That failing BB will be stealing a little bit of efficiency, and servicing or replacing it might help in regards to effort-expended-per-pedal-stroke.

Sheer speed is mostly the product of the "motor", in bicycling. Weight means very little as far as top speed (on level roads) goes; it just might take a little longer to get there. More important factors are Aerodynamic resistance, frictional losses due to rolling resistance, and gear selections that allow you to pedal at your most efficient cadence.

It takes a very strong rider to turn over a 53 X 11 at any kind of cadence....