of the tyres is to transfer the rotary motion of the engine to the
ground so permitting the movement of the kart and also to give direction
to the kart via the steering wheel.
As they serve two different purposes, they have two different sizes: the
rear tyres are of a greater surface area than those at the front.
As it happens, sometimes well-inflated tyres tend to grip better: this
is because when they are flat, they tend to grip the track only
laterally and not in the centre and so adherence diminishes. Incorrect
regulation of tyre pressure can also cause abnormal wear.
Wet weather tyres: in the case of a wet track ( or so declared), wet
weather tyres are obligatory. The tread of these tyres is very grooved
to improve grip when the track is covered with a lot of water, but they
should never be used when the track is only damp or even worse, dry:
they would wear abnormally and give very bad performance.
Putting on and taking off the tyres: This is quite a difficult operation
and in my opinion it is best to go to a garage. In order to take the
tyres off the rims correctly one must have adequate tools, as the cost
of this job is a reasonable one (when new tyres are bought often they
can be fitted free of charge or at a low cost in relation to the price
of the tyres), I don’t think it is worth doing it oneself as one runs
the risk of doing expensive damage.
Tips on taking care of the tyres and their lasting: tyres fitted on a
kart have a very variable life-span. This would be quite easy to define
but it all depends on one’s definition of life-span. As the tyres are
probably the features of the kart which make the most difference to
performance, one should consider their life-span as a period in which
they can offer the maximum performance. If one thinks that a race is
made up of around 15 minutes of free trials + 5 minutes of qualifiers +
about another 15 minutes of racing, one can deduce that the tyres offer
maximum performance for just over an hour of use. For this reason it is
advisable to have a series of “racing” tyres to be used solely in
competitions (when this becomes worn, move on to trial tyres) and a
series of “old” tyres to use at other times.
To lengthen the life of one’s tyres there are a couple of tips worth
following. The first is definitely not to let them slip too much whilst
braking (by blocking the wheels) or whilst accelerating (in power), but
also during lateral sliding ( too much counter-steering for example);
the life-span of the tyres is therefore closely connected to one’s
personal style of driving. The second rule is to avoid entering the
pit-stop lane (usually littered with debris and dirt) after having done a
few laps at high speed: in this case the tyres would be hot and “soft”,
therefore prone to damage from the grit and small stones on the track.
For the same reason, one should always use one’s kart in “clean” areas.
Finally, bumps, accidents, contact of any sort (even with the curb)
and going off-track, naturally will wear the tyres abnormally and can
often do serious and irreparable damage.
To go back to the original point, old tyres can be used till their end
but only if one is prepared to lose seconds on the track. On certain
tracks even old tyres make little difference: the strong grip and the
low speed at which most bends are taken, level out the difference in
times and in particular, these conditions weaken the influence of old
and worn tyres. Other tracks, with very fast bends, need tyres in
optimum condition if one doesn’t want to lose too much in terms of lap
Storage of tyres: they should be kept in black plastic bags in a cool
and dry place. If tyres are left in daylight, in too warm, too humid or
too dry conditions their characteristics will deteriorate rapidly.