A very common question that comes up in the track day world is when should you replace track day tyres? This question is born out of fear of old rubber causing a crash by suddenly giving up and losing all of its grip.
This fear in turn has people throwing away good part worn tyres when they’re still perfectly usable, just because someone said a new or part worn scrub tyre will only last a couple of days.
Obviously different factors come into play when talking about when to change motorcycle tyres, such as the riders pace (a super fast rider will get through rubber much quicker than an novice level rider for example), suspension set up, tyre pressures used, and how kind your right hand is to the tyres – along with other factors like tyre wear patterns.
In that case then it’s safe to say that there are no hard and fast rules about how much you’ll get out of a set of tyres. So just how long can a set of tyres be used? A lot more than you might imagine.
Can’t See Canvas? You’re Not Doing it Right.
I was once told a story about how an ex World Superbike Champion – turned track day instructor – ran a tyre right down to the canvas, noticed it when he came back in, then decided to go out for one more session anyway.
There’s no doubt in my mind that his supreme ability allowed him to manage the grip levels in a way us mortals couldn’t, but just knowing that he went out on it and came back unscathed puts things into perspective about when to change motorcycle tyres and where the end of life really lies. I would not recommend for one second that you take it this far though, I am merely demonstrating what is possible.
So knowing what is possible with the rubber of today, what signs do we want to look for to give us an idea on when to change tyres:
Things to Look Out For
Grip Levels/Movement – Can you feel the tyres moving around at all? Movement that wasn’t there before? This is a sure fire sign that grip levels are starting to decrease. The increase in movement will always be gradual and grip levels will never fall off of a cliff, so you shouldn’t find that all of a sudden your tyres have zero grip, unless of course you cause them to loose grip with bad technique.
Shape – Is the tyre losing its shape? By this I mean are you getting flattened sections of the tyre. The middle third on each side of a tyre wear down a lot quicker than the centre when riding on the track as that’s where you’re putting the bike’s power down, so if the tyre is becoming less round from the centre to the edge of the tyre, that is another indicator of when to change motorcycle tyres.
Tread depth/wear indicators – As we established above and how the top image shows, motorcycle tyres can be taken way past the wear indicators and the minimum level of tread. However if you are seeing the tread disappearing on the side of the tyre then this is around the time you may notice a gradual decrease in grip levels.
You Must Ride to the Grip Levels!
On a number of occasions I hear people say that they had a crash because the tyre gave up, this isn’t strictly true. In reality what happened was the rider wasn’t riding to the grip levels they had and even when they might have been getting signs of decreasing grip, they still decided to press on at the same pace or even try to go faster. Put simply, a worn tyre will still run perfectly happy on the track, just at a pace that’s slower than a completely fresh tyre.
You must try and be conscious to the signs of decreasing grip and ride accordingly. You may be thinking how on earth would you know, and in truth it’s something that only really comes with experience of riding on tyres that are past their best, but if you’re mindful of the fact that grip could decrease based on the criteria above then you will be well prepared to feel those early signs.
Next time you feel you need to replace your tyres just because your mate said you’ll only get couple of track days out of them, ask yourself do you really need to change them? Am I feeling any movement? Is the wear pattern smooth? Is there visible tread? Does the tyre still have a good shape? These are the questions you should be asking yourself to determine when to change motorcycle tyres.
Take the above advice into account and use your head when riding on track and you’ll not only maximise the time you get out of a set of tyres, but you’ll also minimise the chances of getting caught out on a set of tyres that are past their best.