Originally Posted by
ejewels
Hey All,
On a road bike, I've heard you never adjust reach by adjusting your saddle setback. I had a general body scan fitting and was told my setback should be about 3.25". My question is, do bikes within one size of each other (say 54 and a 56) differ with how much you'd need to set the saddle for/aft? In other words, say I had to set the saddle way back on a 54 to achieve the right setback
Sometimes. Seat tube angles often flatten as the sizes grow.
With a 73cm saddle height there's 1.2cm more setback with the saddle rails in the same location moving from a smaller size with a 74 degree seat tube angle to a 73 degrees.
Sometimes not. The range of angles can be very small on the same frame model - 74 degrees through a 53, 73 through 59, 72.5 for a 61.
Look at the geometry charts and apply the necessary trigonometry.