Originally Posted by
phrantic09
Wider tires with less rolling resistance, aero frame and 52/63 wheels that measure 35/34 externally allowing 28s to be pretty aero.
Aerodynamic frame stem and bar setup. I’d venture 10-15 watts less effort to maintain “fast ride” speed vs an 8 year old frame, even if it were designed with aerodynamics in mind.
Edit- referring specifically to the S5 here
Wider tires do not have lower rolling resistance unless they are over-inflated. Set tire pressures appropriately for weight load and 23-25c tires still have the lowest rolling resistance.
The difference between an old S5 and the most aero bike made today is less than the difference between a tight and loose helmet strap. However, that difference in aerodynamics isn't due to disc brakes, so old tech hanging on a new aero frame wouldn't give up anything.
And all this is ignoring weight - which might be limited by the UCI, but most cyclists aren't governed by the UCI. So if your closed course is hilly, I think you're misjudging the aerodynamic advantage and false rolling resistance claims of new bikes with big tires.