Introduction
Scalextric Car Restorations
has uniquely designed, developed and manufactures the MAX Grip range
of tyres for the Scalextric range of cars. All the Scalextric tyre
types and cars are covered by this range of tyres. This article explains
how this was accomplished and the best way to look after your MAX
Grip tyres.
The need for MAX Grip
tyres
It became very clear early
on that the tyres originally fitted to the Scalextric range of cars
have a finite life. The tyres can simply wear out, they dry out and
become hard, they can crack and in the worst case, fall apart. Also,
with the introduction of the Sport track system the older Scalextric
cars without a strong Magnatraction magnet couldn't be used as the
Sport track surface is much smoother than the classic track it replaced.
With these strong reasons
it was necessary to introduce replacement tyres for the Scalextric
range of cars. This new range of tyres also needed to give more track
grip than the original tyres to allow the older Scalextric cars to
be used on the Sport track without the addition of a Magnatraction
magnet.
Another common problem
is identifying which tyres are fitted to which cars. At the time of
writing there are 137 different tyres available to fit 1675 different
Scalextric models from 1960 to 2014, and they are all black and round.
At the time "Which tyres fit my Scalextric car" was around
half of the questions we used to receive at Scalextric Car Restorations.
Some information was available via the Scalextric Service Sheets but
very little information was available for the older cars.
Developing a Scalextric
tyre database
At this time we already
had a database of Scalextric cars produced based on the original Scalextric
catalogues from catalogue 1 in 1960 up to the present. We simply added
2 new fields to the database, one for the front tyres and one for
the rear tyres. For each new tyre identified a Master Sample was selected
and stored, a 3 digit tyre identity code was assigned. This code was
added to the database for each application. To populate the tyre database
we used several methods:
Developing the MAX Grip
tyre
With the tyre database
coming along and master samples of all the Scalextric tyres also underway,
the MAX Grip tyre material was identified. Only the material was of
concern as the shape and size of each replacement tyre was already
given by the master sample. After much research a 29 Shore A hardness
cold cure rubber material was identified and considered the best option.
In addition the "stickiness" of this material could be adjusted
in the tyre production process.
The tooling process was
selected based on the expected volumes of tyres needed. A flexible
mould material was selected that is compatible with the previously
selected rubber tyre material and predicted production volumes.
A method to quickly and
easily produce the production tools was developed and trailed. After
a few refinements a reliable method to produce the production tools
was established as well as a way to add tool identity markings.
With the material for the
MAX Grip tyres selected some prototype tools were made and sample
tyres produced. Several problems were identified and solved. This
included completely filling the mould cavity, setting the right "stickiness"
for the MAX Grip range of tyres and generally developing a reliable
production process capable of producing tyres at the rate of around
1000 tyres every few months.
Each production tool has
one cavity and can make one complete tyre at a time. Where higher
production volumes are needed additional production tools are produced.
Some of the higher volume tyres can have up to eight production tools.
Manufacturing the MAX
Grip tyre
Production starts by weighing
out the correct amount of raw material for the batch size, generally
enough for 20 to 30 individual tyres in one batch. The material is
thoroughly mixed and degassed in a vacuum chamber until all air bubbles
are removed.
Each production MAX Grip
tyre mould is filled by hand ensuring the mould cavity is completely
filled with no air bubbles or voids. The Moulds used for the MAX Grip
tyres are "closed moulds" which give 100% tyre detail including
the inside tyre wall. Once the tyre is fully cured the mould is opened
and the new tyre removed, any flash removed, the tyre is inspected
and placed into stock. The production tool is inspected, cleaned and
put ready for production use again. Production tools can be used 100s
of times over to produce 100s of production MAX Grip tyres.
All MAX Grip tyres are
produced by hand in the UK by Scalextric Car Restorations.

Maintaining MAX Grip tyres
MAX Grip tyres are designed
to give the best overall levels of grip on both the Classic track
surface and the Sport track surface. There are some points to take
into account when using MAX Grip tyres: