A lot can happen in six years. For bicycle design, that’s nearly an eternity. Back in 2014, the bike industry was tepidly embracing 25mm tires as wide, and road disc brakes were about as rare as Bigfoot. That year also happens to be the last time Felt updated its AR aero bike. While fast, and loved by many, it certainly is feeling these days like a relic of another era, clearing only 25mm of rubber and offering only a rim brake option.
In the time since, Felt did some soul searching about what it should be as a company. For years, the California-based brand has offered a wide range of bikes, from carbon racing machines suited for professional cyclists, to alloy frames for budding weekend warriors, all the way to beach cruisers. It was really trying to cater to everyone. Today, Felt is reining in its focus, returning to what it has been best at: creating high-performance bicycles. The road bike offerings are being pared down to just a couple framesets, each available only in builds with high quality components like Ultegra.
Now, it’s 2020. Disc brakes are de rigueur, and riders want as much tire volume as they can get. Felt listened, and the new AR builds upon its predecessor in just about every way.
To eagle-eyed race fans, the new AR, though only officially announced now, will look a bit familiar. Familiar, because it has already won at the highest level: Rally Cycling’s Chloe Hosking took the opening stage of the 2020 Tour Down Under aboard the new AR—after wining two stages and the overall title at Australia’s Bay Crits Series. Mind you, the season is merely one-month old. So, what makes it better than the 2014 AR?
When Felt went back to the drawing board to redesign the AR, there was no question that it would be disc only. Beyond providing more stopping power in all riding conditions, disc brakes remove the headaches caused by aerodynamically optimized, but difficult to adjust, brake calipers on the previous AR. Felt says there was also a demand from AR owners to see a disc-brake option. Disc brakes are so integral to the new design that the brand is wholesale saying goodbye to rim brakes on the AR (though they are still available in the more traditional FR road frame).
Conventional wisdom once held that cyclists spend the majority of their time in higher yaw angle conditions. Accordingly, the previous AR was optimized for yaw angles of 15 to 7.5 degrees. But new research shows that cyclists spend a majority of their time in situations where the yaw angle varies from -10 degrees to +10 degrees. Studies differ, but the consensus is that anywhere from about 70 percent to 90 percent of time is spent riding at these low yaw angles. It is also worth noting that, shielded from the wind inside a pack in a group ride or race, cyclists will spend an even greater amount of time in these low yaw conditions. With this information in hand, Felt set out to create a bike that is faster in those low yaw conditions of -10 degrees to +10 degrees.
At the start of the process, Felt’s engineers spent about eight months to a year just testing tube shapes before anything else, estimates Alexander Soria, director of product development at Felt. Throughout the frame development process, they utilized a wind tunnel, ensuring they were getting the fastest bike possible. That constant testing helped them arrive at the new truncated tube shapes we see in the final product.
Wanting to be as transparent as possible, Felt has provided the following un-weighted data recorded by independent operators at the San Diego Low Speed Wind Tunnel comparing the previous AR to the new AR. “Faster” here means more aerodynamically efficient than the previous AR.
0 degrees = 9.4% Faster
-2.5 to 2.5 degrees = 7.0% Faster
-5.0 to 5.0 degrees = 5.2% Faster
-7.5 to 7.5 degrees = 3.2% Faster
-10 to 10 degrees = 0.7% Faster
If, miraculously, you spend all day at zero-degrees of yaw, this bike is going to provide a significantly faster ride than the previous AR. But that’s not quite what you should expect in the real world. As you experience higher yaw angles, the aerodynamic benefit begins to fall off, but remains present throughout the range of yaw angles most often encountered in the real world, as compared to the last AR, an already fast benchmark. Felt is willing to say that, in overall conditions, the new AR is 1.4 percent faster than the previous AR.
Wider Tire Clearance
New tube shapes are present throughout the AR. In the rear triangle, the chainstays and seattube take on a new “fish lips” design, which allows for wider tires of up to 30mm, up from 25mm, and also improves airflow.
Felt wanted to make the new AR not only faster, but more comfortable and better handling as well. One of the biggest upgrades in compliance comes from the new proprietary seatpost, which features a slot in its center, allowing both halves of the post to flex independently, resulting in a claimed 112 percent more deflection at the seatpost than before. To clean up airflow around the seatpsot, Felt includes a rubber piece that plugs the hole in the seatpost. Additionally, a damping sleeve made of plastic and rubber fits around the seatpost inside the frame to further soak up high-frequency road buzz. The option to run high-volume tubeless tires offers an additional way to introduce compliance.
And, of course, the bike got stiffer; did you even have to ask? Felt claims an 11 percent increase in lateral headtube stiffness; a 21 percent increase in lateral stiffness of the fork; and a 14 percent increase in BB pedaling stiffness.
Focusing-In on Road Riding
Some AR fans will be sad to hear that the reversible seatpost on the previous version, which allows for switching between a road and a TT position, is not making the leap to the 2020 version. Instead, Felt has opted for a post optimized for the fastest position possible for a road rider. But fear not, the saddle clamping mechanism is now reversible, offering the option of either zero degrees or 20mm of offset, a similar level of adjustability as the previous AR.
Some integrated cockpits of the recent past have sacrificed adjustability in the name of maximizing aerodynamics. Felt’s new semi-integrated system strikes a nice balance between aerodynamics and user-friendliness. Cables route under and through the stem, to a separate Devox Carbon Aero handlebar. The whole system maintains the adjustability of a traditional handlebar/stem combo. But if you have a stem you can’t live without, you have the option to easily swap in any traditional stem of your choice.
Conveniently, the stem can be removed without cutting cables, which makes disassembly and reassembly for travel easy. The stem faceplate also includes a slot, making it compatible with third party computer mounts like a Barfly.
Felt utilizes a form of carbon called TeXtreme, which uses flat tapes of carbon, rather than yarns of fiber, to pack more carbon into a given area for stronger layups needing less resin. This carbon replaces heavy unidirectional carbon in Felt’s layup.
But despite lighter carbon layups, the bike itself is a tad heavy. Our size 54 built up with Ultegra Di2 weighed in at 18.37 pounds (without pedals or bottle cages). Felt hasn’t made final production frame or fork weights available yet.
Proprietary Chain Catcher
The AR has one more trick up its sleeves: A proprietary chain catcher prevents the chain from falling off the inner chainring, and, should the chain manage to fall off, from falling into the bottom bracket. That’s a welcome addition.
Builds and Options
The AR comes in two build packages: mechanical Ultegra for $5,000 and Ultegra Di2 for $6,500. Both builds come with Reynolds AR58 DB Custom wheels and are available in two color options: white or blue. A frameset-only option costs $3,500 and comes in gray only.
Felt is taking orders starting today, with bikes expected to start arriving in late March.
We’ll be perfectly clear up front: The new AR is undeniably fast, and simply tears up the flats. Though the 58mm-deep Reynolds wheels are liable to catch a strong crosswind, the bike otherwise remains very rideable in light wind.
Downhill, the aero advantage only amplifies for blazingly fast descents. It’s a rocket that keeps finding the mph’s. Perhaps the most telling example of this bike’s speed is a small descent on a normal route of ours. It’s only a quarter-mile, but without even trying to go fast or set a personal record, we were the recipient of a new Strava gold medal on the segment. All said and done, we went five seconds faster in a quarter-mile descent—without even trying. Its handling on descents also impresses—not too twitchy, for holding a confident line, but still nimble enough to respond well to most winding descents.
It doesn’t take home the crown for most compliant road ride, but for an aero-optimized bike, the AR is pretty effective at soaking up the road chatter. The front end is less compliant than the rear, but this is partially a testament to the effectiveness of the new split seatpost and damping sleeve. We also find aero handlebars in general to be less comfortable than traditional bars—especially in the tops where they are missing bartape. Luckily, with the design of the semi-integrated stem, if you want to swap in traditional bars, the process is no different than with a traditional stem. We would also swap out the standard 25mm tires for 28mm ones for added comfort.
As a quick note, the Felt VelvetGel bartape feels excellent, and has a reflective layer subtly built-in that’s only noticeable when a light is shined on it.
Uphill, the AR’s weight catches up to you. (It’s especially noticeable if you’re coming off a lighter climbing bike). At 18.37lbs for a size 54, it’s no behemoth, but that extra mass weighs on your legs as the gradients increase and the speeds dip too low for the aero tube shapes to be worth much. Those who prefer to spend their days in the mountains will probably want to look elsewhere. But still, there’s no denying how fun it is to go back downhill on the AR after a long climb.
- $6,500 as tested
- 18.37lbs (size 54, without pedals or cages)
- Shimano Ultegra Di2 hydraulic (52/36 crank, 11-30t cassette); Reynolds AR58 DB Custom wheels; Continental Grand Prix 5000 25c tires; Felt integrated stem; Devox Carbon Aero handlebars; Prologo Dimension T4.0 saddle; Felt seatpost
- More info: feltbicycles.com