Zipp’s VukaShift R2C time trial bar extension will go on sale later this month. Introduced at last year’s trade shows, its impending release gives reason for a closer look at the two direct-mount extension options from Zipp and three R2C aero shifter options available from SRAM and Zipp in 2010.
The standard VukaShift bar extension, which has been available for two years, is compatible with conventional time trial shifters from SRAM and Shimano. Both the standard and new R2C (Return To Centre) models of the VukaShift bar extension use the chicane shape and omit the need for plug-in expansion bolts. This is said to save roughly 80g per pair.
The extensions also allow seamless internal cable routing and bring the shift lever closer to the bar’s curve for better ergonomics, according to Zipp. The chicane shape can only be cut from the rear, which limits its total adjustment to 10cm. Shortening the grip with the direct mount moves the shifter 3cm closer, while still keeping your hand on the top of the bend.
VukaShift direct mount (top) and standard chicane extensions
When SRAM launched their version of the R2C Aero shifter, they went with a sharp, blade-like shape. Conversely, Zipp now offer the bulbous, bullet-shaped R2C shifter to consumers as the VukaR2C.
Both models use unidirectional carbon fibre for their levers, offer a 40-degree adjustment range for their starting position and come with titanium hardware.
Zipp’s version is claimed to be six seconds faster than a conventional shifter when measured at the benchmark 40km distance, because the R2C lever always returns to its optimally aero forward-facing ‘home’ position.
“There’s a really slight difference [between the Zipp and SRAM R2C shifters], like a couple of seconds, over 40k, with the advantage to Zipp,” said Andy Paskins, Zipp’s marketing manager. “But frankly, when you have your hands on them, there’s no difference.”
Zipp’s version is also available with a modified cable pull ratio that’s compatible with Shimano derailleurs.
During the 2009 Tour de France we saw both of these R2C aero shifters in use. At the time, the designs were all SRAM-branded. Saxo’s Fabian Cancellara tested the dagger-like version, while Astana’s Lance Armstrong went with the larger, curvier version.
SRAM say Armstrong has since changed to the blade-style shifter and that all of their ProTour teams are using their shifter shape.
All of the R2C shifters are available now. SRAM’s R2C Aero costs £294 (US$349) while Zipp’s two R2C models (SRAM or Shimano) cost £325 ($375). Both of the direct mount bar extensions cost £175 ($200). For comparison, the standard bar extensions in any shape cost £100 ($130). These prices do not include the cost of the base bar.