I’m currently in the process of sizing up a new bike and was a little confused with Trek’s geometry chart.
Source: Trekbikes.com
N = Frame stack
M = Frame reach
Specifically ‘Frame Stack’ appears to be measured to the center of the stem stack not the top of the head tube which I understood to be the convention. I’m assuming I am missing something or it’s just a badly drawn chart. Stem stack is after all a moving target dependent on the spacer stack.
Is someone able to clarify this?
I’m trying replicate the position of my Cervelo S3 which has a stack and reach of 585mm (560mm) and 591mm (394mm) respectively on a 56cm frame. Figures in parenthesise are from Cervelo’s geometry chart. My stack includes a 15mm top cap and one 10mm spacer. I’m currently using a 120mm - 6 degree stem and compact handlebars with a 77mm reach.
Assuming Trek measures stack to the top the head tube I’d go with a 56cm frame in a H2 fit. The frame stack is 577mm and reach is 387mm. The Emonda uses a Cane Creek AER headset which has a ‘short’ 9mm top cap. Slamming the stem saves another 10mm. Overall that leaves me with a stack 2mm taller and reach 2mm shorter than my Cervelo, using a 120mm -6 degree stem. The Emonda has a 73.5 degree head tube compared to the Cervelo’s 73. It’s close enough to make only a minor difference.
Why not the Domane or Madone? I don’t like the slightly disconnected feel of the Domane and I don’t want the additional maintenance overhead of the Madone’s BB mounted brake and it’s reduced braking performance.