I will also add -
I used to be like you - ‘don’t buy speed, just train harder!’ and I did ok for myself on a legit Cevelo P2c with aero helmet. Usually a top 15-20% bike split in local and regional races.
Then I got the money last year to get the full aero setup - Premier Tactical with disc+88 wheels, latex tubes, Giro Aerohead, fast trisuit (Roka / Castelli) and aero hydration setups. My bike position didn’t change much - we mapped my old position to my new bike pretty much and it’s hard to go lower as I’m in-between sizes and don’t want 650c wheels for the smaller bike.
Contrary to my prior beliefs and what people say - it was an utter game-changer. First off, training with an awesome bike setup is FUN. Like so fun that you want to bike more and more, which makes you stronger and stronger. I’ve always enjoyed cycling, but when you’re rocking on the roads in Norcal and everyone is staring at your setup slack-jawed, or even giving you compliments at the stoplights (happens all the time, amazingly, here in Norcal), you just want to train more. Next - the aero benefits are real when you put it all together. My average speeds in Olys is 2.5mph faster than it was with my Cervelo P2c, and with only 20-30watts more power, which at 23-25mph, indicates much more of an aero contribution to speed than power. (Most calculators will say you will need 50-100+ watts to get 2mph at those speeds).
Seriously, if you’ve never tried going ‘all-aero’, you don’t know what you are missing, it’s that good!
What bike do you ride now?
You really think a P2C is slower?
Premier Tactical.
I get your point though and do agree with it in that it’s almost certainly all the other non-frame stuff I upgraded that added a lot of extra speed, and for sure the frame and clean cabling was only a small portion of it.
Still, my point that having a new FAST bike can’t be understated - it’s by far the most fun I’ve had in tri! It’s to the point that I actually get sad if I have to ride my road bike on a long ride outdoors (happened when my TT bike was undergoing some maintenance).
I can get that same road bike with all the aero upgrades to go nearly as fast as my tt bike, but in that case, there still is a noticeable aero time penalty from the road bike brifters hanging in the wind etc.