I'll go for 27.2mm
I think it will look much cleaner.
Yes I could make it like PROTO-TYPE 3, but somehow prefer a frame with seatpost. Don't get me wrong, how I made PT3 was great, but only for one person, for a specific pair of shoes and pedals etc.,..and you can't give your bike for a test ride if it's integrated like that, and I prefer that I can change the position and give it for a test ride to my friends etc.,...the other thing that I saw by my PT3 frame with completely integrated saddle was that when I changed my shoes (years ago we rode Sidi, then Northwave, then DMT, and now I have Sidi,..) those shoes are all a bit different, and it's nice if you can change the position a bit, also if it's only -/+ 3mm. And then if you change lets say from Look to Speedplay you'll again have a few mm of difference..but in general the idea is for sure great and also saves around 40g (compared to the seatpost in the frame + seatpost clamp).
Also for the internal routing I'm not quite sure if I'll make it internal or external, will see. EE brakes would be great, but will see how I'll build this bike (depends of course also from $$). I won't really rush with it, but will most probably just swap the parts from my PT4 bike for this year. I'll for sure change a few parts, and it won't be really WW friendly
. Somehow I miss ALU handlebars and will most probably go back to ALU. Right now I have Ritchey Superlogic UD, very light handlebar (188g if I'm right) it's great but it's not as stiff as ALU...so I'll most probably go back to ALU and add around 50g, can't help myself, I just prefer it like that because I'm used to it (raced with ALU for 10 years).
But don't worry, I'll for sure build a good and light bike
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