Rule of thumb for CC-Neu motor heat?

[loa]

Hello,

Just installed my 2200kv motor in my Revo 3.3 conversion. I have decently low gearing for bashing (16/40 on 5S, with a MMM), and although the motor temps are much much cooler than the 9XL I had before, it still got quite hot after hard bashing.

I don't have a temp gun, but is there a rule of thumb (like: if you can keep your thumb on the motor for 5 seconds, it's ok) I could use?

Thanks

Loa