Consumer NOVEMBER technology
2019
Easy
folder
Once considered the preserve of eccentric enthusiasts,
Crosshead, a UK built folding bicycle marries compact commuter
convenience to road bike performance. Jon Excell took it for a spin.
folding bikes have become hugely popular - even
fashionable - in recent years.
And in the wake of the Covid-19 crisis, as
commuters switch in greater numbers to more
socially distanced modes of travel than bus and
tube, it’s probably safe to assume that this form of
transport will only become more popular. Indeed, market
researcher Grand View Research predicts that the global
market for folding bikes will grow by 9 percent in the next five
years
The current market is dominated by UK firm Brompton,
which sold almost 50,000 bikes in the year to March 2019 and
has held on to its share in the face of numerous competitive
efforts to develop a lower-cost alternative.
But in a growing market, there’s always room for fresh
innovation, and Kent-based product designer Stuart Lambert -
a self-confessed admirer of Brompton’s iconic folder - believes
he might just have identified a gap in the market.
Lambert’s story begins back in 2008 when, on holiday in
Bruges, he was less than impressed by the performance of a
rented folding bike. As a keen touring
cyclist, he began to think about whether
he could do better and address what he
saw as a clear trade-off between convenience
and ride quality.
More than 10 years and six prototypes
later Lambert’s vision has become a reality
in the form of the Crosshead, a striking looking
folding bike claimed to be compact enough for
city commuting but comfortable enough for
much longer rides.
As Lambert wheeled one of his bikes into
The Engineer’s London offices earlier this year
the first thing to note was its attractively utilitarian
frame.
June 2020 / www.theengineer.co.uk 30
As a product designer
Lambert has clearly put
some thought into the visual
appeal of the bike. But, as he
explained to The Engineer, it’s
the performance that’s really
important, and the sturdy
aluminium frame is key to
this. “When a bike frame flexes it can lead to reduced rider
confidence, especially at high speeds,” he said. “Our aim was
to obtain a precise and agile quality, which was achieved by
creating a relatively rigid frame. Through the use of aerofoil
sections we were able to add strength where required yet allow
for the integration of hinges into the frame sections.”
The frame folds (in around 20 seconds) around two hinge
points into a compact configuration described as the “z fold”,
which ends up with the two wheels folding towards each other
and ending up in a flattened ‘Z’ shape.
Lambert regards this as one of the bike’s key innovations.
“The aim from the beginning was to create a bike with a
compact fold without compromising the rideability or
performance. We achieved this by creating a double fold that
allows for a full-size bike to fold compactly,” he said.
The frame hinges are either entirely hidden within
the aerofoil sections or designed into the cast
joints making them relatively unobtrusive and
contributing to the sleek lines of the design.
The current hinge design has been present on
three previous prototypes and gone through
two separate CEN frame tests of 100,000 cycles.
Another instantly striking feature of the
bike when compared to other folders is its 20
inch diameter wheels, much larger than the 16
inch wheels used on a Brompton. “They roll over
road surfaces better than smaller commuter ones,
delivering a ride that feels closer to a normal wheel-
PRODUCT
DETA I ls
The bike folds
around two hinge
points into a compact
configuration
described as the
“Z-fold”
/www.theengineer.co.uk