I have a tax return check burning a hole in my pocket and I am looking at getting a new set of NT-01s for track use. I have found a pretty good deal so I am looking at buying a new set right now, even though I know my schedule will not permit a track day until the fall. Do these tires age/get hard any appreciable amount before getting heat cycled from driving? I have had luck with my current set of NT-01s that only got used once a year over a 4 year span and they did not seem to get hard like I have experienced with other tires in the past. They would be stored in fairly cool 50-70deg temperatures and out of direct sunlight until I am ready to mount them.

I do not want to buy a new set just to have them lose a significant amount of performance before I use them. If that's the case I would just risk paying full price when I actually need them.

 

I suspect you would be fine as long as they aren't exposed to extreme temperature changes in that time. This is from Hoosier's spec catalog, and I'm sure its applicable to NT01:

"Service Life for Race Tires: Old tires can fail in use, causing loss of vehicle control and personal injury. Environmental conditions like temperature extremes, exposure to sunlight, electric arc, solvents, automotive fluids, and atmospheric pollutants accelerate the aging process. Hoosier Racing Tire strongly recommends that new (sticker) tires should be put in service within 2 years of date of purchase. Used (scuffed) tires have a shorter service life than new (sticker) tires. Poor storage and infrequent use accelerate the aging process."