In article , Cub Driver
wrote:

Most FBOs do instrument
training in their 172s (and everything else) and therefor prohibit
CFIs from spining the crap out of the gyros.
I discovered this to be the case at Chandler. One of the reasons I
went out there was to fly a Super Cub, and naturally I wanted to do
the spin training in the PA-18 as well. But they don't allow the Super
Cub to be spun, for just the reason you advance.
At home, we're not permitted to spin the J-3 Cubs, either, but not
because of the gyros The feel is that the planes are too old.

It's not the spin that will damage the airplane, it is poor pilot
technique in the recovery that allows the airspeed to increase an pull
too hard in the level off.

If you haven't recovered an airframe in 20 years, you probably don't
want to spin it until you have stripped the airframe and examined it
carefully. Fabric hides lots of corrosion and cracks or breaks.