Hey, thanks for the friend request! Hopefully you found my rate helpful :)
Although after taking a second look, I noticed you were running a more offensive version of ChopleTar. So, I took the liberty of doing a calc for you!
Standard 252 SAtk Timid Thundurus (+2) vs. Brave Tyranitar 252 HP/80 SDef w/ Chople Berry:
314 - 370 (77.72%-91.58%)
So, after some previous damage (SR and a layer of spikes), you'll be in danger of being OHKO'd by a +2 Thundurus. So if you face one, be sure to get in before a boost, or just run more SDef EVs. Hopefully this helps!