On the "right" side
(Sweden)
The flexiness is what I'm concerned about.. Yeasterday I took a new personal best to work (It's straight throu central Gothenburg, a total of about 35 crossings), my average pace was 31.2 kmh with a top speed on the flat of 48kmh (thats rougly an average of 19,4 mph and a top of 29,8mph). This is over 10,5km or 6,5 miles.
During just the first month with this bike I've cut the time to work with 4+ minutes! (The "old" bike was a medium sized Nishiski Hybrid with suspended fork weighing 16+ kg...).
So I wouldn't say I'm a slow rider, but maybe not a fast one either
What tubes are more important to beef up concerning flex? I don't want to go up more in tube sizing, keeping these sizes I should get a frame that looks like a 1" standard frame in size 52, but in size 58
Wall thickness is less important. I just want a bike that I can evolve on for the coming years, that's still lighter than others store-bought-full-carbon bikes costing 3-5 times more
(If weight was my ONLY concern, I would probably buy a chinese carbon frame. But it's not
)