A Formula 1 wheel is a piece of art, its flanks a blend of curves
matched with a look of solidarity. Unlike many parts on a racing
car, it’s relatively easy to understand the job done by
a wheel, but the sort of wheel rims fitted to a Formula 1 car
are nothing like those on a typical road car.
Both are round, but there the similarities end. While weight
on a road car wheel doesn’t make much of a difference,
every single gram that can be saved on a Formula One car’s
wheel is vital as strength and durability are balanced against
lightness.
Each wheel is retained by a central wheel nut and receives
its drive from the hub assembly via six drive pegs. There
are 12 spokes, in six pairs, allowing hot air from the brakes
to be ventilated through the wheel. Great gains have been
made in this area over the days when cars ran with five solid
spokes on the wheel rim.
The brake calliper sits within three or four millimetres
of the inside of the rim, with the brake disc sited inside
this. At the outside edge of the wheel rim, the surface has
been shot-blasted to make it more abrasive at the point at
which it meets the tyre bead so that they can grip better.
“The first thing that needs to be understood about
a Formula 1 wheel is that there are dimensional requirement,”
“All wheels have to be 13 inches in diameter. A front
wheel and tyre assembly has to lie between 305mm and 355mm.
A rear wheel and tyre is 365 to 380mm. The diameter of a dry
tyre can’t exceed 660mm, with a wet tyre allowed to
be 10mm larger.”
There’s a further factor for the team to consider –
the shape of Michelin’s new tyres for the season. Once
this is known, the rim width can be finalised to bring the
wheel and tyre within the rules. This is why a team’s
wheels seldom arrive more than a few days before they need
to be packed for transit to the opening grand prix.
Team McLaren Mercedes’ wheels are accurately machined
from magnesium, a metal that’s chosen for its low density,
by the Formula 1 team’s Official Supplier, Enkei.
Thoughts of using aluminium are dispelled, because, although
it would be stronger, it would be too heavy. Carbon was once
considered as a possible material, but this was banned, and
all Formula 1 wheels must be metal under FIA regulations.
Monitoring the life of a wheel is vital, and this is why
each of them is crack tested after 200km. It’s rare,
though, that any wheel is used for more than 150km. Indeed,
if a race is a two-stopper, they won’t do any more than
100km before being removed from the car.
Providing a wheel passes the crack test, its life could be
as much as 3000km, but this depends, according to its weight
and the material out of which it’s built.
Once again, radically different from the sort of life you
would expect from a road car wheel rim, but this is just yet
another reason why Formula 1 is such as fascinating and highly-specialised
sport.
Technical Specification
Dimensions: Front 305-355mm; rear 365-380mm
Material: Magnesium
Number used per season: Up to 200 wheel rims are taken to
each of the 16 grands prix in the Formula 1 season |
