I went to a Trek store this week and they have some kind of sizing computer in the store that takes your picture and then it recommended an LG bike. I rode both an FX4 LG and XL FX3. In truth, I did not notice a huge difference between them and I think I could have been comfortable on either. The feel was much less different than I had between the Lg & XL Verve and seemed more comfortable than either of those. If I look at the specs the reach is the same on both sizes and the standover was the most noticeable difference and the LG was more comfortable with the XL putting me on tippy toes and still being high. The LG FX4 had seat in the upper half of its extension range but nowhere near the limit, so all seemed fine with that bike and is the model I wanted to start with. I would have been looking at 2022 for an XL FX4 and the LG was ready for me to take home I pulled the trigger and am now officially the proud owner of an FX4. It was the end of the day and I skipped doing a lot of outfitting, opting only for a couple of simple bottle cages and a Duotrap Bluetooth/Ant sensor since it seemed easier to have them put it on. I ordered a pair of Shimano SPD/Flat pedals to put on since I am used to clipping in on the Peloton and want to be able to do it on this bike. It has been cold and rainy here so I only took it out for a quick 35-minute ride the other day, I wanted to go further and could have physically but my hands were freezing cold and I decided there was no sense being uncomfortable when I had a nice Peloton to ride in the comfort of home.
I am not sure I am using the correct words, but I believe the problem was the weight on my hands and I think I am now succeeding in putting my weight on a good point of balance like discussed in the Hogg blog. My position on the FX4 feels similar to my Peloton riding position.