Originally Posted by
Darth Lefty
This is a long-running Surly road bike thing. Their trademark styles are large tire clearance but also level top tubes. So to make an acceptable stand-over, they push the top of the frame (both seat tube and stack) lower. Nevertheless they quote the seat tube size. A size 54 on this bike is 55.5 long, would be a 56 for the large brands.
If you correct for STA of 73.5, it is a 55 TT which is normal for 54, and their 56 has a 56 5 TT which is also normal.
They seem to be sizing everyone down for no apparent reason.