Technical radir slicks

What causes these slicks to get distorted in shape? I just picked up a pair that are really dipped in the center of the tread like this one pictured from speedway motors. I would think they could hold a normal shape better, even if they were not mounted/inflated.

 

So when you put tubes in them and inflate the tubes the tread is flat to the ground

 

Yes, try it you'll be happy.

 

I was hoping not to use tubes. Website say 4 ply sidewalls, tubeless.

 

I have a pair on my 32 and run tubeless. NO problems at all and they trued right up once mounted and aired.
Also...i've got a couple thousand miles on them now with some miles in the 70mph range...you'd never know there were cheaters on the car.
Ride and handle great (for a hot rod) and run true.
Granted...thats with no rain! Haha

Tony