The exciting LS Gravel is Factor's true leap into the gravel race zone with the desire to build a lightweight frameset with perfectly balanced geometry, stiffness to deliver voracious acceleration and climbing performance, while diverging from more of the do-it-all options and quasi-race designs. The balance of comfort and performance being crucial to gravel success, LS offers the correct stiffness for aggressive riding on harsh terrain to break free from the pack without beating on the rider. The LS has been optimized around 40-43 mm tires (43 max). We built a size run of well-equipped Shimano GRX-815/810 Di2 complete bikes for those who prize speed and podiums over satisfaction of a long grind.

Each size of the LS Gravel has its own specific lay-up and definitive tube sizes. Factor has mastered the processes of Computer Fluid Dynamics (CFD) and frame laminate design with it's Fibersim optimization program, using the only the absolutely necessary types and amounts of carbon fiber and resin for each frame. Each LS is built with Factor's EM2 RGicarbon system, employs various amounts of three carbon fiber types: Standard Modulus, Medium Modulus, and the costly and difficult to work with High Modulus Pitch Fiber. Each is applied to it's greatest effect, in accordance with the desired properties of each frame section or tube. Due to the challenges and costs, Pitch fiber is rarely used except at the top-end of the bike world. Factor knows the process and material well, and uses Pitch fiber to it's greatest effect. That exacting process, zero waste, highly informed engineering, and optimal materials combine to deliver a 950 gram gravel race frame that responds like nothing else.

Avoiding trade-offs associated with accommodating the larger tire sizes needed by gravel racers, the geometry of the LS is optimized to ensure exceptionally reactive handling. A 420mm chainstay length is the sweet spot for gravel race bikes, and Factor has managed this while keeping more road-style seattube angles per size. The fork trail varies slightly by size but is between 59-61mm, with all sizes utilizing a 50mm fork offset Headtube angles are only slightly slacker than road norms. The slight triangle cut out offers more space in the rear for the tires, while the frameset itself maintains the O2 style sloping toptube. A 76mm BB drop reflects the added height of the tires. Conceptually, the downtube has a little more curve off the headtube, increasing the clearance there. The end result is a quicker handling bike that retains some stability, but reflects the true race nature of the LS Gravel Frameset design.

Many other frame features that Factor believes strongly in have moved from the O2 to the LS. You'll find the asymmetric bottom bracket system and vertically oversized chainstays. Their pencil shaped chainstays- so effective at mitigating frame buzz from the rear dropouts, have a kinked design that accommodates the tire size, and adds a bit more lateral stiffness along with vertical compliance. The sleek 1-1/8" - 1-3/8" tapered fork is specific to the LS, with a wider crown to leg transition and more clearance from axle to crown (395mm) without adding much overall fork/headtube height- again the racer's preference. On the rear dropouts, just above and behind the axle, hidden lower fender mounts have been added for those times you need one. Along with the inner triangle down and seat tube bottle cage bosses, a third was added under the downtube-. A set of toptube Bento-box style bosses sit behind the headtube.

As expected the disc brake frameset features the Flat Mount standard for the disc calipers (140-160mm rotors), 12/100mm front and 12/142mm rear threaded thru-axles, an integrated chainsuck guard, removable braze-on style front derailleur mount, Factor's hidden and reliable integrated seatpost fastening wedge system for a 27.2mm diameter round seatpost. A standard headset for the tapered fork/headtube is included, as are the thru-axles, and replaceable rear dropout. The frame can accommodate several types of slim/sleek strap-down bike bags for long, isolated events or rides without feeling unbalanced.

The LS Gravel delivers a gravel racing experience road racers will gravitate to. Even some of the best gravel race options tend to feel too stable, without the handling capabilities desired by many. There is a balance needed there, and for Factor they came down on the more reactive side without going too far. It becomes easier to track in straight lines off the rear wheel, while allowing the front to lift and ride over loose or rocky material. Plus, when the track is smoother, or you hit pavement, the LS will handle more like a road bike.

The complete build spec is listed below, but the full GRX-815/810 Di2 set-up is top notch- we even added the Bluetooth transmitter, complemented by Black Inc's Carbon Integrated Bar-Stem; and the bike is carried by 3T's Discus 45|32 carbon wheelset on 700x38 Panaracer Gravel King SK tubeless tires.