I'm bored at work on saturday . Anyone have a link to a good article about tires that explains things like heat cycling shaving etc. I don't know much on the subject and I'm bored. thanks


Modified by ILcrxsi1 at 9:50 AM 8/26/2006

 

I'm not aware of a link, but if you have a specific question we can probably answer it.

With some tyres, you're trading lifespan for adhesion. But with some, you actually get longer life with the shaving.

 

I just see things, like the tire for sale thread for instance, about "5 heat cycle's" and shaved tires. I have a rough idea of what heat cycling is but I don't understand the point of multiple cycle's. And shaving tire's I just don't understand at all. You can probably get better traction shaved but I would think tire life would be the trade off. Do tire's wear differently if not shaved? Why not just sell the tire's shaved already? As you can see I'm a noob so I was just looking for a general article on tires.

I forgot there is a wheel and tire section , but this is directly related to autocross though.

 

I believe http://www.tirerack.com has technical articles.

 

there was this good article in grassroot motorsports, maybe someone could dig it up because i don't know where it is

 

This should keep me busy http://www.tirerack.com/tires/...h.jsp

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ILcrxsi1 &raquo;</TD></TR><TR><TD CLASS="quote">I just see things, like the tire for sale thread for instance, about "5 heat cycle's" and shaved tires. I have a rough idea of what heat cycling is but I don't understand the point of multiple cycle's. </TD></TR></TABLE>
Racers will report the number of heat cycles that tyres have been through in order for people to gauge how much longer they are going to last. There are some very expensive competition tyres that will be worn out after six heat cycles, and not grip at all.

On the other hand, tyres like the RA1 might go a dozen heat cycles for some people.

To most people a "heat cycle" is a 20 min sprint session.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">And shaving tire's I just don't understand at all. You can probably get better traction shaved but I would think tire life would be the trade off. </TD></TR></TABLE>
This is going to depend on the compound. I do not shave my Toyos at all, but I only do events, not races. My time around Summit Point is usually right at a leisurely 1:28, and racers will be a couple of seconds faster and correspondingly harder on the tires. My unshaved Toyos seems to last forever.

On the other hand, if you are racing or significantly faster than this old man, you might get <u>longer</u> tyre life out of shaving the tyres. What can happen with a fast car and full tread is that the heat will not be distributed evenly, and the tyre will throw chunks of rubber out of the tread.

You can also feel the "squirm" on new, full tread tyres. This does not bug me much, because I'm old and slow anyway. However, if you're trying to win a race you might want to eliminate this occasionally disconcerting feeling.

 

I'm going to autocross the full season next year. I am going to get a set of tires and have them heat cycled. I'm looking at the Kumho ECSTA V710's in 205 50 15. They already have a 4/32 tread depth so I won't need to shave them. Will these last all season which would consist of 8 events 6 runs per event?

 

There are several variables like alignment, surface you drive on, tire care, driving style, etc ---- but I'd be dissapointed if they didn't last 8 events. I got 160 runs out of a set on a "stock" Mustang.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by George Knighton &raquo;</TD></TR><TR><TD CLASS="quote">Racers will report the number of heat cycles that tyres have been through in order for people to gauge how much longer they are going to last. There are some very expensive competition tyres that will be worn out after six heat cycles, and not grip at all.

On the other hand, tyres like the RA1 might go a dozen heat cycles for some people.

To most people a "heat cycle" is a 20 min sprint session.</TD></TR></TABLE>

There are actually two different ways the term "heat cycle" is used. George's definition - the process of getting tires up to track operating temperatures and then letting them cool down - is one.

The other is the Tire Rack's definition (below), as applicable to their heat cycling service. This involves simply getting the tire up to normal (i.e. highway) operating temperatures. You can accomplish the exact same kind of "heat cycling" as the Tire Rack's machines do (according to this second definition) by driving the tires on the highway for ~20 miles and then taking them off the car for a couple of days.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tire Rack website &raquo;</TD></TR><TR><TD CLASS="quote">

The first time a competition tire is used is the most important. During that run, its tread compound is stretched, some of the weaker bonds between the rubber molecules will be broken (which generates some of the heat). If the tires are initially run too hard or too long, some of the stronger bonds will also be broken which will reduces the tire's grip and wear qualities. Running new tires through an easy heat cycle first, and allowing them to relax allows the rubber bonds to relink in a more uniform manner than they were originally manufactured. It actually makes them more consistent in strength and more resistant to losing their strength the next time they are used. An important heat cycling step is that after being brought up to temperature, the tires require a minimum of 24 to 48 hours to relax and reform the bonds between their rubber molecules.</TD></TR></TABLE>