Tire Life

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JRConck
Posts: 164
Joined: Mon Oct 12, 2015 1:44 pm
Location: Virginia, USA

Tire Life

Postby JRConck » Sat Feb 03, 2018 3:32 pm

So I still have not come to grips with modern tire technology.
From a practical (think cost) standpoint how do you judge that you need new tires /
I do not ride frequently, nor do I ride hard (even though the older I get the faster I was defintely applies).
Back in the day tires would actually turn blue and become rock hard.
i have a duromter and check using that, but what are general limits on tire life due to age ?
:?: :?: :?:

Yamaha179
Posts: 30
Joined: Sat Sep 12, 2015 11:08 pm

Re: Tire Life

Postby Yamaha179 » Sun Feb 04, 2018 8:31 pm

My experience over the past several years with Avon racing tires mounted on lightweight bikes, RD, TD, and RZ Yamaha's, is that an average rider can get a full season out of a pair of tires safely. A full season being four to five race weekends with practice and two classes per weekend. A class champion level rider might need to replace a rear tire, or even the entire pair, if he does more races. The tires I am talking about are the AM 22 and AM 26 models, non-DOT, racing tires. For easier riders, like when I was riding, I could carry over a set from one year to the next. First race practice was always run a little easy, for many reasons, but the Avon's always came back. We used 90/90 and 110/80, mostly, on the light weight bikes and had some well performing riders on the WERA circuit. We had no way to check other than our thumb-nail...
Lyn Garland

Twinshock750
Posts: 116
Joined: Sat Sep 19, 2015 10:54 am
Location: Auckland, New Zealand

Re: Tire Life

Postby Twinshock750 » Sat Feb 10, 2018 2:26 am

John

Dunlop have this page I have found: http://dunlopracing.com/technical-info/#HC which comments to their tyres on age and wear etc.

I tend to take note of production date and start getting twitchy about using them beyond a certain point, though one TZ rider in Aussie peeled on a branch new 0606 (ie Mid feb of 2006!)production date KR164 to his 350......and used it all weekend. Quite a lot older than I'd use! BUT as Kerry has said over the years, tyres, like beer hate heat, light and age. When stored in cold, dark for short time they will be best.

I've also come to the conclusion tyres while expensive are "cheap" a hell of a lot cheaper than broken bones, body work, helmets and DNF's so I tend to bite the bullet and rotate them more often these days. I also use tyre warmers for obvious warming process, but also reduce the heat cycles a tyre will endure.

Interesting point about durometers: Kerry bought a durometer and I used it extensively and commented as such a while back on another forum and got told in no uncertain terms that it wasn't worth the paper I wrote the numbers on - the commentary being that the rubber hardness when cold will be very different when warm - ie don't rely on it to "prove" one tyre is stickier than another.....lol, doesn't stop me using it though for comparative purposes!!


Al
Don't always believe what you think.

170plus
Posts: 141
Joined: Mon Sep 14, 2015 3:05 am

Re: Tire Life

Postby 170plus » Sat Feb 10, 2018 3:02 am

...interesting re durometers...have never seen a tyre that's harder colder than another brand, but softer when hot...some witchcraft in there somewhere..

Bud977
Posts: 122
Joined: Sat Sep 12, 2015 9:04 pm

Re: Tire Life

Postby Bud977 » Sun Feb 11, 2018 7:50 pm

Many tyres on the smaller bikes are quite durable these days and can last quite a number of years.

I've got a set of Pirelli Supercorsas on my VFR400 race bike. These were fitted in 2013 and have done the Island Classic a couple of times, a couple of One Hour races, some practice days and quite a few PCRA race weekends. At the last One Hour, I had a very experienced team mate who went out on the bike. I told him after the race how old the tyres were and he said he could not tell any difference from fresh tyres. I would still go out and race on these tyres now.

On my RD250LC, I change the tyres after 2 years of racing (approx 12 rounds) because I start to feel guilty I've had them on too long. Still plenty of grip and tread. I run Dunlop TT900GPs on that bike.

When I bought my Bimota YB8, I was so excited to see how it went, I went out to a track day on the 8 year old Pirelli Dragans. How did they grip and feel? No different to a new set of road tyres and balled up quite nicely.

As an overall picture, I would consider 1 year old tyres to be good, 2 year old to be OK, 4 year old to be 'have a go and see if they still ball up after a session'.

Don't worry about the tyres turning blue. I wouldn't go off rubber hardness. A tyre doesn't have to be super soft to grip.

Basically, I'd give an older tyre a medium hard session and see if it is still balling up. If so, it's all good. If it is super smooth, I'd be concerned.

JRConck
Posts: 164
Joined: Mon Oct 12, 2015 1:44 pm
Location: Virginia, USA

Re: Tire Life

Postby JRConck » Wed Feb 14, 2018 3:13 am

THanks for all the input. The tires on my 750 are just over one year old and have had a very easy life. similarly the tires on my Harris YZR are maybe slightly older. Tires on my Yamaha FZ1 street bike are quite old and I have not had any issues with them. :) :) :) I will use them again this year.

170plus
Posts: 141
Joined: Mon Sep 14, 2015 3:05 am

Re: Tire Life

Postby 170plus » Mon Feb 19, 2018 4:04 am

At the risk of disagreeing with Bud, I'm yet to be convinced that the visual condition of the tyre is that valid as an indication of its stickiness...I have recently used some old KR Dunlops, which looked the part, rolled up nicely - even making the rear suspension look good (which it certainly wasn't), but grip wasn't great. The feel of new tyres was definitely better - hard to describe, but more 'connected' to the road.

As Bud says though, the proof is in how they work on the day.

I am suspicious that, for those of us that don't ride quite so close to the edge as others, the grip available from less-than-new tyres is greater than the roder's capabilities. That said, I tend to change the tyres every couple of years, assuming wear rate is not a factor, as they are cheaper and easier to replace than broken parts/paint, etc!

Gerrit
Posts: 363
Joined: Wed Oct 07, 2015 11:02 pm
Location: Kingdom of the Netherlands

Re: Tire Life

Postby Gerrit » Tue Feb 20, 2018 11:26 am

Not to mention that new tyres are also cheaper than broken bones...........

170plus
Posts: 141
Joined: Mon Sep 14, 2015 3:05 am

Re: Tire Life

Postby 170plus » Wed Feb 21, 2018 3:45 am

Exactly Michel...the part I didn't mention...how are your bones?


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