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.

Cyclescheme can save you up to 39% on a bike and accessories. Visit our Cycle to Work Scheme page to learn more and claim.
Product Highlights

The BallisTec carbon frame is light, stiff and compliant for a lively but composed ride.

The lightweight Kingpin system at the rear of the frame gives up to 30mm of plush suspension.

A precise, gravel specific 11-speed gear setup with a wide range of ratios is ideal for any terrain.

Clearance for big volume tyres grants increased traction and comfort over rough terrain.
Cannondale Topstone Carbon 4 Gravel Bike 2021
For riders who enjoy nothing more than spending long days in the saddle, seeking out new routes unbound to the limits of tarmac, the Cannondale Topstone Carbon 4 Gravel Bike is a superb companion. The BallisTec carbon fibre frame and fork deliver a light handling bike that surges when you give it a push, while the Kingpin suspension system really boosts compliance and comfort.
Ensuring you make the most of your riding off-road, Cannondale has specified the excellent Shimano GRX 800 groupset, with some key features that make riding the rough stuff a pleasure. The rear derailleur boasts a clutch mechanism which dramatically reduces chain slap, so you can ride harder over bumps. Shifting is quick and light, and the hydraulic disc brakes provide all the stopping power you need, in wet or dry conditions.
Cannondale's much-admired OPI SpideRing crankset comes with sub-compact chainrings and is paired with a wide 11-34t cassette so you can head off without fear of steep hills, and you'll have enough gears to keep up with friends on road bikes too. The wide WTB 37mm tyres come tubeless-ready along with the rims, so you can choose to set them up without tubes for even lower pressure and better traction on the trails.
Highlights
- Lightweight and strong BallisTec carbon fibre frame
- Kingpin rear suspension system
- BallisTec Carbon fork provides vibration-reducing lightweight steering
- Gravel specific Shimano GRX groupset
- Powerful Shimano hydraulic disc brakes
- Removeable mudguard bridge
- Large volume 37c clincher tyres from WTB offer offroad stability
- Wide-ranging gear ratio is perfect for any terrain
Technical Specification
Frame | Cannondale BallisTec Carbon Frame, Kingpin suspension system, 12x142 Speed Release thru-axle, dropper post compatible, direct line cable routing |
Fork | Cannondale BallisTec Full Carbon, 1-1/8" to 1.5" steerer, 55mm OutFront offset, flat mount disc, internal routing, 12x100 Speed Release thru-axle |
Headset | Integrated, 1-1/8" - 1.5" |
Bottom Bracket | Cannondale BB30 |
Stem | Cannondale 2, 6061 Alloy, 31.8, 7° |
Handlebar | Cannondale 3, butted 6061 alloy, 16 deg flare drop |
Bar Tape | Cannondale Bar Tape, 3.5mm |
Front Brake | Shimano GRX 800 hydraulic disc, 160mm RT70 rotor |
Rear Brake | Shimano GRX 800 hydraulic disc, 160mm RT70 rotor |
Brake Levers | Shimano GRX 800 hydraulic disc |
Front Derailleur | Shimano GRX 800, braze-on |
Rear Derailleur | Shimano GRX 810, Shadow RD+ |
Shift Levers | Shimano GRX 800, 11-speed |
Chain | Shimano HG601, 11-speed |
Cassette | Shimano 105, 11-34, 11-speed |
Crankset | Cannondale, BB30a, OPI SpideRing, 46/30t |
Front Wheel | WTB KOM Light i23 TCS, 28-hole, tubeless-ready rim | Formula cartridge bearing, Center Lock, 12x100mm hub | stainless steel, 14-gram spokes |
Rear Wheel | WTB KOM Light i23 TCS, 28-hole, tubeless-ready rim | Formula cartridge bearing, Center Lock, 12x142mm hub | stainless steel, 14-gram spokes |
Front Tyre | WTB Riddler TCS Light, 700 x 37c, tubeless-ready clincher |
Rear Tyre | WTB Riddler TCS Light, 700 x 37c, tubeless-ready clincher |
Saddle | Fabric Scoop Shallow Elite, cro-mo rails |
Seatpost | Cannondale 2, UD Carbon, 27.2 x 350mm |
Pedals | Available to be purchased separately |
Accessories | Cannondale Wheel Sensor, Removable mudguard bridge |
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 Topstone Carbon 4 Gravel Bike 2021 Sizing
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