Originally Posted by
Schwinnsta
Is there suspension losses of efficiency due to bobbing of the shocks as there are with Moulton?
Yes, that will happen on any bike with suspension and is why lockout is a feature. I ride a Birdy and can modify my pedal stroke to minimize bob up to about 100 rpm but I get bob at higher cadence or when I go out of the saddle. As long as the pedal stroke is good, those losses are relatively minor. If your goal is going fast on a Birdy, the first thing to fix is the body position and the second is the gearing. Hitting 100 rpm on a 52/11 gear ratio is only ~21 mph.