You have what is most likely the worst 'linear pull' brakes on the planet. They are nearly impossible to keep adjusted properly. Get some decent brakes and they'll be much better. You won't go 'flying over the bars' if you know how to use your brakes. Do you lock up the rear and skid every time you use the rear brake? Millions of people use linear pull brakes and don't go over the bars. Millions of people use disc brakes and don't go flying over the bars. What is with this irrational fear of front brakes?