So many people in my class have headaches today including me , and I ' ve been like this since last week . Ugh . <| sep |> Is a 7 k selector for 400 topaz worth it ? I currently have around 570 topaz too <| sep |> Haha yup ! Howdy ! <| sep |> As I have seen the methodology of GME consider O 2 intake and CO 2 out . Which is okay but disregard PCranaerobic glycolyzis metabolic action what occures during high force low CAD same power pedaling and doesn ' t need any O 2 presence that ' s why will not change CO 2 out as well . Tipically on steady effort you start to move forward to this metabolic way when you go beyond threshold 100 % FTP . Maybe the terminologymethodology of GME is not accurate to help to give wise answers to this question . What I ' ve noticed in pro history as pivotal CAD stuff 2013 maybe 14 on Mont Ventoux , TdF , when Froomey drilled amazingly to breakaway from wheelsuckin ' Nairo . while the max force BW was similar the Briton able to output that force in 150160 rpm for 3060 sec generating extra power and went off . nobody can say it was sustainable , but while max force is there you can add more power w incremental CAD drill . maybe I digressed a bit