Factor unveils five-spoke 'rest day' wheels which remind us of banned tech from a bygone age

New wheels look to be based on the Aerospoke design of the 1980s - even though monocoque wheels were banned in 2001

Factor five-spoke wheels
(Image credit: Rob Gitelis)

One of Israel Start-Up Nation’s Factor Ostro bikes has been photographed at the Tour de France with a brand new set of five-spoke wheels that appear to be based on the Aerospoke design of the 1980s.

Factor owner Rob Gitelis posted a photo on Instagram a photo of one of the team’s race bikes fitted with a set of the wheels, which look to be carbon monocoques.

The Aerospoke wheel was developed in the USA for triathlon in the late 1980s and by the 1990s there were similar designs that were being used in pro road races, most notably the Spinergy Rev-X, which was famously ridden by Mario Cipollini.

Mario Cipollini

(Image credit: Graham Watson)

However, the Spinergy Rev-X and other non-spoked wheels of its type were banned in 2001 after it was blamed for some nasty injuries and catastrophic failures: Michele Bartoli’s kneecap was reportedly severed by one during the 1999 Tour of Germany, Paolo Bettini nearly cut his hand off on one, and there was a steady stream of reports of Spinergy Rev-X wheels ‘exploding’ underneath riders without warning, causing broken bones and other gruesome injuries.

The latest 2021 clarifications to the UCI wheel regulations state: “For massed start competitions in the disciplines road and cyclo-cross, only wheel designs granted prior approval by the UCI may be used. Wheels shall have at least 12 spokes; spokes can be round, flattened or oval, as far as no dimension of their sections exceeds 10mm.”

The new wheels - branded Black Inc, which is Factor's wheel division - clearly are seven spokes short of the required 12 and in their dimensions are closer to 10cm than 10mm in width.

So why would Factor revive the design? The five airfoil-shaped carbon spokes are more aerodynamic than standard spokes, but the descendants of these wheels were much more aerodynamic than the original Aerospokes: the HED tri-spoke and the Mavic IO (also a five spoke) won countless Grand Tour time trials, world championships and Olympic medals between them and by then the Aerospoke had mostly disappeared from competitive cycling.

Black Inc's Tom Fleetwood told Cycling Weekly: "These were just ridden by the team on the rest day only and aren't UCI legal."

The Factor wheels are not quite identical to the Aerospokes: they feature a straight edge and then a faired section where the spokes meet the rim, whereas the Aerospokes' spokes flared symmetrically at the rim. This suggests they have been developed for a specific purpose.

But if not for road racing, then what? The original Aerospokes became popular with bike messengers in the 1990s and 2000s: the Aerospoke front and spoked rear (fixed of course) almost became the courier's uniform. Could these new Black Inc wheels be aimed at urban riding?

Fleetwood promised he would send us more info on the wheels in due course.

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Simon Smythe

Simon Smythe is a hugely experienced cycling tech writer, who has been writing for Cycling Weekly since 2003. Until recently he was our senior tech writer. In his cycling career Simon has mostly focused on time trialling with a national medal, a few open wins and his club's 30-mile record in his palmares. These days he spends most of his time testing road bikes, or on a tandem doing the school run with his younger son.