Felt unveiled their new DA TT bike at the Tour of California this week, both on display in their expo booth and underneath some of the Garmin-Transitions riders. The bike just looks fast, but Felt says it has made some major improvements over the previous version, and has the numbers to back it up. Check out full photos and some of Felt’s claims about the new bike after the break…
By The Numbers
Felt says that it expanded both its computer and wind tunnel testing for the 2011 DA. The result is a faster, stiffer, and more efficient time trial and triathalon bike, two years in the making, utilizing brand new, cutting edge computer technology never before available to engineers. The production started with months of computer testing and prototyping, with each and every resultÂ double checked in the San Diego wind tunnel to ensure that it actually acted in the real world as the computer models predicted.
But how much faster, stiffer, and efficient is the new 2011 Felt DA? For starters, the company says the bike is 14 percent faster than its predecessor, and 13 percent stiffer. While the new frame has 25 percent more surface area, it is only two percent heavier for 2011, but an exact weight was not available. The bike is chock full of new features designed to improve aerodynamics, like the S-Bend downtube and lipped seat tube, which Felt says makes the DA the fastest TT bike on the market.
The Importance of Yaw
Felt also talked a lot about the efficiency and aerodynamics of the bike past zero degrees of yaw; the angle at which wind hits the bike. So, if a rider was turning or facing any sort of cross wind, the new DA is said to be more efficient in these real world conditions. When most bikes are tested in a wind tunnel, they are simply tested under head-wind conditions, without wind coming from any other angle other than straight on.
To counter this, Felt designed this bike to be faster between 10 and 15 degrees off angle, which creates a faster bike when the rider actually gets on the road, as opposed to sitting upright in the wind tunnel. The company says this is where a lot of the 14 percent speed increase comes from, making the bike much faster in real world conditions.
Photos and Features
The new DA comes fully spec’d with Shimano’s new electronic Dura-Ace kit, and many of the bike’s features were actually designed around the Di2 groupset. Garmin-Transitions riders used the electronic group in the Tour of California, and the new retail DA will come fully equipped with Di2 in 2011.
The new seatpost is designed around the Di2 battery pack, and Felt reps told us that the bike is actually aerodynamically faster when the battery pack is attached.
The seatpost clamp is redesigned for 2011, with a new, more durable clamp. There were lots of complaints floating around the internet about this part breaking on the 2010 DA, and Felt has corrected the problem for 2011.
Felt borrows some elements from the previous version of the DA, but made lots of improvements, mostly focused on aerodynamics. While the new Bayonet 3Â headtube and fork combo is almost functionally identical to last year’s version, it is 7mm narrower, down to 35mm, thanks in part to Felt’s decision to use 3/4″ bearings instead of the 1″ bearings used in the older model. While the Garmin-Transitions bikes and this prototype have fixed stems, Felt says the production model will have an adjustable rise stem integrated into the Bayonet system.
The gigantic bottom bracket shell adds strength and stiffness where it counts, and again, improves aerodynamics. The frame is spec’d with a BB30 bottom bracket shell, which means that Felt had to use adapters to fit the Dura-Ace bottom bracket.
In the photo above, you can also see the DA’s rear brake, mounted behind the bottom bracket to improve rear-end aerodynamics. Our pictures of the brakes didn’t turn out so well, but it uses a v-brake instead of traditional calipers. Felt says the v-style brakes are both more powerful and, of course, more aerodynamic.
Another view of the BB30 bottom bracket with a Dura-Ace 7900 crank.
The rear wheel hugs the seat tube ever so closely, but Felt insists that the production model will fall within UCI regulations. This prototype did not pass the credit card test (a credit card couldn’t slide between the wheel and the frame,) but the Felt rep said that the bikes the Garmin-Transitions team is riding and the production bikes will have a bit more clearance. The frame also has full carbon horizontal drop-outs, so the wheel could be slid back a millimeter or so to make more clearance.
Also notice the small lip along the edge where the seat tube runs along the rear wheel. Felt says this was put in place to “push” air out before it hit the rear wheel, improving aerodynamics by forcing air away from the rotating wheel, which reduces drag.
You can see just how close the wheel is here, and the gap tapers down as it moves down the seat tube. The proprietary seat stays are also all new for 2011. Felt says they quickly pull away from the rear wheel to, again, maximize airflow, something they had discovered with new computer and aero testing for 2011.
Pricing, Sizing, and Availability
While the Garmin-Transitions team is already equipped with the bikes, they won’t be available to the public until December at the earliest, but probably not until 2011. Because it was designed with specific components in mind, the bike will come fully equipped with Di2 electronic components, so Felt says this year’s model will be a bit pricier than the 2010 DA. The bike will come in a 48 cm frame designed for 650c wheels, and 51, 54, 56, 58, and 61cm frames will be available with 700c wheels.