Tyres - How Old is too Old?

[Johnnyflash]

Right, here's the scenario!

Had a track day a couple of months ago on my (new to me ) Crim. Really been struggling to get comfortable and struggled to get any grip , mainly from the front. It was pushing in every corner, running wide and i could hear it chirping away for grip mid corner!!!

Had the guy from SW racing check out the suspension. He backed off the rear (everything) and found that there was too much oil in the front forks. Managed to syphon some oil out of the forks and adjust the settings. Bike was 100% better for the last couple of sessions but still not what i expected.

Skip to the present day, I'm struggling to get comforatable on the bike at all, front feels like its "tipping in" constantly and feels like the front is going to fold( tyre pressures are checked and adjusted every week). I'm happy enough with the rear now, I'm much more of a front end rider anyway.

This it not high speed weekend twisty hooning, this is commuting everyday around city streets and some freeway work!

Is there a known front end handling issue with the 04/05 ZX10?

I've already decided to drop the bike in to get the front end set up again ( prob with Zenodamper) but wondered what are people thoughts on tyre mixing and age of tyres.

The rear is a week 26/2008 Michelin 2CT and the front is a week 08/2006 Dunlop Qualifier!!!!

How old is too old........... and will the age affect the grip levels?

[Wattie]

Front end chirping mid corner??? Wtf?

[MadKaw]

Yep, change the tyres..
Its a fine line to get a tyre that will do daily commuting with good K's and be sticky enough for the track. Perhaps get another set for track use.
Zeno will sort out the front for ya but you may need to spend on some internals. He did mine and its fine ( I do have ohlins internals and ohlins shock in mine though.....)

[Johnnyflash]

Front end chirping mid corner??? Wtf?

Some major brown leathers moments i can tell ya.....

[Johnnyflash]

Yep, change the tyres..
Its a fine line to get a tyre that will do daily commuting with good K's and be sticky enough for the track. Perhaps get another set for track use.
Zeno will sort out the front for ya but you may need to spend on some internals. He did mine and its fine ( I do have ohlins internals and ohlins shock in mine though.....)

Its a pain in the arse trying to get the best of both worlds.............. was think of a set of Michelin Power Pure 2CT or a set of Dunlop Sportsmax Q2's. I only have a 25km round trip to work, and commute about 3 times a week!

Dont mind spending some money on valving, not too keep on buying a full set of cartridges tho!
Thinking of getting a full on track bike anyway, but space where I'm living is an issue at the moment!

[RustyAs]

Can’t comment on the bike set up, I may be able to add some insight to the tyres themselves. In a previous life I was GM for a large Tyre company for a few years.

In short the age will affect the tyre performance.

Essentially tyres are manufactured around three areas of importance: Grip, Durability and Noise. Generally depending on the importance of one aspect, the other two will suffer. Tyre manufacturers balance these depending on the requirements of the consumers

The best grip is achieved with a soft compound, smooth or slick tyre on a flat dry surface. Obviously soft compounds wear quickly so durability is sacrificed heaps and noise levels are not to bad. Increase the hardness of the compound and grip is sacrificed, but durability increases.

Unfortunately we do not live in Utopia, where the weather is always fine and the roads flat and dry, so tread is introduced to the tyre to remove water from the between the tyre surface and the road surface. The introduction of tread does a number of things. One; lessens the surface area of total rubber on the road hence less grip, two; significantly increases noise level due to the leading and trailing edges and the configuration of the pattern and three; due to the leading and trailing edges of the tread decreases durability.

Without going into detail, manufacturers make tyres with varying compounds and tread patterns to suit the conditions of the environment the tyre will be subject to.

One thing in common with all tyres, regardless of the materials used in the compound, is that eventually the compound will go hard. Sometimes rock hard.

If we go back to the start, the harder the compound the less the grip, but the better the durability. When the tyres are hard from being old no amount of work will get them soft. You will temp increase but the compound will not soften to anywhere near the original spec. Also due to the hardness / brittleness there could be issues with the side walls.

One thing they will last, so if you are travelling on a long flat dry road, you will get great mileage. Just don’t try and stop or corner to hard.
I remember my father and grandfather putting tyres in the shed for a few years to “harden the up” so they lasted longer.

My advice would be if in doubt change the tyres. I never run a tyre that is over two years old. Not a problem on the bike or the main family car, but the wife’s or second car is usually the one running on older rubber.
HTH
Cheers

RustyAs

[robracer]

Bridgestone 003's could be an alternative if still available...... more track based but still ok on the road....... even in the rain

[bonester]

My '06 er6n bought brand new in '09 had LETHAL tyres on it. So scary I changed em before 2000km was up....Dunflops too.

[oldman]

Age also depends on manufactor date. Every tire has a manu.. date stamped on the side wall. It will be in a little rectangular box with a number something like 3409. the first two nembers are the week of the year and the second are the year manufactored. So 3409 would indicate it was manufactored in the 34th week of 2009. Always look for this when buying a tire. no point in putting a three or four year old "new tire" on your moto. Cheers.