Previously we spoke of the Mechanisms of Tyres and today we will bring the topic further by talking about the structure of tyres.  When we speak of tyres, we tend to focus on the topic of tread rubber, which we discussed in the previous issue, but the structure of such black and round tyres is also an important factor that determines performance. One may imagine the framework of a building when speaking of structure, but in the case of tyres it is slightly different, as tyres have air inside and must be pliable in order to maintain supple rides. Try to picture the roof of a dome stadium. The roof of a dome stadium is not only made with the material forming the roof, but also with a framework on which this material is placed. This is similar to how tyres are structured. You may not be able to get a clear picture with this description, so I asked Mr. Hamashima to explain the structure of tyres, which may be rather difficult to understand.  

“First, if tyres, which support regular cars or racing cars, were made only of rubber, they would be too soft like a balloon and unable to properly support such cars. Unlike buildings, tyres can not be framed with hard material such as steel. So instead, steel wires or synthetic fibers such as nylon or polyester wrapped with rubber are used for the framework of tyres. These wires or fibers should be placed properly on the tread or the side of the tyres to prevent tyres from becoming too soft like a balloon.”

Tires, which I thought were just black and round, are not just made of rubber, but are structured with various material to keep air firm and support cars, just like making balloons stronger by wrapping Scotch tape or masking tape around them.

Now, how is this related to grip?

“As I explained in the previous issue,” Mr. Hamashima continued, “tread rubber is what touches the road surface, and under severe racing conditions, it is important to structure tires stiff enough so that rubber of tread can display its best performance. We tend to think that grip depends on the softness or hardness of rubber, but in fact, if tread rubber was not structured properly, tyres can not correctly hold the road surface, which may cause uneven abrasion and loss of traction. This time, try to imagine a brick of Konniyaku jelly when thinking of tyres. Too much traction (grip) will deform the jelly and cause the edge to curl, but if you insert toothpicks into the brick jelly from both ends and make it stronger the jelly will not be curled. Perhaps this will help you get a better picture of how tyres firmly grasp the road surface.’

Does this mean that grip power can not be attained unless there is a good balance between tread rubber and structure of tyres?

“Right. Also, the structure of tires should be tuned to attain best grip, depending on the friction coefficient of each circuit, i.e., whether or not the road surface is slippery. When walking on a frozen road in the winter, you are likely to stumble if you walk with your legs stretched, but if you use your knees as cushion, then you is less likely to slip. In the same way, if you use tyres that are too hard on a very slippery road, you can not attain the desired grip no matter how much the rubber tries to hold the road. Moreover, because winning is the ultimate goal in racing, it is also required to select a newly invented light weight material for tyres and to solve heat problems to meet the required performance.” It was thought that grip depended only on the hardness of tread rubber, which is often described by terms such as, “soft compound” or “hard compound.” However, best grip can only be achieved by the perfect combination of tread rubber and structure.  I hope this issue has been equally enlightening for you as it was for me. Wow! The year is fast drawing to an end & I would like to take this opportunity to wish all my faithful readers MERRY CHRISTMAS & A HAPPY NEW YEAR. May the new year bring Joy, Love & Success to you and your loved ones.  Wait before I go here is a Great Offer that you will not be able to resist. Bye for now & drive safely. See you next year.    CHEERS!!!