Dont have a tempest but i do have a london road. 6’1 with 34 inside leg and ride XL. Feels pretty stretched and whereas i’d normally run a 100mm stem 80-90 does for the london road. Other than that it’s spot on for me.
Got a mate rides another planet x – cant remember the model. But, similar build to me. Riding a large and finds it cramped.
Check out geometry geeks for their geo comparisons. You can choose bikes to compare and I know the tempest is on there cos i’m looking at the same bike…in XL!
I can generally ride a 56 or 58 or large depending on brand and geometry