From: jan@dcs.qmw.ac.uk (Jan Wysocki)
Newsgroups: rec.bicycles
Subject: Re: UK Track Bike  (Burrows Monocoque)
Date: 30 Jul 92 22:30:36 GMT
Reply-To: jan@dcs.qmw.ac.uk
Organization: Vision Laboratory, Queen Mary & Westfield College.

(Apologies in advance if this is a duplicate posting).

In article <redmondd.712277883@unix1.tcd.ie>, redmondd@unix1.tcd.ie (Judge Raz) wrote:
|> Any opinions on this bike. It looked fabulous on the track and helped
|> its rider, Chris Broadman, to set the fastest qualifying time with 4:27.357.
|> He was almost 3 full seconds clear of the second time. The designers reckon
|> that the bike is about 12secs faster over the 4+ minutes of the pursuit.
|> That time was an unofficial World Record 'cause it was outdoors (wind, etc.).
|> 
|> Judge Raz.

Until the Olympics we referred to this bike as the Burrows' or
Burrows/Lotus' carbon fibre monocoque.  Mike Burrows is an engineer who
runs a small engineering firm close to Norwich in Norfolk.  (That's
about 100 miles north of London.)

Mike has been designing and building 'funny bikes' and HPVs for over a
decade and is best known in the UK for his Windcheetah HPV, which used
to be the second fastest HPV in the UK, and the Windcheetah SL.  The SL
or 'Street Legal' is popularly called a Speedy and is a tricycle
recumbent with 2 front steering wheels and the rear wheel is driven.
The frame is glued alloy.  Front wheels are 17" Moultons on tandem hubs
with stub axles.  Rear wheel is 700C.  All controls are on a joystick.
On the flat and downhill, the SL goes like shit off a shovel, corners
wonderfully, and is great fun to ride.  Some Speedies, have a
fibreglass fairing that is reminicent of a WWII fighter aeroplane.

The original Windcheetah had a single driven/steerable front wheel and
2 rear wheels.  As it was only used for straight line events, a
steering angle of plus or minus 1.5 degrees was sufficient and allowed
the front wheel to be chain driven.

Mike has also been developing bicycles.  He originally started with
funny bikes for time trials, utilizing parallel seat tubes to shorten
the wheelbase and 24" front wheels for aerodynamic efficiency.  He then
started thinking of the possibilities of using carbon fibre and
honeycomb construction.  This method would allow a smooth sided
monocoque both for aerodynamics, stiffness and produce a natural
surface for logos, adverts, or what have you.  I believe that he built
2 prototypes which have most of the features of Boardman's Olympic
bike.  I have ridden the second prototype, which still had a 24" front
wheel and an early form of the current aero section bars.  By the
second prototype, Mike was confident enough to use stub axles and thus
reduce the drag due to half the forks and rear triangles.  As
motorcyclists with 'monolever' suspension systems will be aware, stub
axles make wheel changes a dream.

Since those prototypes, Mike has also produced several other
derivatives:  There's a small wheeled town bike on the same principles,
this bike is being produced in small numbers by another small company.
You can see him riding round Norwich on a 700C version, using Moulton
ball suspension at the rear.  He has also tried out a MTB version,
However, these town and MTBs have an offset rear wheel, for
constructional simplicity.  This offset gives no problems on metalled
roads, but produced an unsatisfactory ride off road.  Clive Sinclair's
Zike is also based on ideas provided by Mike.

His own carbon fibre bikes have been produced using simple hand lay up
techniques.  Boardman's bike has benefitted from Lotus's involvement
because they use vacuum moulding techniques for their car bodies.  As
anybody with a boat suffering from 'osmosis' knows, hand laid fibre
reinforced plastic contains numerous voids and fails to realise
anything like its theoretical strength or stiffness.  They also have
wind tunnel access and all the resources of a large technically based
company.  They're also interested in diversification.  I believe that
they now have some involvment in the vacuum moulding of GRP yacht hulls
and are also interested in the production of big ticket bikes for both
serious racing cyclists and poseurs.  I expect there also will be the
same sad trickledown to ordinary bikes that spawned the loathsome
'shopper' out of Alex Moulton's original suspension bicycle.  This sort
of construction technique is not suited to mass production, if you want
cheap hi-tech, you'd better stick with Kirk!

It was not certain that Chris Boardman would ride this bike.  There has
been some tedious wrangle between the British Cycling Federation and
the company that Chris rides for (I think it's Ribble Cycles, but may
be wrong).  The BCF's stated policy from before Boardman's selection,
was that it would use the Burrows' monocoque for the Olympics.
Boardman's sponsor's/employer (whatever - I've no doubt that someone
with a penchant for legal nicities can fill us in) were insistent that
he would ride one of their (conventional) bikes in the Olympics.  In
fairness to Chris, I imagine that he'd have won a medal anyway, but I'm
glad to see him winning a gold on a bike originating from someone who
has devoted himself for many years to bringing bicycle design into line
with the late 20th century.

Mike Burrows writes a regular column in 'New Cyclist', is a founder of
the British HPV association (possibly not the correct name, but it's
affiliated to the IHPVA), and has written for the 'Engineer' on HPV and
bicycling engineering.

-- 

          Jan Wysocki                 |  Computer Science Department,
                                      |  Queen Mary and Westfield College,
 email:    jan@dcs.qmw.ac.uk          |  Mile End Road,
'phone:   +44 (0)71 975 5230          |  London.  E1 4NS