What happened to the bike?
The saddle moved forward towards the bottom bracket
The reach to the bars stayed the same in many cases but the ability to maintain a neutral spine position easily and subsequently longer back meant a longer reach.
The handlebars moved further forward away from the bottom bracket in both cases.
A lower handlebar and more aerodynamic position
How does this influence bike design?
The Seat angle is steeper
The front centre is longer (i.e. the front wheel is further forward from the bottom bracket).
It is not possible to change the frame’s geometry
Assuming the best fitting frame size has been selected it is possible to get a very good fit by adjusting the saddle and handlebar position.
Seatpost setback has to be reduced by using an in-line or zero setback seatpost and in some cases sliding the saddle forward in the rails. Apart from being highly unattractive it moves the rider away from the back wheel.
The stem is lengthened and the rider’s weight is forward over the front wheel so the bike is front loaded which can affect handling and control.
It is possible to change the frame’s geometry.
The frame is designed exactly for the rider, no need for compromise.
The seat angle is steepened to fit the saddle in the centre of the rails, we often design a frame for a tall rider with a 74 degree seat tube where a stock frame would normally be a more relaxed 72 degrees.
Chainstay length is adjusted to maintain the relationship between the rider and the back wheel.
Top tube length and the ‘trail’ (the relationship between the fork rake and head tube angle) adjusted so the rider’s weight isn’t too far forward over the front hub.
Stem length selected proportional to rider and frame size
Desired handling and riding position is built in to the bike
The future of bike design
In a nutshell, the seat tube angle needs to be steeper and the front wheel further forward from the bottom bracket. It isn't a big change, it's just a tweak and most people can ride most bikes, I'm just being finickity.
Change is expensive though, it’s all about the cost for the big bike manufacturers, they have decades of bike production, thousands and thousands of happy customers and hundreds of thousands of dollars of investment in the molds that make their carbon frames; why should they change their designs?
Which company would be the first to change? Is it worth it? It’s a big risk and if one bike model changes in a range of forty models so must all the others in all the sizes. Maybe on their 'performance' bikes a few changes could me made with a gradual filter down through the range.
So what can they (they being Specialized, Trek, Cannondale, Canyon etc) do in the short term to their bikes while the designers stroke their beards and the accountants look at their cash flow?
Make zero setback seatposts standard spec on the bike (especially on aero race bikes)
Drop crank lengths down a size across the range to keep the hip and knee angle more open and don’t bother with a 175mm crank on anything. On women’s 44cm and 47cm frames spec a 160mm crank.
Easier gears for all of us – even on Dura Ace and SRAM Red – so we can maintain a high cadence with those short cranks on the steepest of climbs.
Make saddles that are more comfortable at the front so it is easier to rotate the pelvis forward (this is a major issue for women cyclists and middle aged men).
Design forks that can tolerate a higher stack height than 3.8cm (this isn’t really related to the subject but I thought it should be mentioned as head tubes are still too short for most riders).
PS. Did you notice Bernard Hinault's saddle height is too high? No wonder he had bad knees.