30 Watts for legwarmers? At that low power. Where does that come from?
Certainly is not correct.
A loop, unless it is a velodrome, is a very poor way of measuring aerodynamics. You have several changes in wind direction, corners that it is hard to always maintain the same speed and line throughout.
Always test in a straight line where you know that direction and distance (because a few meters make a difference) is the same for every run. Also, 2 Runs mean nothing. The variance between runs of the same equipment can be greater than the difference between equipments.
Problem in the world tour is, that they ride in the shelter of the peloton most of the time, so the overall power required is much less. And 8% difference in drag might only be 15 to 20 watts in that case.
Also, no one rides a SystemSix with 64mm deep wheels or an S5 with 62mm deeps in the world tour, in the same race where people ride a TCR with shallow rims. That decreases the difference once again.
However, WT pros are not taking the smartest choices, so I would advice against holding their material choices at such high standard.
This has always been my theory as to why road race pros don’t generally ride aero bikes. When you spend the majority of the time of your time drafting, it’s less of a factor.
There is a few reasons to not choose deep dish wheels:
the Race (so the part where you try to beat others) is only up Mortirolo or Zoncolan, so you never exceed 15kph.
there is absolutely awful crosswinds (which is a reason for me to go 51mm, not go box section)
one of the important parts of the race will be a technical decent, that is decided on stability over efficiency
your Sponsor makes really awful deep section wheels (like lightweight)
you don’t care about factual gains, but just want what feels better/ more responsive/ more stable
My guess is 90% of WT pros choose shallow wheels because of reason 5.
I mean, they race stages with flat breakaways, monuments and sprint finishes on 30mm wheels, which is surely not the most efficient thing to do.
Since they all do it, there is not real loss there…
Hmm, the last 50 miles or so in any of the classics there is no peloton and when you’re in a small group working, imagine if Greg say had to do 360 Watts and his competitors were only doing 330. He would never win a thing… With regards to my testing loop, it’s actually a perfect circle so there are no corners and it allows wind to go through 360 degrees of yaw so you get to test every yaw angle. The 30 Watts is from the Specialized win tunnel tests that tested bare legs vs hairy and there was, I think, a 30 watt difference. I am assuming that leg warmers are as aero as skin (skin being not as aero as fabric usually). The reason I test at 250 Watts is it’s an easy power to keep dead on.
And how many races Greg won since his team went for Giants?
And for your 30W difference, I suppose Specialized refered to the speed of 45km/h as usual, but normaly 250W gives you something around 35km/h on the flat (depends on your position, helmet, clothing…)
But yeah, if you don´t want to spend crazy money, just work on your position, that is for sure. If you want to buy some speed, get an aero helmet, tighten the helmet straps and take an aero jersey or even a race suite
BUT, when your aero bike looks aero, you feel aero and you are certainly faster add some nice deeper carbon wheels and nothing but their sound will make you feel amazingly fast…
I have all of the above listed things. I was surprised that I saw no difference form something that supposed to be somewhere between 15 and 30 watts. I have actually tried adjusting my watts up and 20 extra watts does reduce time. 2nd in Omloop and San Sebastian on the Giant are certainly more impressive than my Palmares, don’t know about yours!
The 30 Watt difference is with a Giant TCR vs the fastest aero bike out there, with 64mm deep section wheels… No one in classics rides bikes like that. If you take away the deep section wheels, and the aero handlebar, that is 70 to 80% of the difference right there.
Giant bikes aren’t bad, but the set up they tested (Tour Mag) is slow compared to aero bikes. That is very likely true.
Testing loops are always difficult. Even when riding on a track, the difference can be a few meters for not holding the line properly. On an outdoor loop, that is almost impossible.
Aero testing is a very difficult topic, and requires many runs, and a lot of diligence.
15 Watts difference at 45kph (so at 400 to 450 Watts) from probably very hairy legs to perpetual shaven legs. I think that is absolutely realistic.
I have to disagree that aerodynamics is about feel, rather lightweight. People build up 5 to 6kg bikes, lift them and marvel at how light it is. Now they plant their phat bum on there (even if you are 60kg), and suddenly, you have saved 1kg (over another bike) on a 68 to 90kg system (inkl rider, bike, clothing, water, spares), which is 1.5% saving at best, and closer to 1% saving at worst. That means 1% saving on the your Crr when riding on flat and undulating roads (so 0.1% saving of total power), or 1% saving on a steep climb on your W/kg (so around 0.7% of total power). If anyone can really feel and measure that, I‘d be very surprised.
With aerodynamics the margins are quite a bit larger.
I still agree that the main thing that a bike should do is allow you to stay in a position that you can produce the most W/CdA in. But aero wheels etc are regardless of that and just make you faster…
Same with Cervelo and the S5.
Riders choose the bike that they have ridden all their lives (which are usually lightweight bikes), because they feel good and comfortable on them. With everyone doing that, it doesn’t really matter.
However, in non-sponsored racing, where people can freely choose their equipment, you see a lot of testing going on, and there actually being noticeable differences. Not as noticeable as a strong rider vs a weak rider, but noticeable enough to tell apart two riders of equal capability.
It’s all very interesting. I’m not a pro cyclist but I am a professional photographer. When you’re on the internet looking at what (genuine) tech specialists talk about with regards to cameras and various advantages each has or hasn’t got they always miss things that genuine professionals know. I wonder if that’s what’s going on with pro riders. They know things at a level the tech people don’t. For example, quite a few Deceuninck riders ride a standard cockpit instead of the aero one, why are they giving up 15 watts? There must be a reason, maybe it isn’t actually 15 watts in real terms, I don’t know but there’s something they know and we don’t know and bike makers/sellers want to keep it that way.
I suspect that some pros (just like some amateurs) are very conservative, and choose what they know and trust in pressure situations. You see it all the time with pro golfers using older models of clubs; they like something they know has worked, and - perhaps most importantly - they like the feel. That to them is worth losing a few meters/rpm (or whatever else matters to golfers).
This extends to more than just aero stuff on bikes. At the risk of opening a can of worms, why would any pro, choosing purely intellectually, use rim brakes? All the manufacturers can get down to the UCI limit with disc brake bikes, so it’s not that; they’re not paying for their bikes, so it’s not that. It can only be feel and what they are comfy with.
I have been saying this for years: saving a few hundred grams on a bike is almost totally irrelevant unless you’re a top level hill climb specialist. I guarantee getting someone on a bike that truly fits them will make far more difference to speed than losing a whole kg of weight. If you can get them much more aero as well, that’s probably worth 2kg of weight.
I do believe people genuinely do think they can feel the difference, and maybe, in a few seconds of sharp acceleration, they can, but they don’t understand that feel isn’t real, and what makes them truly faster is that 0.5-1km/h up that drag, steady pedalling on that flat section, down that short descent, which they don’t notice but which really add up over a ride.
But, I do think you have to be quite a quick rider for it to be a game-changer. Sadly, as someone who usually averages c.29-30kph over 80-90k, that’s not me (yet)
They tested bikes used in the world tour in this one test. There are numbers on the propel also. I just don‘t have them.
You have a great bike and it will never be the biggest area of improvement for you. But I am a stark proponent of aero - always…
Nevertheless, if not every second matters, it makes sense to choose a bike on factors like confidence, joy of riding, and price of course…
They did the propel in the 2017 test. It was around 210w I think.
From people who have ridden the propel and have ridden the new tcr, the new tcr is hands down smoother, corners better and wont beat you up as bad as the propel. I have a propel and its a rough ride and leaves something to be desired on a crit course.
