If your life revolves around the quest for podiums; if you weigh, measure and analyze every element of your preparation, if your idea of fun is turning yourself inside out till your eyes bleed and your competitors drop; basically, if you’re obsessed with XC, the allnew

F-Si is the bike for you. Built to climb faster, descend harder, and sprint better than any other hardtail out there, it’s serious XC goodness for those with serious XC issues.

The fastest, best climbing, best descending XC hardtail on the market.

Rider Profile - World Cup XC racers or anyone who aspires to XC racing glory

Wheel/Tyre Size - 27.5/29 x 2.25

Travel - 100mm (F)

Rider Position - Pure Modern XC. Low, flat back with centered weight distribution.


BallisTec Carbon Construction - Refined design and new layup shaves 70 grams off the Hi-MOD frame.

Tapered Headtube - The new Lefty Ocho features a standard 1 1/2” to 1-1/8” tapered steerer, so instead of the HeadShok standard headtube of the previous model, the new F-Si uses a tapered headtube, for better compatibility and lighter weight.

Integrated Seat Binder - A wedge-style seat binder in the seat tube eliminates the collar for a cleaner look and allows more seatpost flex for more comfort.

Interchangeable Routing Chips - Easy-to-use internal cable routing chips allow you to customize your cable routing to your preference.

Speed Release Thru-Axle - A faster, more convenient thru-axle. The axle stays in the hub for faster wheel changes. Compatible with any 148x12mm hub.


Light is Right One of the lightest XC hardtails in the world, the new F-Si is over 300 grams (almost 3/4 lb) lighter than the previous version. Frame shaves 70 grams and the new Lefty Ocho chops a whopping 250 grams.

Even More Outfront - Slacker head angle than previous F-Si (about a degree on most sizes) adds even more stability and control on sketchy descents. Custom long fork rake on the Lefty Ocho (50mm on XS, 55mm S-XL) keeps handling precise and agile at slower speeds.

AI AdvantageAI offset drivetrain delivers even shorter chainstays (427mm) than the original, for climb-winning traction and agility, with clearance for big tires, 2x chainring compatibility and a stiffer, stronger rear wheel.

Longer and Lower - Reach to the head tube is increased slightly for improved control. An integrated seat binder looks super clean and exposes more seatpost length for improved comfort.

Even Smoother - New race-tuned stiffness keeps things stout where needed for power transfer, but adds even more bump-eating comfort so you can go harder longer


Frame: All-new F-SI, Ballistec Carbon, Save, PF30A, Tapered Head Tube, Speed Release 12mm Thru Axle, Ai Offset

Fork: All-new Lefty Ocho, 27.5/29”, 100mm, Chamber Damper With Cable Lockout, Oppo Spring System, Tapered Steerer, 50/55mm Offset

Rims: Hollowgram 23, Superlight Hi-impact Carbon, Tubeless Ready, 28h, 23mm Inner Width

Hubs: Lefty 60 Front, Hollowgram 12x148 Rear W/ DT Swiss Internals

Spokes: Hollowgram, Double-butted Straight Pull (Ai Offset Dish - Rear)

Tyres: Schwalbe Racing Ray 27.5/29 X 2.25” Front, Racing Ralph 2.25” Rear, Snake Skin, Addix Speedgrip Compound, Tubeless Ready

Pedals: Not Included

Crank: Truvativ Stylo Carbon, 34T, AI Custom

Bottom Bracket: Cannondale Alloy Pressfit30

Chain: Sram GX Eagle, 12-speed

Rear Cogs: Sram XG-1275, GX Eagle, 10-50, 12-speed

Rear Derailleur: Sram X01 Eagle

Shifters: Sram X01 Eagle, 12-speed

Handlebar: Cannondale C1 Flat, Carbon, 8° Sweep, 760mm

Grips: Cannondale Locking Grips

Stem: Cannondale C1, 7075 Alloy, 1-1/8”, 31.8, 7°

Headset: Integrated, 1-1/8 To 1.5”, Sealed Angular Contact Bearings (Integrated Steer Stop Size Small And Extra Small Only)

Brakes: Shimano Deore Xt Hydro Disc, 160/160mm XT Rotors

Brake Levers: Shimano Deore Xt Hydro Disc

Saddle: Fabric Scoop Flat Race, Ti Rails

Seatpost: Cannondale C1 Full Carbon, 27.2 X 350/400mm

Sizes: XS, S, M, L, XL

Colour 1: Black Pearl W/ Acid Red, Tangerine And Volt - Gloss (BPL)

Extras: Speed Release Rear Axle


Please note that this information is provided only as a guide; for the best sizing information we always recommend visiting your local Bikebug store.

Be The First To Review This Product!

Help other Bikebug Pty Ltd users shop smarter by writing reviews for products you have purchased.

Write a product review

Others Also Bought

More From This Category