Fulcrum has released the Speed 25+, which claims to be the lightest low-profile disc wheels ever made.
The listed weight for the climbing wheelset is just 1,270 grams, some 15 grams lighter than the Speed 25 wheels. Of course, certain wheelsets with claimed weights lower than that may well spring to mind - we'll unpick what we believe Fulcrum's justification for this claim is further down.
Coming back to the hoops, the ‘plus’ of Fulcrum's Speed 25+ signifies that it is the Italian brand's range-topping offering - and here that means a new carbon construction, premium ceramic bearings and redesigned freewheel body.
(Image credit: Fulcrum)
As for the measurements, the Speed 25+ retains the 26mm rim depth and 21mm internal rim width used by the Speed 25. The tubeless ready wheels feature a hooked rim profile and an undrilled rim bed that removes the need for additional rim tape.
The rim uses Fulcrum’s proprietary FF100 mix of resins with a Direct In-mold Matte Finish. The new wheel graphics feature a laser etched finish. While the Speed 25 wheels use Ultra Smooth USB ceramic bearings in the hub, the 25+ uses the Italian brand’s Ceramic Ultimate Level Technology, or CULT for short. Ultilising a cup and cone system rather than sealed bearings, all of the surfaces benefit from a ceramic treatment, with increased smoothness the intended goal.
(Image credit: Fulcrum)
By redesigning the freehub body Fulcrum says its reduced both the weight and the friction at play, with USB ceramic bearings used inside the body. XDR, N3W and HG versions are available to cover the use of SRAM, Campagnolo and Shimano cassettes. Other details include 24 aero straight pull spokes both front and rear and thru-axle compatibility.
It would seem that Fulcrum is using ‘under 30mm’ as its low-profile distinction. While there are 'climbing' wheelsets with a lower claimed weight, such as Roval’s Alpinist CLX II which tip the scales 1,265g and Black Inc’s 28/33 which are lighter still at just 1,142g for a pair, both of these feature rim depths of greater than 30mm (only in he rear in the case of the Black Inc model).
Indeed, the trend for all-rounders, road bike wheels that blend low weight with improved aerodynamics, means that finding a carbon rim under 30mm these days is relatively rare.
