Why buy your bike from Sigma Sports?
Don't hesitate to reach out to us. It's our goal to answer all of your questions and offer the best advice from our experts. We’ll be happy to answer any questions you may have. Contact us now or visit us in-store.
All our bikes are fully built by our Cytech qualified mechanics. To find out more, see the Built, Checked, Tuned and Tested section below to see how we'll deliver your bike.
We offer FREE DELIVERY of your bike to your home or place of work. Once you've placed your order, our Customer Care team will be in contact to offer a convenient delivery date of your choice.
We've partnered with PedalSure to offer you 30-DAYS FREE bike insurance on new bikes over £400. Visit our Cycle Insurance page to learn more and claim.
Cannondale F-Si Carbon 4 Mountain Bike 2021
The Cannondale F-Si Carbon 4 Mountain Bike is a lightweight lefty steed with a 900 gram frame: race-ready and performance-focused. Real compliance meets durability in the BallisTec Carbon frame, complete with OutFront steering geometry for nimble handling and traction, enabling it to hold its own on tough terrain. The Lefty Ocho fork aids in keeping weight down and features 100mm of travel to iron out lumpy runs with ease, whilst the remote lockout eliminates any bobbing - without even having to lift hands from the bars.
SRAM NX Eagle 1x12-speed components deliver responsive shifting and a generous gearing range suitable for undulating gradients and fast-rolling 29" wheels roll comfortably over rocks or roots in their path. Should speed need to be taken down rapidly, the Shimano MT500 hydraulic disc brakes get the job done regardless of conditions.
Highlights
- Asymmetric Integration drivetrain for podium-level traction and clearance
- Proprietary BallisTec carbon is custom-tuned for rigidity, compliance and weight-saving
- Shimano MT500 hydraulic disc brakes
- Cannondale Lefty Ocho fork, 100mm travel
- Tapered head tube
- Clean, configurable internal cable routing
- Speed Release rear axle
- The integrated wheel sensor delivers hyper-accurate speed, route and distance info, registers your bike, reminds you of needed servicing and more, all through the free Cannondale App
Technical Specification
| Frame | Cannondale BallisTec Carbon, SAVE, PF30-83, tapered head tube, Speed Release 12mm thru-axle, Ai Offset |
| Fork | Cannondale Lefty Ocho, 100mm, Chamber Damper with remote lockout, OppO Spring System, tapered steerer, 55mm offset |
| Headset | Cannondale Integrated, 1-1/8 to 1.5”, sealed angular contact bearings (Integrated steer stop size small and extra small only |
| Bottom Bracket | SRAM DUB PF30 MTB83 |
| Stem | Cannondale 3, 6061 Alloy, 31.8, 7° |
| Handlebar | Cannondale 2 Flat, butted 2014 Alloy, 31.8mm, 3° rise, 8° sweep, 760mm |
| Grips | Fabric FunGuy |
| Front Brake | Shimano MT500 hydraulic disc, 160mm RT54 rotors |
| Rear Brake | Shimano MT500 hydraulic disc, 160mm RT54 rotors |
| Brake Levers | Shimano MT500 hydraulic disc |
| Rear Derailleur | SRAM NX Eagle |
| Shift Levers | SRAM NX Eagle, 12-speed |
| Chain | SRAM SX Eagle, 12-speed |
| Cassette | SRAM SX Eagle, 11-50, 12-speed |
| Crankset | SRAM X1-1000 Eagle DUB, 34T, Ai Offset |
| Front Wheel | Cannondale Lefty 60 hub, WTB STX i23 TCS, 32h, tubeless-ready rim, DT Swiss Competition spokes |
| Rear Wheel | Shimano MT400 12x148mm thru-axle hub, WTB STX i23 TCS, 32h, tubeless-ready rim, DT Swiss Competition spokes |
| Front Tyre | Schwalbe Racing Ray Performance, 29 x 2.25”, Addix Compound, tubeless-ready clincher |
| Rear Tyre | Schwalbe Racing Ralph Performance, 29 x 2.25”, Addix Compound, tubeless-ready clincher |
| Saddle | Fabric Scoop Shallow Sport, steel rails |
| Seatpost | Cannondale C3, 6061 Alloy, 27.2 x 350mm (S), 400mm (M-XL) |
| Pedals | Available to be purchased separately |
| Accessories | Cannondale Wheel Sensor |
Built, Checked, Tuned and Tested
All our bikes are fully built, checked, tuned and tested by our Cytech qualified mechanics and then securely packaged, ready for delivery. All you have to do is add the pedals (if specified), attach the handlebars to the stem and tighten them following the included detailed instructions or by watching our video and using the provided FREE tools. Visit our Bike Assembly page to see how you assemble your new bike once you receive it.
All bikes collected from our shop, are built, tested and ready to ride.
Please note, occasionally, manufacturers may change the specification without notice. Bicycles do not come with pedals unless otherwise specified. We do not install accessories to bikes, including mudguards.
Cannondale F-Si Carbon 4 Mountain Bike 2021 Sizing
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