When wooing former American national cyclo-cross champion Ryan Trebon (L&T Sports), Felt had an ace card – a professional quality carbon fiber 'cross bike, built with lessons learned producing bikes for the Garmin road team. All they had to do was make it in a size large enough for the 6ft 5in (1.96m) rider. Now that 63cm size is available to you, too – but there's plenty more to recommend the F3X than just its generous sizing range.
Ride & handling: All business
Some carbon cyclo-cross bikes have the ability to 'carve' a line through rough and bumpy terrain. The F3X isn't one of them. Instead it's stiff and built with a firm, European-style emphasis on power transfer over comfort. It's a tool to go fast on.
If you're having a good day, it puts all of your power down to the ground with a snap. But if you're having a bad day, it won't hold your hand and help you fake it. With this bike, you have but one option – ride it aggressively and capitalize on its power transfer, because if you don't you're going to come away feeling pretty beat up, both physically and mentally.
This stiffness has been carried over from the road bikes Felt developed for the Garmin team, and it benefits both the power transfer and handling precision of the F3X greatly. As a result, we've found it a really good bike for cyclo-cross training and racing. However, it's not a machine that'll do double duty as an all-day dirt road bike – after a couple of hours in the saddle the sport-inspired ride starts to wear on you.
We found the front end plenty stiff, with point-and-shoot handling
The frame provides a solid foundation for producing power and the front-end is just as solid. On a smooth track this allows you to put the front wheel where you want it. But when the track gets really bumpy – as we experienced racing the fourth round of the Exergy US Gran Prix of Cyclo-cross in Fort Collins, Colorado – the stiff front end gets bounced around.
There are times when you just have to hang on and hope you make it through. If Felt could mellow the fore-aft stiffness slightly without affecting the fork's resistance to chatter – we experienced no chatter when using either wide-profile or linear-pull style brakes – they'd be onto a winner.
With all of this talk of stiffness, we were surprised by something else that came up in our time on the Felt: a slight twitchiness on high-speed road descents. We haven't managed to work out what causes this, as Felt's geometry is within millimeters of both Cannondale and Trek's: 72° head angle, 73.5° seat angle, 43cm chainstays, 65mm bottom bracket drop, 45mm fork offset (rake) and 1,007mm wheelbase.
Despite these niggles, if you're a powerhouse like Trebon – at the first round of the 2011 USGP he averaged 472 watts, with plenty of time at 0 watts – or a rider who doesn't need to be coddled around the race course, you're going to like Felt's new rig. If you're over 6ft this is going to be one of your best options for a professionally featured carbon ’cross bike, and definitely worth a test ride. More 'delicate' riders, on the other hand, will likely prefer one of the more comfortable, carving ’cross bikes out there.
We put the Felt F3X through its paces at the 2011 US Gran Prix of Cyclo-cross in Fort Collins, Colorado
Frame & fork: All carbon from Felt
Felt have thrown their considerable carbon construction know-how at cyclo-cross for the first time and the end result is impressive. Their Modular Monocoque Construction (multi-piece molding) and InsideOut (use of a polyurethane inner mold) techniques allow them to precisely place carbon plies and regulate resin within the molding process, and their UHC Performance carbon is a T-700 blend that's on-par with anything else at the top end of the market.
The F3X frame weighs 1,180g (53cm size with seat clamp, derailleur hanger and bottle bolts) and the Felt CXR UHC Advanced fork is 453g. Contemporary design features include a tapered 1.125in to 1.5in head tube and standard (not press-fit) BB30 bottom bracket. The fork uses a lesser modulus of carbon fiber than the frame, for better impact protection and vibration damping. It has a full-carbon steerer, crown and legs, with forged alloy dropouts.
Cyclo-cross features are good, too. The underside of the top tube is flattened and comfortable on the shoulder. Mud clearance is adequate rather than outstanding but Felt make up for this with a bridgeless chainstay/bottom bracket connection that's molded with smooth lines and thin shapes to prevent the buildup of mud and aid in shedding it. The headtube length is right in the middle of the road, at 130mm for our 53cm, and offers riders the ability to go high or low; whichever is needed for proper fit.
We love the look of the convex curved seatstays, though the back end still proved firm
Equipment: Two major misses, but overall an elite level pick
Overall, Felt's product managers have done an excellent job of providing performance at a reasonable price. All of the supporting components are 'right' for cyclo-cross, meaning alloy and workhorse, and the bar bend and saddle are comfortable. To race the second-tier F3X at elite level, we only needed change two things: the TRP EuroX brakes, which lack power, and the wheels, which we replaced with tubulars for their superior comfort and traction.
We have to say, though, that the full SRAM Red groupset is overkill for cyclo-cross. While we appreciated the ZeroLoss rear shifter feel and the precision it provides, the cost of including the transmission has forced a major drivetrain concession – a cold forged S300 BB30 crankset. This light-ish – 759g – alloy setup flexes noticeably, even when compared to a Rival OCT (hollow forged) alloy GXP crank.
We'd be happier with an all-Force transmission, or even a Rival drivetrain mated to SRAM's Force BB30 crank. Thankfully, Felt have got the chainring ratio right, with a 46-tooth outer ring paired to a 38-tooth inner ring, proving that their product managers are in tune with what's useful out on the cyclo-cross course – if the hill is steep enough for a 36-tooth inner ring, put the darn bike on your shoulder.
The mix-and-match drivetrain pairs S300 cranks with a SRAM Force front derailleur and Black Red rear derailleur
The other dog of the F3X's spec is the TRP EuroX cantilever brakes. While light and offering massive rim clearance on muddy days, these are seriously short on power. After a handful of training rides, we swapped to TRP's CX9 linear-pull brake and were much happier. We'd recommend ditching the EuroXs and replacing them with TRP's CR950 cantilevers or new linear-pull TRP CX8.4s (which are said to better match the cable pull ratio of a SRAM lever than the CX9), or the current benchmark cantis, Avid's Shorty Ultimates.
It's good to see Fulcrum's Racing 5 CX clinchers on the spec list – wheels are an area many manufacturers skimp on in order to better the final price or bottom line. They're designed for cyclo-cross, with extra seals in the hubs for better durability, and are a solid set, if slightly heavy. The Vittoria Cross XG 32mm folding tires are adequate for training but they're fairly tall and tend to fold over at lower pressures (around 30psi). Their 'old school' chevron tread also lacks the traction of more contemporary designs. Racers will likely want to upgrade to tubular wheels to maximize performance.
Fulcrum's Racing 5 CX proved solid, albeit heavy; in all, a good training wheelset