The Sukhoi has giant control surfaces and needs the best servos you can get. I had 5945s on the prototype and was using the plastic wheels with bolt-on arms (because they cam with the plane and I wanted to test them). Both the plastic wheels stripped thanks to Silversurfer's somewhat heavy-handed flying style.

From this I learned that for ailerons I'd suggest at least 5945s or preferably 8611a with metal arms.

Elevators are not as large as ailerons but still impose a huge load, same story there.

TF