I was wondering if Merlin measures center to center or center to top... I emailed them but no response. I found a Merlin works compact in a Large but cant get the messsurements right... Merlin says its a 57 vertical top tube. I ride a 56.5 top tube that is cetner to center with a 110mm stem, that is tradition top tube. I have never owned a compact before.. I was wondering if the fame is the same size I have..or do I need to find a M/L which says its a 56.5 top tube. How does Merlin messure these bikes?

I have a lot of material at home on Merlin measurements. I will post them tomorrow. Hope that helps.

I have a Works CR in M/L and an Extralight in 57cm. They have the same effective TT length of 56.6cm (center to center).

According to http://www.merlinbikes.com/images/2007/works/frame_geo_07.gif, the effective TT of the CR in L is 57.5cm.