Can you define the problem a bit more? Sketchy how exactly?
Sounds like RealMan says, more likely a problem of body position than bike weight distribution. You weigh so much more than the bike that shifting yourself around makes a massive difference. More than a 100 extra grams in a tube could make.
Shorter stem or something, get your weight back. NOT more over the front.
Weight over the front only helps on long fast corners. Not (definitely not) on techie stuff.
Maybe on steep stuff but sometimes you don't want to be too far back on that stuff, just nicely balanced. If you get too far back on steep techie stuff you'll lose steering completely or flip off the back.