Using Wear Pins Or Wear Holes To Measure Nascar Rubber

Did you ever wonder why the rubber on nascar tires are blowtorched and scraped after practice laps and throughout an actual race?  Well we’ve got the answer to this interesting “Did You Know” question.  This method is used in order to get a measurement on how little or how much a tire is wearing down.

In Nascar the Goodyear tires that every team uses are smooth, which allows the race cars to get better gripping on the track.  Rubber is a great material for creating friction and that’s why race tires are made of it.  When a stock car is racing around a track at 180 mph the tires rubber actually begins changing form under the intense heat that is generated, and the rubber in return will take form around any protrusions or dips created from the contact between the track and the tire. For this reason every tire is built with five or six small holes in them, called wear pins or wear holes.

These wear holes allow you to go back, after the tires have been run in practice or race laps, and get a real time measurement of how each tire is wearing down.  Now because so much debris and old rubber has accumulated on the tires the only way to clear the surface of the tire itself, so that the wear pin holes can be measured, is by scrapping this debris off.  The easiest way to do this is by using a blowtorch and a scraper.

You take the blowtorch and use it to heat up the tires surface so that the rubber becomes soft and fluid like.  When the rubber is like this all it takes is a putty knife or a flat edge to scrape away all the build up so that the wear pins are visible.  This process is quick, intense and efficient like everything else that a nascar race team is trying to perfect on the track.