I am looking around for a new bike because my current one is really too large for me, especially because I want aerobars. Which is too much of a stretch now: my saddle is currently all the way forward and I had to install a steep angle headset to get the bars closer to me to get comfortable. Also, seatpost is almost all the way down.

So this new bike I have in mind – the measurements compared to my current one are as follows:

The size “SM” is recommended for inseams 80-84 cm.
Top tube 54 cm, Down tube 53 cm.
My current bike has a 56 cm top tube and a 54.5 cm down tube.

This is only 1.5 and 2 cm difference, respectively.
My inseam is 82.5 cm (I’m 5’10’’ or 172 cm)
Will this really improve the fit for me?

Or should I try the S also?
The “S” size is recommended for inseams up to 79 cm
This has a 50 cm down tube and a 51 cm top tube.

This is a men’s bike. So how much does make a difference?