back of the truck that would extend from

roof level to ground level. The area of the

truck between the cab and the screen would

remain open. Using this fairing, the air would

be parted by the truck cab, collapse in behind

it and then be blasted out of the way again,

creating the biggest slipstream envelope of all

for me to work in. That’s the one that Jason

recommended we go for. The only problem

might be that the screen would create so much

drag for the truck that it wouldn’t be able to go

fast enough. Dave Jenkins reckoned that his

truck would be able to cope, so we got into his

workshop and rolled up our sleeves to start

building the framework to support the screen.

MIG Welding the Fairing

We did, of course, have a lot of help from the

team at Jenkins Motorsport in building the

fairing and from Jason Hill in working out how

best to support something that looked like an

advertising hoarding that would be travelling

at over 100 mph.

The steel sections that made up the framework

were MIG welded, an arc welding process.

MIG stands for Metal Inert Gas and it uses a

particular type of welding kit. MIG welding

works by supplying an electrical current that

arcs between the welding torch and the metal

pieces you are trying to join. It’s like harnessing

the power of a bolt of lightning. The heat that

is created, up to 20,000° Celsius – many times

hotter than the surface of the sun – melts the

two metal surfaces at the spot where you want

them to join. The molten metal fuses together

as it quickly solidifies again and the two pieces

become one.

The electrode from which the arc is emitted
also melts, helping to fill any tiny unwanted
deformities in the weld, and it is fed through

the welding gun as a long piece of wire made

from a metal that is compatible with whatever

metals you are welding. That accounts for the

metal part. The inert gas argon is commonly

used, doesn’t burn or react with the molten

metal and is sprayed onto the metal as the

weld is made to provide a protective barrier

that prevents any other gases or substances in

the atmosphere from contaminating, possibly

weakening, the weld. MIG welding is a fast and

efficient process that produces solid, strong

welds, ideal for supporting a huge flat board

against a ‘wind’ of more than 100 mph.

The framework was bolted to the chassis of

Dave’s truck, with Jason suggesting a couple of

extra mounting points where it might need to

be strengthened. Then the board was bolted to

the frame and the fairing was ready to be tested.

In the meantime, I had to sort out the other

essential piece of kit – a bike capable of taking

me faster than I’d ever pedalled before!

Above: At Pendine Sands I had to cycle through

a cloud of grit behind the truck, now painted black.

GETTING THE SLIPSTrEAM rIGHT    45