Originally Posted by
cyccommute
Yes. Threads per inch. On the second question, are you asking if that’s 40 TPI average for the tire or if that is an “average” tire? If it’s the former, yes, it’s 40 TPI on average. If it’s the latter, a 40 TPI is an inexpensive tire. I’d say that an “average” tire starts at 60 TPI. A 40 TPI tire rides kind of harsh but is cheap to make and buy. More threads make for a more supple ride.
It was to tires in general. In looking at tires for sale I don't see that spec in the descriptions.