I say that Fulcrum is teasing us, because ’tis the season for 25mm wide carbon tubulars for disc brakes. Cyclocross is upon us once again, and a light & fast carbon tubular wheelset is still the unmatched way to claw your way to the top of a cross podium. Even if these are being called a “no-compromise disc brake race-day wheelset” targeted at roadies, for sure I would first envision gluing some 33mm tubulars up and getting them dirty. Alas, they won’t make it in time for this cross season, so I guess they’ll have to wait to race on the road next spring.
Speed 55T DB, aero road disc brake tubular race wheels
Following on top of the 40 & 50mm deep Speed rim brake carbon clinchers (not officially tubeless compatible) and the 2-WayFit tubeless Racing 4-7 DB disc brake clinchers that Fulcrum rolled out a month ago, the new Speed 55T DB race wheels deliver a proper aero carbon tubular option for disc brake road racing.
The new wheels share a lot of the same tech we saw in the new Speed & Racing clinchers as well as the Campagnolo Bora One DB carbon tubulars introduced at the start of the summer. The new Speed 55T DB wheels use the same 2:1 spoke lacing that Campy used to favor the disc side up front & driveside in the back on the new Boras, and a less dramatic application of their grouped G3 lacing. That helps even spoke tension, while building wheels that stay true longer.
The new wheels use an all-new, lighter 55mm deep aero rim profile with a more snubbed nose, at most 26.5mm wide & 25mm wide at the tubular bed, all without a braking track thanks to discs. Without having to reinforce a brake track, or deal with brake heating or even tire pressure, Fulcrum says the new ‘longitudinal twill’ carbon construction yields a rim that maintains strength and lateral rigidity, while also is more elastic for a ride significantly less harsh than conventional deep section carbon wheels. That wider rim bed, uninterrupted by spoke holes, makes the wheel aerodynamically optimized for a 25mm tubular road tire, but also offers good support for wider tires.
Like the disc brake Boras, the new Fulcrum Speeds use a three-piece front hub with a carbon center section, while the rear hub is one piece alloy to better distribute the toque delivered to both sides of the rear wheel from acceleration & deceleration. Fulcrum pairs the wide, oversized flange hubs with 21 straight pull, double butted, bladed spokes both front & rear.
Unlike the Boras, the Speed 55T DB wheels are available with two different hubsets – for either 6-bolt or centerlock/AWS rotor compatibility. The also come standard with Shimano cassette bodies, but can be adapted to either Campagnolo freehubs or a SRAM XD driver. Bearings are premium CULT ceramic in a cup & cone setup to make them easy to service & dial in the perfect preload. Even in a sea of road disc brake options, the hubs look like they stick with now industry standard 12×100 & 12x142mm thru-axle spacing, dropping the need for endcaps or other axles options.
Incorporating pretty much all of the highest tech from Fulcrum for road disc brake wheels, the Speed 55T DB claims a total weight of just 1395g, which sounds great factoring in disc brakes and a 55mm deep aero profile. We haven’t seen pricing yet (expect ~2000€), but it is helpful to remember that Campy tends to make their carbon tubulars a bit cheaper than their clincher counterparts thanks to simpler rim construction. And we have time to wait. The new wheels aren’t slated for availability until March 2018.
