Extract from www.tal-ko.com web site http://www.tal-ko.com/TechTalk.html
giving you loads of info on the new tyres.
Tech Talk - Dec 21, 2009
New Age 2010 Green Label Slick Tyres
Now that the new age green label Maxxis tyres are in stock at Tal-Ko and a number of traders let’s look at some more detail on how best to use them.
These new tyres have a much squarer shape compared to the old and this is especially noticeable at the front where there is a significant increase in the contact patch on the track.
Add to that a new ‘green’ formulation and a new modern type of construction and you see that these really are new tyres rather than just a change of manufacturing materials.
One of the characteristics of the new tyres is that they seem to warm up to operating temperature quicker than the previous tyres, especially useful at this time of year. But having said that they also performed extremely well during testing on one of the hottest days of the year.
It is worth making careful note of the fact that they not only vary in surface width to the old tyres, but that they are also different diameters. Not a huge amount, but enough to make some difference.
The exact amount will vary slightly according to the rims you use them on but on fairly standard size 130mm front and 210mm rear the differences were as follows.
The front tyre is about 2cm larger in circumference which will mean the kart rides a shade higher but little to fuss about. At the rear the tyres have a circumference about 1.5cm smaller than the previous tyres and that is enough to make a gearing change.
So remember a smaller circumference is basically equivalent to putting on a larger rear sprocket. In this case effectively about one to 1 to 2 teeth less on the rear axle sprocket.
However because there is no doubt these tyres do give more grip, you may well find that you are coming out of corners quicker and can therefore afford to go 2 + teeth smaller to gain maximum advantage.
The thing that is very important is to take into account the changes in set up you may need on your kart to gain the best performance from them. And of course something that will vary from kart to kart and driver to driver.
First thing to underline is that because these tyres have different construction you don’t need to run them at the fairly high pressures often used on the old green tyres, especially in cold conditions. It is suggested that 10 – 12psi is a good starting point and then you need to keep an eye on them to see how they are getting on.
Because they offer a significantly wider contact patch at the front it may well be an advantage to re-look at your front settings. For example previously some karts needed a few degrees of toe out to make them handle. I’ve known others that need some toe in. Both of those settings may now be closer to parallel because the tyres offer more grip.
So the real key point here is to really learn about the new tyres and how to get the best from them. Try different settings and take a close look at both lap times, driver feed-back and the look of the tyres to see which is the way to go.
How much faster are the new tyres? Well that is a subject creating a whole sea of mythical figures. Claims of two and three seconds a lap are just ridiculous unless they were previously using concrete tyres! Half to one second is about the mark, but again this will depend on track and chassis set ups etc.
The new tyres are on sale at £105.63 a set plus VAT and will be available from Tal-Ko from January 4.
Grahame Butterworth
Formula TKM Co-ordinator
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Tyre pressure in tkm by 'Nigeljarvis' (29 Jan 2010 @ 11:08)
