Tire Guts

Component parts of a tire.

The other day I received a small envelope packed with a bunch of funky fibers and strips of rubber from Challenge Tires. They are most of the component parts of a tire, minus the bead material, which would be made of flexible strands of Kevlar and whatever else they throw in there to make a tire bead!

This stuff is the casing materials and tread material. I'll go through what it all is here for you.

• Starting from the upper left, the hairy looking bunch of strands is the fibers used to make a casing strong enough to resist blowing apart under pressure of the air and helps the tire withstand the blows received while riding. Without these nylon threads, your tire would come apart. Think of this stuff as the foundation of the casing. In this case, these are 60TPI threads. 
• Moving clockwise to the amber looking stuff, this is more nylon thread for casing construction. In this instance, they are 120TPI, the maximum thinness for nylon threads for bicycle tire casings. You can really feel the difference when handling these samples too.
• The white stuff is 300TPI core spun cotton. Think "Grandmas best table cloth". This is soft, luxurious feeling stuff. The cotton gives high end tires their super cushy, smooth ride feel. This is put together with the nylon threads to construct a high end tire casing. 
• Next up we have the middle, black, shiny looking material. This is 1 ply "green", (non-vulcanized), material which has the nylon threads in it to reinforce it. This is folded two to three times and vulcanized with a tread. 
• And finally, we have the tread strip which the rest is bonded to via vulcanization.

Obviously there is a lot of things missing here, such as processes and the aforementioned tire bead, but it is interesting to see and handle these component parts of a tire and know that tires are one of the most important parts of a bicycle.