Originally Posted by
cyclotoine
If you are talking 1980 vs. 2014 and you are talking about actual geometry (stack and reach, head tube and seat tube angle, BB drop, fork rake, wheel base) these have hardly changed at all. The look has changed and the top tubes are sloped now, but the geometry has not. Not for road bikes.
Mountain bikes are a different discussion all together.
For road bikes the BIG changes are in materials, component technology (again materials, derailleur geometry, disc brakes, oversized axles, electronics), and aerodynamics.
I have a 1978 Trek 730 (it came as a 736). It is Trek's production racing frame.
For a 21" racing frame the seat tube angle is 73 and the head tube is 71.5 with a 41.5 chainstay length.
For a 21" touring frame the seat tube angle is 73 and the head tube is 71.5 with a 44.5 chainstay length.
It appears the 2015 Trek Emonda has a seat tube angle of 73.5 and head tube angle of 73 with a 41.0 chainstay length.