show, 'cross riders running cantilever brakes might not have sufficient room.
What's also interesting to note is how small the unit is. Shimano and Campagnolo have both had to battle with consumer fears that an electronic drivetrain would prematurely run out of power but now that both systems have proven to last far longer than they really need to, we can't help but wonder if SRAM has taken the aggressive position of downsizing the battery to save weight. The inclusion of the Yaw-style front derailleur should help in this department as that cage will only have to move during an actual front shift, thus reducing the power drain on the system.
What we didn't expect to see at all, however, is how production-ready everything looks. Several of the aluminum pieces still bear a pretty rough finish but others appear to have come out of more mass-manufacturing-friendly tooling. This seems to point to an electronic group that is getting close to production.