I am a tad confused by the geometry on the Mk3. I'm going by the size matrix here:
http://www.sjscycles.com/Instructions/Thorn/Thorn_Nomad_Mk3_Frame_Size_Matrix.pdfThere appears to be less slope on the top tube and higher standover height measurements. The seat tubes are longer, the bb drop has been increased by 2.5 - 5mm but the seat tubes have increased by 65 - 95mm. The TT slope has been cut down from between 100 - 165mm on the Mk2 to between 70 - 100mm on the Mk3, also the size designations don't seem to add up. For example, the 620L Mk2 seat tube C to C is 520mm + top tube slope 100mm = 620mm, whereas the 61L Mk3 seat tube C to C 585mm + top tube slope 70mm = 655mm so what does the 61 in 61L signify? The 61L Mk3 has a 10mm longer head tube at 208mm as opposed to 198mm on the 620L Mk2, are the forks also 25mm longer making up the difference? At first, I thought it must be because of the seat tube and head tube which appear to protrude further above the top tube on the Mk3 than the Mk2 but no that can't be it, the measurements are C to C.
What am I missing here? First, it seemed strange and against Thorn's design philosophy for them to raise the top tubes.
Then, whereas the Mk2 range had 9 different lengths of seat tube with eight of the frameset sizes using Mega Oversized tubing and two frameset sizes being Standard Oversized tubing, all this was done for overall ride quality. Now the frame tubing is all Mega Oversized throughout the whole Mk3 range and with only 5 different lengths of the seat tube (the seat tube of both the S & L being the same length as each other for each size). That also seems to go against their stated design philosophy.
As I said, I am a tad confused. I'm hoping better and brighter minds than mine will be able to explain it to me.