New Fulcrum Speed 25 wheels, ready for climbing

Road 15 jun. 2022 16:06 Migue A.

Fulcrum launches its new low-profile Speed 25 road wheels, which stop the scale at just 1,285 grams.

Fulcrum Speed 25, lightness and control at the lowest possible level

After a few years where the trend was to go for more and more aerodynamic wheels, even for mountain use, the increase in the average weight of the bikes that has brought with it the generalization of disc brakes has led wheel manufacturers to recover the concept of ultralight wheels oriented to a pure mountain use.

Lightweight wheels not only have an impact on the overall weight of the bike and the benefit we get when overcoming the toughest ramps. The lower mass also makes it much easier to accelerate the bike and makes it more agile on downhills by significantly reducing inertia when changing direction in corners.

Fulcrum has taken up this concept by evolving the famous but discontinued Racing Light XLR to create its new Racing Speed 25, incorporating hubs with anchorage for center lock discs and a rim suitable to accommodate the increasingly common tubeless tires without increasing weight.

The scale decrees that Fulcrum has succeeded, achieving an excellent weight of only 1,285 grams. 

Down to the smallest detail

The process to achieve an ultralight wheel begins with the production of the rim. In the manufacture of these Racing Speed 25, Fulcrum uses its DIMF technology, which stands for Direct In-Mold Matte Finish, which allows the rim to come out of the manufacturing process with the final appearance it will have, avoiding the need for paints or lacquers that increase the weight of the rim.

To achieve this, Fulcrum applies a special resin to the outer part of the fibers that make up the rims of these Racing Speed 25 wheels, which will serve as a protective layer.

Also lightweight are the new hubs, which feature a minimalist body and CNC-turned axle to minimize weight without compromising strength and stiffness. They are designed to accommodate 24 spokes on both the aerodynamically cut front and rear wheels.

The hubs would not be complete without bearings of the same level. Fulcrum equips the Racing Speed 25 with USB ceramic bearings that improve wheel spin by 50% compared to standard bearings.

It should be noted in the spoke arrangement that the spokes have no contact with each other at their intersections thanks to the straight-throw design in the hub housing. In addition, the rear rim has an asymmetrical profile that balances the camber angle between the two sides of the hub to achieve similar spoke tension on both flanks, resulting in greater structural stiffness, with all the advantages in terms of acceleration, power transfer and cornering support that this entails.

Continuing the tour of these Fulcrum Racing Speed 25, note that it opts for a rim height of only 26 mm, maintaining a rounded profile to favor aerodynamics as much as possible with so little rim. The external width is 27.6 mm while the groove that houses the tire has a 21 mm sidewall spacing.

Fulcrum has applied its 2WayFit technology that defines the section of the rim to accommodate tubeless tires and, thanks to an interior without spoke nipple holes, achieves greater sealing without having to use any type of rim tape.

To avoid having to drill holes, Fulcrum inserts the spoke nipples through the valve hole and guides them into place using a magnet.

These new Fulcrum Racing Speed 25 are already available at the brand's points of sale with the option of having HG hub for Shimano, XDR for SRAM or N3W for Campagnolo cassettes for a price that varies only a few euros between versions and that starts at the 2,186 € that we will have to pay for the pair of wheels with HG hub.


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