I am changing my Ultegra Rear cassette from 12 – 23 teeth to 12-27 teeth. This change is primarily for hill climbing. One thing I am working hard on is getting used to doing high RPM’s on my bike. Lower gearing, high RPM improve hill climbing. To do this, I will need to have good gear ratio and practice maintaining RPM’s on my stationary trainer.
I plan to have my seat, bar & stem adjusted/replaced after my bike fit. Making proper changes before winter training schedule will help me concentrate on training.