Reviewed: Felt Breed Advanced GRX 820 Gravel Bike

Felt has a long history with drop bar offroad racing. In 2011, the company signed U.S. cyclocross star Ryan Trebon. In 2014, the company had as many as five cyclocross models, including a dedicated singlespeed model called the Breed. The company sponsored Wout van Aert during his 2018 Cyclocross Worlds-winning campaign (see our Van Aert bike profile) and his Crelan-Charles team. Today, Felt’s drop-bar offroad involvement is probably most known for its sponsorship of the Felt United gravel team, including marginal gains legend Dylan Johnson.

We’ve been riding the latest Breed model. The Breed had now jumped the course tape to venture more towards gravel, something we’ve seen with other companies including Specialized with its Crux and Santa Cruz with its Stigmata, so much so that Tobin Ortenblad continues to race a discontinued model. Cyclocross purists need not fret, as the company still has two cyclocross-specific FX models, albeit dressed with gravel cranksets with 46/30 chainrings. There’s a GRX 11-speed model for $3199 and a GRX 12-speed model for $2999.

Felt Bicycles is named after founder Jim Felt who welded custom bicycles for triathletes while working as a motocross mechanic. Felt started Felt Bicycles in 1991. Jim Felt had his hand in the company until 2017 when Rossignol bought it. The company is now in the hands of Pierer Mobility This will give the brand stability and the ability to continue innovation.

Felt has three gravel bikes in the lineup, two versions of the Breed for fast gravel riding and racing, and one for adventure gravel, the Broam.

Felt Breed Carbon Advanced GRX 820 Specs:

We have a race-oriented carbon frame version of the Felt Breed with Shimano GRX 820 as the name implies. In 2024 several gravel race stars @dylanjawnson, @adamroberge, and @danni_shrosbee all race the 2024 Lifetime Grandprix gravel series aboard a Felt Breed Advanced carbon bike. You could not ask for better representation in the gravel race scene, and that certainly gives this bike some credibility.

Our review model is a top-end gravel bike from Felt. The Breed Carbon Advanced GRx 820 is ready to race with an out-of-the-box weight of 9kg, or 19.85lb without pedals and with tubes in the tires. Our review sample is size L or “56”, with a 57cm effective top tube and a 53cm seat tube. A 71-degree angle to the 145mm tall head tube combined with a 50mm fork offset calculated to a 69mm trail figure, or 66mm of mechanical trail. All this yields a 591mm stack and 389mm reach. Out back, 43cm chainstays and a 74-degree seat tube angle contribute to rear tire clearance. The BB drop is 72mm and the wheelbase is 104.5mm.

The frame is a carbon monocoque with a matching all-carbon fork. The head and downtube junction is massive with an area behind the head tube that is like a fairing. The down tube has a squared cross section that I cannot get my hand around. If you use this bike to race cyclocross, picking up the bike via the downtube will require some grip practice.  Thankfully, the control lines do not run through the headtube, but enter the downtube in a more ‘traditional’ fashion. Those control lines run through the T47 bottom bracket shell to their respective exit points at the chain stays or behind the bottom bracket shell for the front derailleur cable.

The T47 threaded bottom bracket shell is an external/internal hybrid. This means on the drive side the bearing cup is external and is internal on the non-drive side. This offers more crank space on the drive side, but can still have a wide bottom bracket stance for chainstay bracing and tire clearance. I like this idea. In addition to eliminating chainring and chain line restrictions, if your chain derails inboard of the chainring, there is enough space so it won’t wedge itself between the crank and frame, potentially damaging the carbon. The chainline measures standard road spacing (47.5mm) pushing out to almost 50mm with the GRx crank.

After a few months of riding and a wash, the bottom bracket developed some creaking, but regreasing and tightening the cups seemed to address the noise.

The seat tube has a wedge-style seatpost clamp that is nicely secured in place with a screw. Many frames do not have this feature and the wedge falls into the frame with seatpost removal, which is a maintenance nuisance.

The Breed Carbon has Felt’s Taperlock vibration damping sleeve for the 27.2mm diameter carbon shaft seat post (with an aluminum 2-bolt micro-adjust clamp). The sleeve is similar to the Iso Flex system used in the Pivot Vault. Remove the sleeve and a 30.9mm post fits. The frame is compatible with an internally routed dropper post where 30.9mm is more readily available, but if you want a little bit of vibration damping you can use the sleeve with a 27.2mm internal dropper. A rubber cap covers the wedge and will stretch to fit around a 30.9mm seatpost.

Thin seatstays do not have a bridge but also do not have a low mount to the seat tube that is presently popular. This gives a wide stance, so tire clearance and mud accumulation are not issues here. Offset chainstays with the driveside a bit lower behind the bottom bracket shell yields the best combination of chaining and tire clearance. There is no mud shelf behind the bottom bracket.

Felt specifies that the maximum tire clearance for the Breed Advanced is 700C X 50mm  (29″ X 2.0″) or 650B X 2.0″ if you like smaller wheels. Curiously, the same maximum tire width does not increase for the smaller diameter 650B wheelset, but you can see in the photos that the chainstay spacing is not wider further behind the bottom bracket.

Dylan Johnson famously ran 2.2″ mountain bike tires for his 10th-place finish in the 2024 Unbound Gravel.

 

On the bottom side of the downtube is a rubberized skid plate that protects it and the bottom bracket should you kick up a rock with the front tire or if you hit something you were trying to ride over. The drive side chainstay also has a rubber cover for protection from a slapping chain.

The Felt Breed Carbon has ample mounting points for bottles  (a double on top of the downtube) and a top tube bag mount. There are no barnacles on the fork blades and no fender or rack mounts. Our frame is a pleasant teal blue with a contrasting fork color that almost makes the fork look mismatched. The rear dropouts are SRAM UDH compatible with 142mm X 12mm through axle spacing. The UDH derailleur hanger for non-SRAM transmission derailleurs is inboard of the frame, which makes it incompatible with some older derailleur hanger alignment tools. This is not unique to the Felt Breed Advanced.

The 12mm through axles include one removable quick-release type handle with a 6mm hex end. You can leave this on one wheel so it is handy if you need to remove a wheel. That avoids digging through your repair kit if it’s something simple, or remove the lever to improve your CDa or save an ounce!

The Build: Shimano GRX 820

As the model name implies, the Felt Breed Advanced GRX 820 has a Shimano GRX 820 12-speed component group. This includes the double chainring GRX 820 crankset with a 48/31 chainring combination and 172.2mm crankarm length, an RD RX 820 rear derailleur, and an FD RX 820 front derailleur. ST RX 820 brake shift levers and Br RX 820 brake calipers complete this bike’s GRX 820 component group. The 11-34 cassette is a Shimano Ultegra M8101 and the chain is a CN M8100 XT 12-speed. MT 800 rotors, 140mm rear native, and 160mm front complete the Shimano component list.

The asymmetric bottom bracket is made by Token, a Taiwanese company that started with headset and bottom brackets with precision bearings.

To complete the build, an aluminum -7 degree stem, 100mm long for our 54cm size, paired with a 44cm wide aluminum handlebar with a few degrees of back sweep and a mild flare to the drops. Both the bar and stem are Devox branded. The 27.2mm diameter seatpost is a carbon tube with an aluminum 2-bolt head.  The saddle is a Prologo Dimension NDR with chromoly rails that Prologo labels T4.0.

Spinning on Reynolds G700 Wheels:

The wheels are a Reynolds G700 carbon rim gravel set. Felt says this wheelset is custom for them, but I could not determine what makes them different from the G700 wheels you can buy from Reynolds. Felt brand managers Zapata Espinoza and Karlo Dgallegos clarified that the G700 wheels are a collaboration with Felt from the pre-pandemic design phase of the Breed, and now are available as a Reynolds aftermarket wheelset.

The carbon rim is 26mm deep and 30mm wide externally with a 25mm internal width and a hookless profile. 24 straight pull Sapim Sprint double-butted spokes connect to Ringle branded hubs with X2 lacing. Spokes are interlaced at the crossing point, something discussed in the Logos Components Epoche wheel review.

Vittoria Terrano Dry Graphene 2.0 tires labeled 38mm measure 40.5mm on the Reynolds G700 wheels. They came with tubes but we converted easily to tubeless on the pre-taped wheels. These have a directional fish scale-like center section with a decent row of side knobs.

The Felt Breed Carbon Advanced GRX 820 Gravel Bike Ride:

To remain objective, I did not review the bike’s geometry and rode it as it came out of the box with tubes in the tires. The Felt Breed Advanced suits gravel racing or fast gravel riding. From the road and cyclocross perspective, the Felt Breed Advanced feels immediately familiar with good road manners. It is not a super fast handler but is nimble enough. It is smooth and stable on paved roads and fire roads, falling into your chosen line with just a lean, like a good long-distance road bike.

The Felt Breed Advanced’s geometry supports my perceptions from initial rides with 43cm long chainstays, a 625mm front center, 104.5cm wheelbase, and a low 7.2mm bottom bracket drop. The bike certainly has a “long and low” feeling compared to an old cyclocross bike, especially when you first swing your leg over and straddle the bike.

The mild road manners of the Felt Breed Advanced transfer well to less smooth terrain. Add fist-sized rocks, some small steps and roots and the Felt Breed Advanced will hold its line even as the rock tries to divert the fork. The longer chainstays make it easy to stay balanced between the wheels and let the rear end follow down the line easily. This stability is confidence-inspiring even when those fist-sized rocks are loose, giving a dynamic surface.

Gravel bikes are evolving almost as fast as mountain bikes did in the early 1990s, with geometry tweaks, increasing tire clearance, and renewed experimentation with suspension. Gravel bikes started with the adaptation of cyclocross bikes for long-format racing and adventure in the cyclocross off-season. As mixed terrain riding gains popularity, evolution is a divergence between fast gravel racing and adventure gravel riding. The line between gravel and cross-country mountain biking is beginning to blur.

Felt is quite progressive, offering 50mm tire clearance on a gravel racing bike. It pays off since many of the top 2024 gravel racers run tires that wide. Only a couple of years ago, 38mm-40mm was the racing standard with some outliers running 42mm. 650B wheels allowed wide 47mm tires in the frames at the time for the adventure rider.

Up front, the fork features a 420mm axle-to-crown length. This extra height makes the bike geometry ready for one of the short 30mm travel forks for gravel. I like underbiking, so eschew the extra weight and complexity of extra rider suspension, relying solely on the frame, stock components and tires. I rode the Felt Breed Advanced primarily with the stock Vittoria Terrano Dry 38 tires set up tubeless without inserts. The tires measure 40.5mm on the Reynolds G700 wheels but changed to some wider rubber primarily to see the maximum tire clearance. Thankfully, 50mm tires fit easily into the Breed Advanced and, and as proven by Dylan Johnson at the 2024 Unbound Gravel 200, a 2.2″ mountain bike tire (56mm) can fit if it’s not too knobby. This is beyond Felt’s recommendation and according to ISO standards requires a minimum 4mm clearance between the frame and the widest part of the tire for various reasons.

Adding 50mm wide tires certainly adds a modicum of traction, smoothness and confidence off-road, but at the consequence of over 100 grams per tire compared to an already heavy for its size Vittoria Terrano Dry. The wheel weight is palpable, and you have to decide what is important to you given the terrain you ride in. It is proven that smoother is faster, and wider is smoother in many conditions. So wider is faster, at least sometimes.

Vittoria does not have the Terrano Dry 700C X 38mm tire listed on its website. The 700C X 40mm replaces it, so kudos to Vittoria for more accurate labeling. The Terrano Dry tread seems good for most dry conditions I’ve run across. The fish scale center is smooth and quiet on pavement and provides good grip off-road if the surface is packed, or rocky. The side knobs are close enough to the center to engage with only a slight lean and seem to hook up quite well on looser surfaces. The tires perform worst on kitty litter and wet conditions where the center section is too smooth for good traction. The fish scales quickly become smooth with wear and lose offroad grip after only a couple of hundred miles of pavement riding. The tire becomes no different from other smooth center gravel tires such as the WTB Byway. After a few hundred offroad miles, the rear tire’s fish scales are largely missing.

The included carbon-shaft seatpost, paired with the TaperLoc insert, flexes visibly when you push on it or if you bounce on the saddle. This certainly adds palpable seated plushness. For a short period, I replaced the stock post with a dropper post and immediately felt the loss of seated compliance, though I gained downhill confidence with the seat lowered over steep or technical sections. Even without the dropper post, the long front center makes descending steep sections reasonable.

Gravel or #ShortTrackGravel?

Despite its long wheelbase, the Felt Breed Advanced is nimble enough for most endeavors, including traditional flowy, fast cyclocross (#shorttrackgravel) courses. I liked the balance and stability on the small steps on a cyclocross race track and enjoyed the muted damping of the big tires and seatpost flexing over bumpy grass and washboard. If you try to pedal through on a steep ride-up with a lip at the top you’ll likely strike a pedal with the Felt Breed Advanced.  Half a centimeter lower for the bottom bracket drop is not that much, but combined with the long wheelbase, the bottom bracket is closer to the apex of the crest. Nicely, the power transfer efficiency with The Breed Advanced allows good acceleration for a fast run-in to get over the lip without pedaling. It’s not snappy enough to beat a competitor to the apex of a turn in tight quarters, but excellent to break away with a hard acceleration on a steep climb of a long gravel race, and even for the sprint to the line. It’s also worth noting, that with bigger mountain bike tires, your bottom bracket height will be closer to a more traditional cyclocross bike.

Portaging the bike via suitcase or shoulder is natural since the main triangle is large and the underside of the arced top tube is smooth. If you habitually pick up the bike via the large cross-section downtube, it is an awkward handful for my medium-sized hands.

Felt Breed: Built for Speed Over Adventure

The Felt Breed Advanced is definitely for fast gravel riders. There are no mudguard or rack mounts, but enough mounting points for hydration and day-ride accessories such as small nutrition or tool bags. Geometry is more like a road bike than a mountain bike. The 140mm native rear brake rotor is an old-school nod to the race orientation of the bike.

The GRx 820 version we have to ride and review has a 31 x 34 or 1:0.9 low gear (24.6 gear inches) and a 48 X 11, 1:4.4 (117.8 gear inches) top end worthy of a gravel pro, definitely not a gear choice for someone hauling a load over long distances off-road. Rather, the close ratio steps of the double chainring setup is for fast and light day riding. Shimano has the front shifting dialed, so I never dropped a chain or missed a shift going between the two chainrings. Gaining one extra cog on the 12-speed 11-34 cassette compared to the 11-speed version was not that noticeable to me, though there is a smaller step between cogs somewhere in the range. The cassette cogs and chains are narrower, and in our experience, that might cause the shifting to suffer in sloppy conditions.

I think the 44cm bars are a bit wide for the size of the frame, but that is a matter of taste. Dylan Johnson rides 36cm bars or narrower, but he’s on the extreme end. Narrower bars for aerodynamics and ergonomics make sense, whereas wide handlebars for torquing through technical terrain are not a match for this bike, in my opinion.

Felt Breed Gravel Bike: The Verdict

The Felt Breed Advanced is not as slack or long as a bike like the Nukeproof Digger or Ari (Fezzari) Shafer, but not as steep or short as a traditional dedicated cyclocross race bike such as the Bombtrack Tension C or Trek Boone. In my opinion, the Felt Breed Advanced is the true evolution of the gravel race bike. It hits the mark with clearance for 700C X 50mm tires, stable geometry that is lively and agile enough to feel racey, and good bump compliance via the seatpost and perhaps some carbon layup choices.

The Felt Breed Advanced GRX requires no upgrades at the onset. The GRX 820 12 Speed drivetrain spec offers a great gear range and performs flawlessly in conditions during the mostly dry test rides. The Reynolds wheelset, though not the lightest with a claimed weight of 1545 grams, is durable. The Vittoria Terrano Dry tires are a good choice for a lot of terrain you might encounter. Tires, then the wheels might be the place for upgrades, but the included set is a solid choice.

Competing bikes include the Trek Checkpoint with similar tire clearance and geometry, and the new Trek Checkmate gravel race bike has narrower tire limits. The Specialized Crux is another bike in the same category with a maximum tire clearance of 47mm and a less slack front end. The Cervelo Aspero and Factor Ostro gravel bikes have road bike-like geometry and 45mm maximum tire clearance. In terms of tire clearance, the Breed’s biggest competitor might be the ultra-versatile, barnacle-equipped Rocky Mountain Solo we’ve reviewed favorably.

There is no one bike to rule them all, but if you’re looking for a mixed-terrain bike for fast day rides with some racing pedigree, I think the Felt Breed Advanced has the right attributes for a modern gravel race bike and deserves strong consideration.

Is $4499 outside your budget? The $2999 GRX 610 model is worth a look. It features the same frame and many of the same components, including cockpit and derailleurs. You don’t get the carbon Reynolds wheels and have a GRX 610 crankset and levers, Shimano 105 chain and cassette (instead of Ultegra) and GRX 400 brakes. Will you notice the difference? Perhaps in wheel weight but maybe not in the parts.

Felt Breed Carbon Advanced GRX 820 Gravel Bike Specifications:

MSRP: USD 4499 as tested
Frame: Felt UHC 1.0 carbon monocoque 12 X 142mm through axle, 68mm T47 BB, SRAM UDH compatible
Fork: All Carbon Disc, 50mm offset, 420mm axle to crown, 2 X 100 through axle
Weight: 19.8 pounds, as tested with no pedals; 13.0 lbs without wheels or pedals
Shifters: Shimano GRX RX 820 12-speed, RD RX 820, FD RX 820
Crankset: Shimano GRX 820 48 X 31, 172.5mm arm
Brakes: Shimano GRX 820 flat mount calipers, Shimano MT 800 rotors 160mm front and 140mm rear
Cockpit: Devox 10cm stem, Devox 44cm aluminum handlebar,  back sweep and flare
Seatpost: Felt carbon with aluminum 2 bolt clamp, 27.2mm diameter
Saddle: Prologo Dimension NDR, steel rails
Wheels: Reynolds G700 25mm inner width carbon, 24 spokes
Tires:  Vittoria Terrano Dry, 700C X 38mm (actual 40mm)
Warranty: Limited, against manufacturer defects, to the original owner
Country of origin: Taiwan
More info: Feltbicycles.com