Well you can't really remove all the loss terms like air resistance, rolling resistance, inertial effects, etc. If you did remove all those loss terms (like riding the bike in a vacuum with no rolling resistance, etc.) then any power applied to the drive train would eventually take you to an infinite speed or light speed or whatever non-reachable theoretical limit you want to impose.
Basically how fast you get the bike to go depends on the power applied by the cyclist and the power losses imposed by: aerodynamics, rolling resistance, liner losses (e.g. bearings, drive train), inertial effects (accelerating the bike plus rider mass), gravitational effects (conversion of kinetic energy to potential energy and vice versa due to elevation changes of the entire bike plus rider mass). These are the primary things that determine bike speed for a given power. To a lesser extent in normal situations gearing comes into play. riders can only coordinate their muscles so well so if you're dramatically under geared for the conditions you'll 'spin out' before running out of raw power. IOW, try to ride fast down a steep straight hill in your lowest hill climbing gear and you'll likely spin out before running out of raw power from your legs as you just can't coordinate your muscles to spin the pedals fast enough.
But in terms of generating or sustaining power on a flat road in appropriate gearing the major things are:
- Fitness in terms of ability to convert fuels and oxygen to power. This does involve muscle fiber types but to a larger extent it involves cardiovascular fitness, muscle mitochondrial density, muscle capillary density, O2 carrying capacity of the blood and other metabolic fitness adaptations.
- For very short intense efforts pure muscle strength can come into play such as standing starts in a large gear or in some cases sprinting, especially sprinting in a large gear from a slow starting speed. But for events over about a minute in duration pure muscle strength is almost irrelevant for cyclists. It takes roughly 50 pounds average force per pedal stroke at 90 rpm to sustain world class cycling power for a rider that weighs perhaps 150 or more pounds. IOW, even top professional cycling power levels only demand pedal forces that are a fraction of the rider's weight that they can easily move while climbing stairs or hiking uphill or other routine tasks. Basically for endurance events, even relatively short endurance events, pure muscle strength is not a limiter for healthy riders. Sure if you lack the leg strength to walk up a flight of stairs then that could be an issue but for healthy riders their leg strength is not a limiter outside of some very short duration and high intensity situations like very short track cycling events.
So speed can be limited by a lot of things but on flat terrain in most cases it's limited by aerodynamic losses and the rider's ability to generate and sustain power. Those are the two biggest items for road cyclists looking to go faster. And if the duration of interest is more than a minute or so the power generation side is dominated by sustained metabolic processes and things like VO2 max and power at LT not pure leg strength.
FWIW, John Howard broke 152 mph on his specially designed bike by drafting a vehicle out on the Bonneville Salt Flats. Notice the extra high jackshaft gearing he used to avoid spinning out and how close he stayed to his lead vehicle to stay out of the wind and reduce aero drag. http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
-Dave
