The Fulcrum Red Wind H50 XLR Cult wheels cost £250 more than the USB Red Winds that we've reviewed previously and that's all for something you can't even see – the bearings.
The CULT (Ceramic Ultimate Level Technology) bearings are rounder, harder and more durable than steel bearings, but in order to counter their hardness, an equally hardwearing bearing race made of Cronitect steel is needed, whose corrosion resistance negates the need for lubricating grease, requiring only a small amount of oil.
The tolerances and lack of grease reduce hub friction, which Fulcrum tests by spinning a wheel to 500rpm then allowing it to decelerate. Standard bearings spin for around eight minutes, USB bearings for 15, and CULT bearings around 45 minutes!
On the road those claims are hard to quantify, but the Red Wind XLRs do feel very smooth. Of course, more crucial to acceleration is rotational weight, and with an undrilled aluminium rim bed bonded to the structural carbon element, these aren't incredibly light, but without skewers weigh a respectable 1,700g (760g front/940g rear).
The Fulcrum's 21mm width and aero profile rims are very conventional. The rear wheel's larger drive-side flange and 2:1 spoking keeps things taut and efficient. Lateral stiffness is very good, aiding sprint efforts, fast cornering and sharp acceleration at all speeds, while that aluminium braking track offers consistent braking.
But though the Red Winds are certainly quick, there are times when they are less stable than the wider profile aero rims that are rapidly gaining in popularity.
Overall these are a well-made, competent set of medium depth hybrid wheels with superior bearings and decent, if dated, aero performance, but still capable of mixing it on all terrain.