There’s an aero component in the power-drag equation and a rolling resistance part. You know that the aero drag component varies with the square of speed (the power to overcome the aero drag varies with the cube of speed) but the rolling drag is constant with speed (the power to over the rolling drag varies linearly with speed). But the rolling resistance part tends to be small compared to the aero part. So that’s why I wrote the percentage time savings “is almost exactly” the same no matter the speed instead of “exactly” the same. The rolling resistance part screws up the exactness part. But we were talking about aero bikes so I was trying not to get into the rolling resistance part.
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But this would mean that there are people out there selling us stuff we don’t need…their whole careers dedicated to marketing products regardless of their value…
Pfft, that could never happen!
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Everything is marketed to us.
It’s not some grand conspiracy that the bicycle industry comes out with new models every year. Nobody is twisting anyone’s arm to buy a new bike, new wheels, a new iphone, a new car, or anything else.
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Out of interest do you have any comparable data for the CAAD12 with non-aero wheels? I’ve got a CAAD12 and wondering about upgrading the wheels on it.
You’re straying into the world of cost/benefit analysis - but imo you just can’t be objective. It’s a hiding to nothing. In the words of Revlon - they are selling hope, and it’s up to you to buy it or not.
Buy the bike you like the look of and enjoy it. Don’t sweat the small stuff.
Unless seconds matter to you.
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Yeah I wasn’t expecting such a long and spirited thread to be honest. Somewhere in it I did say if you’re competing and every second counts then they’re probably going to be worth it.
I personally just haven’t noticed much if any difference across my 2 current bikes and thinking about my previous 3 bikes.
Each to their own, ride what makes you happy.
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Moving to an aero bike took around 30 seconds off my times on the local 10 mile TT courses, other factors being equal-ish - power, equipment, clothing and the older bike had similar depth aero wheels. For me, as a road bike TTer, that seems a significant difference
Plus, it just feels quicker 
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Next time pick something non-controversial like disc vs rim or sock height 
But’s a reasonable question you’ve posed.
I look at it as someone who uses a tri bike regularly where I might save a fairly non-controversial 15 minutes in an Ironman by addressing the biggest issue in aerodynamics - even then am I sure it’s worth the cost of a ££££ bike?
But although I am somewhat cynical, I’m not downplaying those who have a different use case and different maths which makes an aero road bike worthwhile for them.
Yeah I use my aerobike with tri bars for ironman, I’ve bought all the aero stuff, helmets, socks etc in a bid to save a few a seconds when in reality I’m losing 15 minutes in the swim and probably an hour to the leaders on the run.
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These things are not mutually exclusive….you are not sacrificing your time on the run because you invested in gear to make you faster on the bike. The time saved on the bike is still time saved.
You can have marginal gains on the bike and still work on improving the other legs of the sport.
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Oh I realise that but I also realise my time and money would be more productive having some swim coaching and spending some time in the gym, but where the fun in that? 
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Money won’t buy you time on the swim, but it bought you a lot of time on the bike. On a long course tri (half/full), you’re talking minutes and not seconds.
The CAAD12 is faster than the new Orbea orca aero because the Orca is a disc brake bike and the CAAD12 is a rim brake bike.
They are both setup closely and similar positions, ive come across this same dilemma in that “I” want a new bike but I actually want to buy a fast bike so I am actually considering looking at old aero rim brake bikes.
Only fly in that ointment is my ironman was Bolton, UK with 16000ft of climbing and a very low average speed.
Sorry 12000 feet
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HAHAHAHA savage … but I mean, that’s very much so an exception in the long-course triathlon world. And then money could have bought you time, just had to buy a lighter bike/helmet/etc.
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Define “need”.
I hope you’re not suggesting lighter bikes are faster than aero bikes? World War 3 could break out here.
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That’s fishing for comments 
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My caad12 was much slower, even with fancy aero parts.
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