If i can get 10mph i will do it for sure
And you can, but not with that gear change.
This is not covered by opinion, or experience, it's math.
3.90 ÷ 3.55 = 1.10141
If 50 was the highest safe speed before, and you change nothing else, the new safe speed is going to, exactly, 1.10141 × 50, or 55.070.
To get a different answer, you must do 1 of 2 things:
1. change something else
2. be wrong
