My dear bro! Jab GS (ya koi aisi bike) speed marti hai to sometimes saath banda bhi marr jata hai! :o
I lost my uni fellow in tragic bike crash, he was pillion rider and instantly died due to head injury (May his soul rest in heaven, Amen!)
It was heavy Honda CBR with good tires and heavy duty disk brake. In your case, this outdated bike should stay under 70 km/h. And if you push it so hard the needle reaches 90, then you should be more than happy!