New bike......different size!

I had my Bianchi Intenso size 57 for the last year which at 5’ 9" was too big due to me not having enough knowledge when it was sold to me. I have just bought a Trek Madone and it 54 so a fair big difference but feels like a better fit so just wondering will there be a period where my body will take time to adjust to the change in size. I obviously had my bars and saddle adjusted on the bianchi to suit me. Took my Madone out yesterday and I’m a bit achy today. Anyone any experience on this? Thanks.

This is natural. As hard as you might try to replicate your position from one bike to another there are going to be subtle differences that you will adjust to. Give it a week or two and your body will get used to the new setup. As long as it’s muscle soreness. If you’re experiencing joint pain you will want to look at tweeking your position to alleviate it.

I have been experimenting with different saddles this winter. Every time I change saddles, as hard as I try to get the same position as the previous one I tend to have soreness or tightness somewhere for a couple of days that I didn’t have previously. You wouldn’t think that a couple of millimeters here or there would make much of a difference but they can.