The new definition of the modern performance road bike

Learn More     Buy Now

What is it?

The Sika is a cutting-edge road bike that delivers top-level
performance in a package tailored for real riders, not for pros. It combines feathery
lightness, high stiffness and sleek aero with a less extreme position, confident
handling, and clearance for 40mm tyres. It’s the ride of your life, all day long.

Who is it for?

Road riders who want to ride all day in comfort on a mix of roads
while enjoying top-tier performance, but have grown tired of the limitations and
fussiness of bikes designed purely for racing. Common sense was a key ingredient.

Why did we make it?

Because we could see something missing from modern
road bikes and felt that we could deliver it by drawing on our vast experience of
building custom bikes. We understand that many riders want a superlight, fast,
confident bike that can take bigger tyres and has a real-world stack height.

Key Features

690g frame weight, size M

Float up the mountains on one of the lightest bikes in its class. A sub-7kg build is easily achievable.

40mm tyre clearance

Conquer bad roads, cobbles and even gravel with the option to run tyres up to 40mm in width. Road bike tyres have been getting bigger at a rapid rate in recent years. While 30 and 32 are the new norm, riders who live in areas with worse roads already want even wider tyres. The Sika is ready for anything, including the future.

Real world rider fit

We built a bike for normal people who want to ride all day, not pros wanting an extreme position. Drawing on our experience of building hundreds of custom bikes, and on our relationships with the world’s best bike fitters, we shaped the Sika to be comfortable for the vast majority of riders, without requiring an unsightly stack of spacers or ruining the bike’s elegant proportions.

Sika one-piece cockpit

Ergonomics and aerodynamics harmonise in our first cockpit, designed entirely in- house. The top section is shaped with proven NACA profiles to deliver a significant aero gain in this critical area that meets the cleanest airflow. The tops also sweep back at a 3-degree angle for a natural hand position. Brake hose routing is fully internal.

T47 bottom bracket and Universal Derailleur Hanger

Secure, quiet and serviceable for life, the T47 standard, invented by Chris King, uses a threaded metal shell. It’s loved by mechanics and by riders weary of creaking pressfit BBs. The SRAM UDH is the easiest to source and replace should you need to, wherever you are. These are common sense choices.

27.2mm round seatpost with traditional external clamp

The most comfortable and practical solution. A round 27.2mm seatpost is able to flex more than any aero-shaped post, adding comfort at the saddle where it matters most. We decided this was more important than a small aero gain. The round post also gives you the freedom to choose any post, rather than being stuck with a proprietary design. We chose a traditional clamp because they’re so much easier to live with, especially if you travel with your bike, compared to a hidden wedge that usually binds in place.

Lightness

The Sika frame weighs 690g in size M, placing it among the very lightest in the world for a bike with 40mm tyre clearance and aero optimisation. A sub-7kg build, with pedals, is easily achievable with no extreme components.

What’s more, lightness was never the sole focus. This figure was achieved while also hitting our high targets for lateral and torsional stiffness, and with aero-optimised tube shapes. The key to this lies in the high grades of carbon fibre we selected.Read more on that below.

Handling

One word sums up the Sika’s handling – confidence. It’s precise, stable and planted, whether on a fast Alpine descent or broken back roads. We gave the Sika the same dynamic and assertive handling that is a hallmark of our custom bikes, with short trail and longer chainstays.

Through our custom bike programme, we design more frame geometries each year – over 100 – than even the biggest brands do in a decade. What’s more, our bikes are tailored to our customers, not dictated by the demands of pros. We know what real riders want and we know how to deliver it.

Ride quality

The Sika is a bike to ride all day on all roads. The rear triangle is closely derived from our custom bikes, where it’s well proven to ride with velvet smoothness. Add to that, a 27.2mm diameter seatpost that’s able to deflect over bumps, a compliant fork, and capacity for tyres up to 40mm and the result is a bike that floats over bad roads.

This smoothness is achieved without sacrificing performance thanks to the very high grades of carbon fibre used and tireless development to get the best from them. The frame shapes play a key role, too. The aggressively truncated profile of the downtube delivers the lightness, comfort and stiffness of a round tube, with the aero
benefits of an airfoil. The bottom bracket shell is maximised upwards and in width to boost stiffness in this key area.

Aero

While the Sika is not an outright aero bike for racing, it is aero-optimised to reduce drag without compromising ride quality or lightness. The tube shapes are derived from proven NACA profiles with truncated airfoils – like a tapered D-shape – which are very effective at reducing drag while preserving lightness and ride quality.

Why include aero if the bike isn’t for racing? On the flat, around 80% of your effort is fighting air resistance and if your bike is more efficient, then you save energy to spend going further, higher or faster. Additionally, with nearly all bikes now aero- optimised to some extent, we didn’t want to leave performance on the table and put you at a disadvantage on a group ride.

National Advisory Committee for Aeronautics, the godfathers of aero and the predecessor to NASA.

Carbon lay-up explained

Ride quality is an obsession at FiftyOne Bikes. We knew how we wanted the Sika to
feel and our experience and expertise both in building close to 500 custom frames
and developing the Assassin gravel bike gave us the tools to achieve it. The Sika is
made with an especially high-grade mix of Toray carbon fibres – the exact blend of
fibres is our secret for now – with each one used according to its particular qualities.
This is how the Sika is so light, stiff and comfortable. There’s no magic, only
obsessive engineering and a readiness to invest in the best materials.

Lifetime warranty and UCI approval

Ride in total peace of mind. The Sika received UCI approval and carries a lifetime
warranty.

Geo Bar/Stem Chart