Although plenty of attention has been focused on aero bikes and wheels in our quest to go faster, there's also been a steady advance in clothing technology, with the recognition that a rider comprises over 80 percent of the speed-sapping drag.
Today’s professionals all sport skintight outfits, aimed at easing their passage through the air – and it goes further than simply form fitting. Extensive wind tunnel research has shown the benefits of specific fabrics and seam placement, and Pearl Izumi have been able to utilise speed merchants Taylor Phinney and Marcel Kittel during development of their PRO Ltd Speed kit.
In wind tunnel tests, Pearl Izumi compared their new dimpled Transfer Aero fabric to a flat-faced stretch fabric, and found a 2.5W power saving at 50kph (31mph), which equates to 0.7 secs/km or an eight percent energy saving at 25mph. The improvement was partly attributed to the placement of the stitching and different fabrics within the jersey and shorts. The combination is said to be more aerodynamic than many skinsuits, while retaining the practicality of a two-piece outfit.
The textured Transfer Aero fabric has a chequerboard pattern, and is used on the shoulders, sleeves and side panels of the jersey, with a slippery, smooth-faced front panel and thinner aerated back panel for cooling. The cut is excellent, with a super-stretchy fit that's still flattering and doesn’t inhibit free movement, and arm grippers that don’t squeeze.
Silicone dots on the rear prevent it from riding up, and rather than the usual three external pockets, the Speed Jersey has two very generous ones, and an internal waterproof pocket for your radio – or phone. Flatlock seams save any internal irritation, and the jersey has an SPF of 40+.
The shorts feature carefully placed flatlocked seams and 80mm-wide grippers made of folded Transfer Aero fabric, which combine to hold the shorts in place very comfortably. The lower legs and side panels use a shiny, smooth-faced fabric, with the remainder of the shorts in Transfer In-R-Cool for better cooling. The seamless 4D insert proved ideal on endurance rides.