The place to learn about triathlon.

2011 Felt DA Di2

By Tom Demerly with Sarah Lieneke, Chet Ajsenberg, Jaclyn Applegate and Jack Johnson.

2011 Felt DA Di2
Felt's new 2011 DA is a complete re-design of a legacy bike. The new version emerges as a category leader.


Felt: A Heritage of High End Racing.
Felt is a racing company. It is their heritage, their origin. They started with two high end racing frames: one triathlon frame, one road racing frame. Each was handmade and race specific. With the introduction of their new 2011 Felt DA with Shimano Di2 they return to that origin at the top of category.

You may already know that Jim Felt got his start in motorcycle racing by hand building motorcycle frames for top factory racers. Felt’s projects included handmade racing bicycles that found their way, sometimes with different decal sets due to sponsorship requirements, under Scott Tinley, Greg Welch, Paula Newby-Fraser and many others in the sport’s formative years. The first of the Felt triathlon bikes was the venerable Felt B2 followed by the “DA”, an acronym for “Dual Aero”. The DA made use of an aero seat tube and down tube aerodynamic tubing unlike the original B2 which did utilized more round frame tubes.

2011 Felt DA Di2
A 2002 model year Felt DA. The "DA" name plate has been the masthead of Felt's aero bikes since the company began.

The new 2011 Felt DA is a complete redesign. This is Felt’s contribution to a shift we’re seeing throughout the industry. Designs from the previous 4-8 model years are getting old. Recent innovations in component integration and our understanding of low speed aerodynamics and rider positioning are improving. The previous Felt molds were shared by the DA and the “B” series triathlon bikes. The basic frame shape trickled down from the nearly $10,000 price point for the previous DA to models around $2000 for the value oriented “B” series bikes. The new 2011 Felt DA departs from that shape and carbon fiber lay up completely. It is totally new.

The New DA: The only thing they Didn’t Change is the Name.
The reason for a new design is tangible improvement. The newest version of the DA is a completely different, and better bike than previous DA’s. I’ll suggest it leads the newest “superbike” category. The ride quality is entirely different from previous versions. If you owned a previous model DA it will take about four pedal strokes and one hard side-torque at the cockpit to feel the difference on the new DA. It is that different. In shape, component integration and carbon lay-up this is a complete redesign.

“The 2011 Felt DA leads the newest ‘superbike’ category.”

The 2011 Felt DA we received is the complete bike, box stock. It uses a component list from the very highest end of the industry. Here’s a detailed look of the component spec and the frame:

The Bike and the Components: A Critique from Front to Back.
From the front of the bike we start with a Zipp 808 Firecrest tubular wheel. We’ve reviewed the Firecrest concept in video and print. This is an upgrade from previous Zipp wheel profiles and goes along with the updated technology of the Felt DA itself. There is no better wheel specification readily available.

2011 Felt DA Di2
The spec list on the DA is stellar: Zipp's new Firecrest front 808 tubular and the Devox cockpit.

The tire spec is the lightweight and luxurious riding Vittoria Triathlon EVO-CS tubular with Kevlar SiO2 3D compound. This is a high thread count, 320 TPI cotton casing tire with an integrated butyl (not latex) tube. The tire casing uses Vittoria’s Kevlar SiO2 belt to bolster flat resistance. At 322 grams measured weight the SiO2 belt adds a little weight in return for good flat resistance and does not change the perceivably excellent ride quality of the tire. Valve stems are 42 mm that come from Felt wrapped in white Teflon tape with Zipp alloy valve extenders installed. The tire valve cores are removable so the Presta valve could conceivably be moved to an extender with threads making inflation easier. Ride quality on these tires is truly superb with great shock absorption and gum-sole cornering. Because of the butyl inner tube, as opposed to latex, this tire will maintain tire pressure from 5:00 AM when you put your bike in the transition area to 9:30 AM when you get out of the water after an Ironman distance swim and throughout an entire 5-7 hour bike split.

The Cockpit: A Category Leader.
The cockpit on the Felt DA is the Devox 3:1 Bayonet carbon integrated base bar with integrated “f” bend extensions. Compare this cockpit to the Easton Attack integrated cockpit, the Zipp Vuka family, HED black dog and 3T Breeza. I encourage you to take the time to actually do the comparison too. You’ll find the Devox bar is perhaps the best bar in this category on bend, adjustability, ergonomics, stiffness and fit. The Shimano Dura-Ace Di2 controls integrate well with this bar both on the extensions and the base bar.

2011 Felt DA Di2
The Felt "f" bend extensions are highly tunable for fit. Elbow pads feature a substantial range of spatial adjustment.

“The Devox bar is perhaps the best bar in this category.”

The “f” bend extensions are a hybrid of a ski bend and an “S” bend striking a tangible balance between bends and fit-ability. In an aftermarket environment the Devox 3:1 Bayonet more than holds its own against the others. The bar is adjustable for extension and for bend by cutting. If you do cut the front of the extensions be certain the Di2 controller/shifter will fit all the way into the remaining extension. The elbow pads adjust for position, fore/aft and width although width adjustment is minimal. These are racing bars. You can make “rise” adjustment to the elbow pads by using the risers and bolts that come with Vision aerobars. Elbow pads on the cockpit are a clear gel pad that isn’t exceptionally plush. Some ultra distance triathletes will want a softer elbow pad.

So far Felt has nailed the specifications on the front wheel, cockpit and tires. I would not make a single change in any of these since there are really no upgrades from here.

The New Bayonet Front End.
The stem on the Felt DA is the Bayonet III integrated stem with a four bolt, carbon fiber front mounting plate to retain the handlebar system. The Bayonet III stems have adjustable angle for the attachment to the steering system, something missing from the Scott Plasma 3 and other superbikes. Three different length stems are included with the bike and, since the stems adjust up and down for angle, the fit-ability afforded by the stems in combination with the Devox Bayonet cockpit is extensive. A total of 9 different extensions is possible according to Felt using different stems. Additionally, a fixed position, non-adjustable fixed angle stem option will be available after-market.

Previous Bayonet stems were difficult to adjust and, after tightening, did not easily move when loosened to make fine adjustments. The fit and adjustment on the new version is better. It clamps securely and adjusts with reasonable effort. Another improvement.

2011 Felt DA Di2
The new Bayonet III integrated front end is mechanically evolved and aerodynamically very narrow. The melding of fork and head tube is impressive with fork blades designed to work well with any front wheel configuration.

“This new Bayonet is razor sharp, there are vast improvements. This is a Bayonet front end we can not only live with; we can win on and travel with.”

The Felt Bayonet III front end is a continued evolution of the previously troubled Bayonet concept. This new bayonet is razor sharp, there are vast improvements. This is a Bayonet front end we can not only live with; we can win on and travel with. It is mechanically simpler than previous designs since one critical adjustment bolt is no longer hidden and a host of improvements are in place. The primary technical feature of the Bayonet front end is how narrow the entire assembly is and how well integrated into the frame, fork blades and head tube area it is. Another benefit is excellent steering and front end stiffness out of the saddle.

Felt: Narrow is Aero- only 33 Millimeters Wide.
The entire frame in front of the bottom bracket is only 33 millimeters wide at its widest point. A Scott Plasma III is 47 millimeters wide at the head tube’s widest point. In other words, this frame is about as wide as a 32 millimeter touring tire. This bike is extremely narrow, harkening back to the legacy Hooker Elite design themes, the original ultra-low drag bike. The front of the bike is so narrow that proprietary, extremely durable headset bearings had to be configured for the new Bayonet.

2011 Felt DA Di2
Felt's proprietary front brake is designed for good aerodynamics with the Bayonet front end and has excellent stopping power. The front end also accepts a standard road caliper but this brake is so good there is no reason to consider a replacement.

The Fork/Wheel Gap: The New, Claimed “Most Aero”.
The architecture of the fork and fork crown on the Felt Bayonet III is designed to be “separate” from the front wheel’s aerodynamic behavior. In other words, Felt has found- along with an increasing industry consensus, that fork blades either need to be extremely close to a front wheel specifically designed to work with the fork, as with a front disk wheel, or the fork blades need to occupy a proximity far enough from the rotating wheel so that they are aerodynamically independent of the rotating wheel. Felt- along with others like Look, Litespeed and Quintana Roo and Trek – chose the latter doctrine since it affords customers a high degree of flexibility in wheel choice.

A Felt DA specific front brake was designed and made for Felt. It optimizes a number of design requirements unique to this bike. While the bike will take a standard front brake the Felt brake more closely mimics the shape of the fork crown behind it. This brake can easily adjust from older narrow rim wheels to the new wider trend in aerodynamic race wheels. Additionally, the brake has a stiffer feel and less mass since there is no need for to have the extensive vertical adjustment built into most off the shelf, non specific brakes. The feel of the brake is excellent- another of many victories on this bike. Brakes are actuated by the Shimano Di2 combination brake lever shifter on the base bars. Another Di2 shifter control is co-located on the aerobars. You can shift from both positions. Overall, this brake is very good.

The Wiring: Why Not Entirely Internal?
Much has been said about the inability of manufacturers to integrate the Shimano Dura-Ace Di2 wiring harness and battery pack into the frame. Scott suffered an embarrassing cancellation of a Di2 specific model of their Plasma 3 citing inability to source an optimal, allegedly “proprietary” wiring harness from Shimano for their bike. On many Di2 super bikes the wires and battery hang rather obtrusively outside the frame. Seems odd… I’ll suggest the reason may not lie with bike designers, but with an impending release (speculation…) of an alternative means of connecting controls to derailleurs that will integrate more easily. If this were the case, and the frame designers only designed for the current wiring harness, they’d be caught with their pants at their ankles for any new wiring development from Shimano. To their credit, Trek is the only manufacturer that has flown above all this with their excellent cable integration on the new Speed Concept bikes.

The Felt DA has a small segment of the wires outside the frame. It isn’t perfect, but it isn’t a complete disaster either, and it could have forward design implications we aren’t privy to yet. Still, this is one of few places the new DA gives something up.

2011 Felt DA Di2
Assembly and wiring of the Di2 harness through the frame is relatively straightforward with an access panel and battery mount under the bottom bracket. The battery is covered by the weather proof housing and the access panel also uses a small carbon fiber cover.

The Main Triangle: Narrow is Aero.
Moving back the bike we further encounter how narrow the frame members are. The downtube is bladed, airfoil shape. Very, very bladed. It is quite narrow, 28 millimeters wide over most of its length. There is no bottle mount on the down tube but there is a single seat tube bottle mount, the most aerodynamic position for a bottle mount. You’ll need to go to a handlebar mount hydration system for longer rides and Ironman distance. No problem, as the well conceived front mount systems actually improve bicycle/rider aerodynamics. The top tube has a vaguely triangular orientation. The combination seems to exert an influence on ride quality which I’ll cover in the road test paragraphs of this review in a moment.

2011 Felt DA Di2
A look at the seat tube reveals the bottle mount and the curvature of the seat tube. This is a highly evolved version of the new DA. Felt mentioned more than five versions were tested prior to the adaptation of the current frame.

Felt went through a number of iterations of the new DA shape in development. Early versions used by the Garmin team had a curvy down tube. The version that evolved to sales floors is more than five versions removed from the original concept. Felt says each of these steps constitutes an evolution of improvements, and that the finished bike is tangibly better than early prototype versions used by Garmin.

The bottom bracket is BB30 which opens up the capability, via adapters, to use almost any bottom bracket configuration on this frameset. The bottom bracket that comes with the bike uses ceramic bearings from Enduro.

What’s that Bump?
There is a “bulge” in front of the bottom bracket shell that houses the Di2 battery. This fairing is a “weather seal” (that’s for the UCI…) that “protects” the Di2 battery. What it does tangibly do is improve high yaw angle aerodynamics at the crankset according to Felt. Felt claims this shields the rotating chainrings from crosswinds. The cover is easy to use and looks like an ECM or sensor bulge on a fighter plane. The housing attaches with two bolts. The fit on the housing to the frame is quite good if you compare it to first generation Cervelo P4 standards with their attempt at integrating the water bottle. Other configurations of the Felt DA have the capability to mount the battery behind the seatpost for UCI approval. I like the appearance of the housing more than an exposed battery.

2011 Felt DA Di2
The housing over the Di2 battery attaches with two small bolts and is claimed to provide an aerodynamic benefit at high yaw angles.

Speaking of integration we move back to the rear brake, a proprietary design that is mounted inside a recessed section of the bottom bracket/chain stay area. The rear brake does accommodate a wide-aero wheel like Zipp Firecrest. The rear wheel that comes with the Felt DA is a standard (non-Firecrest) 1080 deep section wheel. Felt told us that is because there is no 1080 Firecrest yet. Rear brake performance is extremely good, the best of the integrated, proprietary systems I’ve ridden. It is not soft, mushy or tentative. Set up requires a little attention but is better than most of the other integrated rear brakes in that, once it is adjusted, it has a lot of stopping power.

Another thoughtful move by Felt is the wheels have relatively neutral graphics- they aren’t specifically color coordinated to this bike. They maintain good resale value, an important consideration for dealers and consumers.

Further Back: A Great Seatpost/Clamp and Closely Oriented Rear Wheel.
Moving up the seat tube with its vaguely curved shape, wrapping the leading edge of the rear wheel, we get to a truly adjustable and relatively conventional seatpost. Felt: Thank you! This bike is a breeze to pack in a flight case. The seat clamp design is excellent and works on the first try. No slipping. No problems. Scott and Trek and Cervelo have had problems with slipping posts on superbike designs. Several different geometry seatposts will be available to induce various effective seat tube angles. The binder assembly is flush with the top tube and trouble free.

2011 Felt DA Di2
The seatpost stays put when you torque it to spec. No slipping on our test bike. The seat stays are aerodynamically seperate from the rear wheel for claimed better aerodynamics.

The seat tube of the frame does ride close to the wheel as does the down tube of the frame with the front wheel. This seems to contradict the “open aero” doctrine applied to the proximity of the seat stays and fork blades from the sides of the wheel, but Felt assures us it does not. There is no way for us to verify or debunk this.

The Stock Saddle: It Works!
The saddle spec struck me as weird initially, until I rode it. The Prologo Nago TTR TT saddle is a short nosed, 26 cm long saddle with only 5 cm of saddle in front of the carbon fiber rails. What? We all know that 30 cm long triathlon specific saddles like the Profile Tri Stryke and Fizik Arione Tri are longer, not shorter than a standard 27cm road saddle. I thought this saddle was a mistake. Then I rode it. The Nago TTR has little plastic “ribs” or grippers on top of it. They hold you in place fore/aft. In the real world this saddle is a good triathlon saddle for a couple reasons. Firstly, most triathletes have saddle discomfort at the nose of the saddle. One fix: remove most of the nose. The ISM Adamo and some Cobb Cycling saddles work this way. The problem with the ISM’s is that, although they are short, the two “horns” are very wide and irritate the inside of a rider’s thighs. This Prologo Nago seems to moderate the conflict that previously existed between short and wide saddles by being short and moderately narrow- but still tolerable.

A second benefit of this shorter saddle is climbing out of the saddle. On a steep angle triathlon bike a 30 cm saddle hits you between the thighs when you climb out of the saddle. Annoying. The Nago does not. It climbs out of the saddle superbly. Felt came out of left field with this saddle spec but it really works great. I’d be thrilled to keep this saddle on the bike.

2011 Felt DA Di2
I initially did not understand how the Nago TTR saddle may work but after a couple rides I was surprised to learn it makes a very credible triathlon saddle.

At the back of the bike the seat stays mimic the fork aerodynamic theme by providing “breathing room” between the rear wheel and the seat stays. The chain stays are very deep contributing to an overall excellent rear end with rear-facing horizontal dropouts with internal adjuster screws.

On some new aerodynamic frames there have been concerns about compatibility with wider aero race wheels such as the Zipp Firecrest, newer HED wheels and Zipp Sub-9 disk wheel. We fitted a rear Zipp Sub-9 tubular disk wheel to a 2011 Felt DA and found there was adequate clearance for both the brakes and the chainstays. The rear wheel does flex laterally under very hard, out of the saddle efforts, but it is unlikely there would be regular or significant contact except under extreme circumstances such as a very heavy rider.

The rear derailleur hanger on the 2011 Felt DA is a fixed hanger that is rather robust. It is unlikely to bend easily and impressed us as being durable enough for normal racing use, which includes normal flight-casing and the occasional tip-over in a transition area.

2011 Felt Di2 DA Tri Bike
Left: We tested the rear clearances of the brakes and the chainstays with the wide section, aerodynamic Zipp Sub-9 disk wheel and found adequate clearance. Right: The rear derailleur hanger is fixed to the dropout and is relatively robust providing good durability and strong, repeatable shift performance.

What About the Di2?
Shimano Dura-Ace Di2 is the best triathlon component group becasue of the multiple location controls. Period. You already know this is a Di2 equipped bike. When I asked Felt’s Dave Koesel, Road Brand Manager, if we would see further expansion and acceptance of electro-mechanically actuated drive trains he was emphatic: “Yes, absolutely.” Shimano has already announced the release of a lower cost Di2 ensemble. Is Di2 an advantage? One word: Absolutely.

2011 Felt DA Di2
The Shimano Di2 ensemble provides a tangible performance advantage to triathletes, especially on a course where a lot of shifting is required.

You will have a faster bike split since you can shift from either the base bars of the aerobars and you will never miss a shift. With Di2 you will always have the correct gear for the terrain and conditions. Shifting from the base bars and the aerobars means cornering and climbing is easier. It is simply a fantastic component group. With rumors of further improvement and integration from Shimano to work with existing frames early adopters likely will not be punished as new Di2 components emerge.

How Does it Ride?
The previous versions of the Felt DA were too flexible for me. I rode a Felt B2 with the stiffer lay up as a result. Forget that. This new DA is entirely different not only in appearance and spec but most tangibly in ride quality. I seldom recommend test rides but a few pedal strokes on this new version is all it takes to differentiate the new DA from any previous version.

2011 Felt DA Di2
At speed the bike is stable, the frame stiffness provides excellent cornering and climbing.

The DA is the best riding of the new generation triathlon bikes I’ve been on. It is much stiffer than previous DAs and climbs savagely out of the saddle. The front is unerringly connected to the back: long and stable. Put your elbows on the pads, touch the button to find the perfect gear against the Mumuku headwinds and point the thing toward Hawi. It will track a laser-straight line with little need for steering input. Reaching for a bottle or a snack from the aero position? No problem. It’s on autopilot. Hit a steep climb at the beginning of Tiger’s Back at the Laguna Phuket Triathlon in Thailand? No problem; out of the saddle, touch your Di2 controller to find the right gear and swing the stiff monster back and forth while the Prologo saddle misses the back of your thighs by a country mile. I get to ride a lot of fantastic bikes in my role as Editor of TriSports University. This is the triathlon bike I want. This is so much nicer than any previous Felt DA. Simply put: Felt nailed this one. It’s good to see a super bike that is truly super.

2011 Felt DA Di2
Because the front end is now so "connected" to the rear end the bike descends with authority and control. The front end geometry adds stability and the lateral stiffness provides control.

How Much? $12,499.00
At $12,499.00 this is an expensive bike. When I asked Felt’s Dave Koesel about the price he said it represents the highest end commonly available components across the industry. While it seems a stretch to call a $12,499 bike a good “value” there is justification for the price with the component spec and the frame re-design. The Carroll Shelby cliché comes to mind, “Speed costs money. How fast do you want to go?” The crux here is that the combination of the new DA frame, Zipp wheels, Devox cockpit, Di2 components and some attention to details like good brakes and a nice saddle mean you likely will be faster on this bike compared to something else if it fits you correctly. There are tengible advantages here.

“The new Felt DA is the bar-raiser in the superbike category for 2011.”

The Verdict.
I review “superbikes” every month. Some of the reviews make the cut, some hit the cutting room floor along with the bike. I’ve been reviewing bikes since the late 1980’s. There are a few stand out bikes: The Softrides, the first Quintana Roo Kilo, The Kestrel 4000, The Cervelo P3. Game changers. They owned their categories and raised the bar. The new Felt DA is the bar-raiser in the superbike category for 2011. Nearly every superbike design is characterized by a set of quirky limitations or little oddments or idiosyncrasies. The DA is refreshingly devoid of those “catches”. You can ride it, flight case it, race it and work on it. Felt took a long, circuitous route to get to this newest version of the DA. It is the culmination of many lessons learned in previous designs. Felt learned well from previous versions because the new 2011 Felt DA is truly an exceptional bike that is as close to perfect as any bike over the previous 20 years in triathlon.

2011 Felt DA Di2
Felts new 2011 DA is an ambitious project that delivers as the easiest to use, most practical and one of the best riding of the new generation of triathlon superbikes.