Fulcrum introduces “deeper, wider and more aero” Speed 42 and 57 wheels

Campagnolo’s Fulcrum brand has introduced new Speed 42 and 57 wheels that, it says, “offer the best performance in terms of aerodynamics, rolling resistance, lightness and handling, without compromising safety”.

As well as having deeper rim profiles than the previous Fulcrum Speed 40 and 55 wheels, the new models are said to be wider and lighter with improved aerodynamics. The hubs and spokes are new too. Fulcrum claims a 1,410g weight for the Speed 42 (compared with a claimed 1,470g for the existing Speed 40) and 1,495g for the Speed 57 (compared with a claimed 1,580g for the current Speed 55).

New rims

With rim depths of 42mm and 57mm, the new Fulcrum wheels are 2mm deeper than previously while the inner rim width has been increased from 19mm to 23mm. The nose of the rim – where the spokes enter – has also been widened. It now has a radius of 9.5mm.

“The new wider rims, paired with 28mm tyres, provide a level of performance without compromises, with optimum aerodynamic penetration, rolling resistance and comfort,” says Fulcrum. “The average aerodynamic advantage, measured in the wind tunnel with wind blowing from the front, has been increased by 10% compared to a rim with an inner rim width of 19mm.”

Fulcrum doesn’t offer information on the performance at other yaw angles.

“Despite the higher profile, handling has been improved considerably,” Fulcrum says. " [We] carried out a specific research project to define a formula that would take into account the energy dissipated by the wheel during changes in direction and the flexural deformation based on roll and inclination. The data measured confirmed that the new Speed wheels have seen an improvement of up to 17% compared to the previous generation.”

Find out more about Fulcrum’s criteria for measuring handling down below.

Fulcrum says that it uses a new composite mix of FF100 high modulus unidirectional fibres for the Speed 42 and 57.

“Through numerous experiments we have reached the perfect mix of fibres, which along with their correct layup and an extremely precise control of the resin, allows us to create a product that works in the correct elasticity field, guaranteeing hors catégory performance specifications and a superior ride feel,” it says.

As previously, the inner rim channel uses Fulcrum’s MoMag tech which means it contains no holes. This allows the use of standard clinchers or tubeless tyres without the need for tubeless rim tape.

Fulcrum says that the lack of holes allows it to maintain uniform stiffness around the rim and greater resistance to impacts.

Fulcrum uses other existing technology including an undrilled rim bed – the spoke holes are moulded in – and its DRSC (Directional Rim-Spoke Coupling) system where a plastic support is sunk in the carbon between the nipples and the rim to provide increased stiffness and durability.

The hubs

Fulcrum says that the hubs have been completely redesigned “to house a more precise and lighter freewheel mechanism than the previous version”.

“The size of the flanges has been reduced by 40% and the central body by 10% compared to the previous generation, giving the wheel greater resistance with lower aerodynamic drag, without compromising torsional stiffness,” says Fulcrum.

As in the previous models, the bearings in the Speed 42 and 57 are cup and cone and use Fulcrum’s USB (Ceramic Ultra Smooth Bearings) system. 

The freehub now features a 36-tooth ratchet system. It is available with Campagnolo N3W, Shimano HG and Sram XDR bodies.

The spokes

The spokes have been specifically designed for the Speed wheels. They’re laced using Fulcrum’s Two-to-One system “which doubles the spokes in the areas subject to greater mechanical stresses to prevent the dispersion of energy and contrast the torsional force”.

The front wheel has 16 spokes on the disc side and eight on the non-disc side. The rear wheel is built the opposite way, the idea being that the higher number of spokes on the drive side can handle the forces of the transmission.

“This specific construction, along with the perfect tensioning of the spokes, provides the wheels with the torsional stiffness required to ensure the maximum transfer of power,” says Fulcrum.

“Considering the flexural deformation and the torsional deformation based on the translation, rolling and inclination energies, the new Speed achieve a 10% improvement compared to the previous generation.”

Handling

As mentioned above, Fulcrum has developed “specific, objective and quantitative parameters” for judging the handling and reactivity of its wheels.

“The physical quantities used to define these indexes are mass (kg), rotational inertia (kg/m2), flexural stiffness (N/mm) and torsional stiffness (Nm/rad), whilst the joule (J) is used to measure the energy dissipated,” Fulcrum says.

“Handling considers the energy dissipated by the wheel during a change in direction. The less energy is dissipated the higher the performance index. The handling assessment considers the flexural deformation based on rolling and inclination.   

“Reactivity considers the energy dissipated by the wheel during a sprint, therefore the flexural deformation and torsional deformation based on the translation, rolling and inclination energies. In other words, the rider’s pedal stroke deforms the wheel and the energy absorbed for the deformation is not transferred to the ground to move forward. The greater the amount of energy absorbed the lower the reactivity and therefore the performance of the wheel.”

Fulcrum says that its aim isn’t to identify the wheels with the highest level of performance in these terms but to understand how different designs are better suited to specific uses and for different riders.

“For example, a wheel can’t be very reactive and very comfortable at the same time,” it says. “A higher flexural stiffness results in greater reactivity, whilst low stiffness is synonymous with comfort. It’s therefore not necessarily true to say that a very stiff wheel is the best wheel: the aim is to find the right balance to offer a wheel package suited to the requirements of every single rider.”

The Fulcrum Speed 42 wheelset is available now priced at £1,999.99. The Fulcrum Speed 57 wheelset and a Fulcrum Speed 42/57 combo will be available from June 2023 at the same price. 

Our man Aaron Borrill has a pair in for review so we'll let you know how they perform soon.

www.fulcrumwheels.com