Cervélo was perhaps the first bike manufacturer to peg one of its bikes as having a dual personality: flip the seatpost in one direction for a more road bike-like geometry and general training, or rotate it the other way and install some clip-on aero bars when your local triathlon comes to town.
Upstart company Redshift Sports promises to add that same capability to nearly any road bike with its new Switch Aero system, which makes the conversion much faster and easier with no tools required.
Unlike reversible seatposts that need to be partially disassembled to make requisite setback changes, the Switch Aero post instead uses a clever parallelogram-like linkage.
In the rearward position the post provides a rather conventional -16mm offset. However, the saddle can easily be flipped about 50mm forward, to mimic a more triathlon bike-like, 76- to 78-degree seat tube angle – even while riding, according to Redshift's Scott Poff. He said the saddle also raises slightly when moved forward, to maintain a constant bottom bracket-to-saddle distance.
Redshift will initially offer the aluminum Switch Aero post in 27.2mm and 31.6mm diameters only, and for now there's no mechanism to firmly lock the post in either position.
Redshift Sports Switch Aero quick-release clip-on aero bars
"The current prototypes have a spring detent mechanism so it clicks firmly into both positions, but it’s not a 'lock'," Poff told BikeRadar. "The forward and rear angles of the mechanism were chosen so that the saddle will stay securely in place, even without any weight on it.
"The detent force provides extra resistance to prevent it from moving due to an inadvertent bump, but it’s light enough that you can still move the saddle on the fly by applying a bit of upward and forward/backward force, depending on which position you’re in. In testing we've found no tendency for it to move when you’re sitting on it unless you specifically try to move it."
Redshift has also developed a set of clever quick-release clip-on aero bars to go with the seatpost. A pair of semi-permanent aluminum brackets is bolted to the bars but the extensions and arm rests themselves then attach via a sliding dovetail interface, a small spring-loaded bar, and a cam-type lever to lock everything in place.
Arm rest and extension heights are independently adjustable, arm rest width can also be tweaked, and the standard-diameter extensions will be offered in straight, S-bend, and L-bend shapes. Users should only have to make those adjustments once since the system maintains your position with each removal and installation.
Poff said there's no provision to mount the extensions below the bar at present, but the base clamps will supposedly fit 25.4mm, 26mm, and 31.8mm-diameter bars. There are optional computer and water bottle mounts, too.
"In our experience, most age groupers don't have the flexibility to ride with much lower stack heights for extended periods of time," Poff said. "However, we are considering ways of lowering the minimum stack height in future designs."
The parallelogram linkage at the top of the Switch Aero seatpost is rather compact
As convenient as it sounds, the Switch Aero system won't do anything to temper a typical road bike's quick handling – which can be daunting for aero newcomers with so much weight shifted over the front wheel. Poff doesn't sound too worried, though.
"When riding a road bike in an aero position, the handling will be a little quicker than a triathlon bike due to the increased forward weight bias," he told BikeRadar. "That said, we’ve spent quite a bit of time riding with the prototypes and we’ve found that everyone’s been able to adjust quickly to the handling in the new position, and it's very stable once you get above 10-12 mph. Another nice feature of the system is that you always have the normal road position available when you need extra stability."
Redshift Sports is currently seeking financial backers for the Switch Aero system via Kickstarter. At present, the Switch Aero seatpost is pegged at US$109, the matching aerobars start at US$125, and a complete set begins at US$225. Corresponding computer and water bottle mounts are US$20-25.