Thank you for your quick answer Ian.
I fully agree with what you said. It makes sense.
To tell you my story, I first used the Canyon's PPS that prescribed me a M size with short stem. Then I ordered the bike and received it two weeks ago.
I visited then a fitter that told me that he will fit myself on this M size bike but that my possition would be very agressive. The fitter was using two cameras that reproduces my avatar on a screen with all my body angles.
Back Home, I tested the bike alone on my Home trainer but found the position very agressive and had the feeling that the frame was too small. I saw as well the bike settings at their maximums (seatpost in a very rear position, aero bars out of their setting area very upfront and max spacer stack possible 50mm). The worst feeling was when I had the hands on the brake position. I had the impression to bend a lot my back.
That is why, I decided to send back the bike to canyon to change for a L.
My Seat height is 815mm. You will find attached photos of my settings on the M size.
For your information, I have planned my first IM this year.
Thank you again for your help.
Thanks for include more information. Just like doing a consultation before I start of a fit in my studio, I find the more info I get in this thread the better prescription I can make.
I believe that I know what you mean when you say "aggressive". I think that means our arm pad elevation is rather low. What really stands out for me are these things:
1) you had a fit done but the fitter didn't tell you your optimal Pad Y and Pad X. That disappoints me. I feel that is a number that a customer deserves to get when they leave a fitting. That's a number that we (athletes, fitters) live by and, as seen in this exact situation, would remove the guess work. Motion capture with cameras is cool but achieving "Reasonable Fit Expectations" is better https://www.slowtwitch.com/Bike_Fit/Road_Bike_Fit/Reasonable_bike_fit_expectations_3595.html
2) "max spacer stack possible 50mm" - hold the phone! The max spacer stack for the 2018 bike is 80mm (a single 60mm spacer + a single 20mm spacer). To be clear the 60mm spacer is a piece that does NOT come stock on the bike and has to be ordered when needed (I think it's $20 USD). The max Pad Y of a 2018 size Medium is 645mm with the rise base bar and 625 with the flat bar.
3) Seat post in the very rear position - oh boy. This concerns me. I haven't studied the bike yet but that seems like a very shallow seat angle and I'm concerned.
I came up with a Pad Y of 666 and Pad X of 505 using a formula I trust.
You've been dealing with the 2018 Speedmax SLX so for that bike... Size Large, flat bar, short stem, TSP (Team Switch Plate) and a single 60mm spacer. That prescription requires the additional purchase of TSP and 60mm spacer. If you when with a Size Large, short stem RISE bar, TSP then you'd only need a single 20mm spacer and three 5mm spacers - then you'd have additional purchase of rise bar and TSP.
If I've said anything in here that has left you curious please get back to me and I'll explain. Also, if you'd like me to flesh out the 2019 bike let me know, I'm happy to do it.
Ian Murray http://www.TriathlonTrainingSeries.com
I'm all about athletes mastering triathlon
Twitter - @TriCoachIan