tire ratings

["Philip E. Barnes" <peb3@cornell.edu>]

For what it's worth, I believe the letter rating of a tire and it's
corresponding speed comes from the tire's ability to withstand heat.
Remember that as a tire rolls, it deforms, causing heat. The faster it
rolls, the less time there is for a section of the tire to dissipate that
heat.

Phil Barnes (peb3@cornell.edu)
Cortland, NY (nowhere near New York City)
'71 TR6  CC61193L (22 year owner)