Regarding fore/aft and knee health, I’ve never understood the reasoning. If your hip angle remains the same and you’re rotating around the bottom bracket, fore/aft doesn’t matter for your knees. If you alter the hip angle or change your effective saddle height, it matters.
Lately I was wondering the same. Starting situation: I have two bikes.
- One Allrounder (Canyon Ultimate)
- One Aero bike (Canyon Aeroad)
- Both have same frame size, same pedals, same saddle, same brake levers, same handlebar/stem.
- Handlebars both slammed without spacers below the stem.
So, the only difference is the frame geometry.
In the past, when trying to make the fit as identical as possible, I always determined setback and saddle height. That´s it. So my decisive factor was the relation of setback and saddle height. The difference in longer reach of the Aerobike (+6mm) was not made up by putting the saddle forward.
Of course, the aero bike being lower and longer, my hip angle decreased (noticeably). Now I am thinking, if it would be better to “rotate forward around the bottom bracket” in order to get a more open hip angle (similar to the position on the Ultimate, which I like). For this, I would have to push the saddle forward a bit and lose the identical setback positions.
I am not trying to get 100% identical position (then I would not buy an aero bike) but I would like to know what will be the better option. Same setback, same hip angle or a compromise of those? Of course the goal for the aero bike is pure speed! I often heard that setback and sadle height were the most important things, but I wondered if this may be irrelevant (like the KOPS method) and just an oldschool misbelief!?
Are there any thoughts/experiences on this matter?