Fulcrum has released new Speed 42 and 57 wheels, with deeper and wider rims than the previous iterations of Speed.
The new disc-brake only wheels replace the previous 40mm and 55mm sizes, with the 42mm wheelset weighing 1,410g, while the 57mm version is said to weigh 1,495g.
The inner rim width has also been increased from 19mm to 23 mm, and the nose of the rim has been widened with a radius of 9.5mm
Fulcrum says 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 19 mm.
Despite the higher profile, handling has been improved. Fulcrum 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.
According to Fulcrum, the data measured confirmed the Speed has seen an improvement of up to 17% compared to the previous generation.
The inner rim channel does not have any holes thanks to MOMAG assembly technology, which allows for a 2-WAY FIT tubeless rim without the need for tubeless rim tape.
The presence of the traditional hook ensures compatibility with all tube-type and tubeless tires.
The lack of holes in the rim channel allows Fulcrum to maintain the same stiffness along the whole perimeter and achieve greater resistance to impacts. This is also helped by the nipple holes, which are created in the mould, without having to drill the rim like traditional wheels.
The rim is constructed with resins and fibres made to Fulcrum specifications where, unlike previous versions, it uses a new composite mix of FF100 high modulus unidirectional fibres.
Fulcrum also utilises its patented DRSC™ (Directional Rim-Spoke Coupling) system. A specific plastic support is sunk in the carbon, between the nipples and the rim, to provide greater stiffness and durability of the system, distributing the stress of the nipple on a wider area more uniformly and avoiding potential situations of galvanic corrosion.
The internal finish of the channel is obtained with C-LUX™ technology, which is polished to ensure an easy and optimal mounting and seating of the tire, while the external rim finish is obtained with the DIMF (Direct Inmold Matt Finish) technology, which has a matt finish.
For the Speed 42 and 57, Fulcrum has used 24 aerodynamic flat spokes 2/1,6/2 mm and 2/1,7/2 mm, designed specifically for this wheel and laced with the Two-to-One™ system, which doubles the spokes in the areas subject to greater mechanical stresses.
The front wheel has 16 spokes on the disc side and 8 on the other side, whilst the rear wheel is built in the opposite way to contrast the forces developed by the transmission.
The hubs have been 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.
The bearings in the Speed 42 and 57 are cup and cone and utilise the USB™ system (Ceramic Ultra Smooth Bearings).
The hub system benefits from an aircraft grade aluminium axle, which allows it to work with centesimal tolerances.
The ratchet system of the freewheel has been reinforced and increased in size so it now houses 36 teeth. The wheel is available with Campagnolo N3W, Shimano HG and SRAM XDR freewheel bodies.
Read more: Apidura publishes its first Impact Report
The Speed 42 and 57 are the culmination of a process that included more than 4000 hours of testing in the wind tunnel, laboratory and the open road.
The brand said: “We tested seven versions of the rim, in multiple configurations, in order to obtain the best performance in terms of aerodynamics, rolling resistance, lightness and handling, without compromising safety.”
The graphics have been redesigned too and reflect the new brand identity, with a refined design, which includes new icons that provide all the product’s technical information.
Speed 42 (available now) – £1,999.99 RRP
Speed 57 (available June 2023) – £1,999.99 RRP