Tyres are possibly the most important part of a go kart, or any road going vehicle really. Tyres are what connects you to the ground and for that reason it is crucial for your tyres to be at optimum performance all the time. It doesn’t matter if you’re driving a 7 year old banger with a dodgy motor. If you have new tyres working well you can be quicker than the best drivers on new chassis with bad tyres, they’re that important.
Reading the Tyre
Knowing how to read the tyre properly is very important as it will tell you how the tyre is performing on track. This can be done by analysing the wear patterns on the tyres after each session. By doing so you can tell whether the tyre is at the right temperature and if all of the tyre is in contact with the tarmac. Ideally the tyre should have light graining spread evenly across the surface and be matte in colour. Any sign of blistering and the tyre is getting too hot and generating too much grip, eventually this will result in high tyre degradation and poor performance. At the other end of the spectrum, if the tyre surface is too smooth it isn’t getting up to operating temperature (you will usually encounter this when the track is damp) as a result, available grip will suffer. These problems can usually be resolved by altering the tyre pressures.
Tyre pressures are one of the simplest set up changes to make on a kart and are arguably some of the most important to get right as they can completely alter the way a tyre performs on track In terms of temperature and wear pattern. For example, if the tyre pressures are too high, the tyre will get too hot and blister as mentioned earlier in the article, likewise too low a pressure and the tyre will not generate enough heat and grip. Logically, the more of the tyre surface that is in contact with the tarmac, the more possible grip. This can be altered with tyre pressure as a drastically overinflated tyre will have a narrow contact patch in the middle of the tyre whereas at the other extreme an underinflated tyre will be in contact with the road near the sidewalls. When setting the pressure on cooler days, you may have to raise the pressure to get the tyre up to temperature, sacrificing contact area as a result.
Like every component of the kart, your tyres need caring for. It is always a good idea to brush off any excess debris from your tyres (grass, gravel etc.) after each session. This will your tyres come on quicker next session as well as prevent you working any small stones into the surface which could cause a puncture. When new, tyres come in plastic wrapping which preserves the oils in the rubber during storage, if you won’t be using your tyres again for a prolonged period of time it might be a good idea to wrap them up in cling film to help preserve them for next time. Remember when storing to keep them in a cool, dry place which has fairly consistent temperature. A garage, for example would be unsuitable during winter because the contrast between day and night temperatures is large enough to effectively put your tyres through heat cycles, hardening them up.
Saving your tyres
As we know from Formula one, it is important to save your tyres, maybe not in a clubby at shenny, but in major championships you can be using the same set of tyres for a couple of days where the warm temperatures and rubbery tracks can really take it out of your rubber. We caught up with Gary Catt who taught us the importance of saving your tyres.
“I was renowned for destroying tyres… Especially in the days when we used bridgestone special tyres for all major races. I was always good at getting the most from the tyre when it was new and managed to qualify pole in championships but tyre wear was probably the biggest reason why I didn’t actually manage to convert those poles into wins”
Jordan Lennox Lamb on Tyres
Unfortunately due to the tyres we are using today there is no tyre saving at all. We are literally flat out from qualifying till the final. A couple of years ago when we still used the Bridgestone special and the Vega yellow it was a key aspect. I loved having to plan your weekend and not just drive like an animal from lap 1 to lap 25. Personally, I found tyre saving relatively easy, it was one of my advantages as a driver. It is all down to feeling, the chassis must be perfectly set up for you to really make a difference.
The best way to save your tyres in in the braking zone, so that you are never forcing the front tyres. Then it is all about when you are getting on the power, especially at la Conca where the rubber can to really build up on track. On grippy surfaces such as these the trick is to be on the throttle as soon as you come off brakes, only hold off the throttle for a fraction of a second to save loading your tyres but to avoid losing too much time. Always remember to be as smooth as possible when doing so as sliding will scrub your tyres and speed.
Words by Michael Killingworth