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New Fulcrum Speed 25 climbing wheels weigh just 1,285g

Will Strickson
15 Jun 2022

Fulcrum has used some ingenious features to keep the disc-brake only Speed 25 wheelset light but stiff

Fulcrum has launched the Speed 25 wheelset, a lightweight climbing design with an asymmetrical rear rim and a tubeless setup that doesn’t require rim tape.

The wheels weigh a claimed 1,285g and have a 21mm internal rim width for use with modern tyre sizes. They also use a new, svelte hubset design as well as Fulcrum’s USB hybrid ceramic bearings.

Using its iconic Racing Light XLR wheels as inspiration, the Speed 25 wheels are the Italian brand’s new disc brake-only race wheels for when uphill speed – or better stability in the wind – is desired.

Fulcrum says smoothness, handling and aerodynamics have also been a focus in their development. The brand has used an asymmetrical rear rim, which it says brings significant stiffness improvements.

They’ve also been equipped with Fulcrum’s 2-way fit system that allows for tubeless tyres to be fitted without rim tape.

The new wheels sit above Fulcrum’s previous top-tier design, the Racing Zero Carbon DB wheels, and retail for £1,999.99.

Minimalist details

Fulcrum cites three key features that help bring the Speed 25s in at that claimed weight. The first, and most obvious, is that they have a low 26mm rim depth front and rear.

Secondly the carbon rims use a technology that the brand dubs DIMF. That stands for ‘direct in-mould finish’, meaning there’s no paint or finishing – that would potentially add weight – required once the rims have been fabricated.

Finally, Fulcrum says hub weight has been reduced too, while also being aerodynamically refined.

The combination of those manufacturing techniques has resulted in a claimed wheelset weight of 1,285g. That saves a significant 165g over the 1,450g Racing Zero Carbon DB wheels.

Rounded performance

The other aspect that Fulcrum has emphasised is the Speed 25’s ride feel, saying the climbing benefits of the wheelset’s low weight would be worthless without accomplished performance in other riding situations.

According to the brand one of the biggest parts of that comes from the asymmetrical rear rim. While the symmetrical front rim promotes aerodynamic efficiency, Fulcrum says the skewed rear dish angle works to boost lateral stiffness.

Then there are the spokes, which are double butted, straight pull aero spokes that don’t touch at the point they cross each other. Fulcrum says this adds durability as well as further stiffness.

USB hybrid ceramic bearings have also been included in the hubs, which Fulcrum says produce 50% less rolling resistance than standard bearings. The hubs’ axles are made from a single CNC’d aluminium piece, which the brand says provides a stiff and solid base for the wheelset’s connection to the rest of the bike.

Finally, the Speed 25s have been designed with Fulcrum’s clever 2-Way Fit system. The wheels use a technology called ‘Mo-Mag’, whereby the spoke nipples are inserted into the rim void via the valve hole, then guided into the nipple beds with magnets.

This means the rim channel doesn’t have to be drilled to get nipples seated, meaning the wheels are naturally tubeless ready and don’t require the application of rim tape in order to create a tubeless seal.



Spec

  • Rim width: 27.6mm
  • Inner rim width: 21mm
  • Rim depth: 26mm
  • Freehub compatibility: XDR, HG11, N3W
  • Weight limit: 120kg
  • Weight: 1,285g
  • Price: £1,999.99

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