Interesting read from Road.cc. I live in pan flat south Florida and get 1 week of climbing in Virginia in the summer, this article makes me feel better about going with an alloy/aero wheel as opposed ot paying almost twice for full carbon. Once the daughter graduates college then maybe I'll go full carbon then, but for now it was a good tradeoff

Why riders like you need to go aero, and wheel weight doesn't matter ? and how the wind tunnel proves it | road.cc

"alloy aero" is not going to be as "aero" as carbon aero
I have an alloy "aero" wheel 24mm wide and 31 deep. much better than old box section rims
my carbon aero is 29mm wide 55mm deep, and lighter too


So yes, save up for carbon aero... or make your daughter get a scholarship or a part time job and get yourself better wheels

I have the Bontrager Aura 5 which is alloy wheel but has a non-structural carbon fairing. I can tell a difference when I get up to about 20. Nice compromise.

Have you seen the bikes posted on this site?


Most have the bars as high as the seat and make no attempts to actually get in a more aero position.


Don't be fooled in to thinking they buy ultralight stuff to go faster, they buy it because it's cool and they like high end gear.





Case in point. "world's most aero road bike"....

LOL so true. Especially love the guys with the 17 degree stem slammed but flipped up

There are a number of take aways from that article.

"We've measured a 16% increase in wheel drag between a disc-braked wheelset and a standard wheelset"

"The best tyre we've found is the Continental GP4000S"

"The slower you are, the more important aero is."

"Weight is a secondary issue almost all the time."

Worth noting that their models on weight vs. aerodynamics all consider steady state cases. When cycling we are accelerating all the time. The weight penalty is paid during accelerations, not so much during steady riding. Not saying their models are useless, but it is always important to consider the constraints and assumptions used in a model. Also, just because they found a particular tire to be 'the best' (without talking about widths, pressures, etc.) for their wheels does not necessarily mean that they will be the best for your own wheels.

The article is absolute garbage. Nothing but an advertisement for Swiss Side wheels and Continental tires.

Swiss Side sell alloy wheels with non structural aero carbon farings. Their wheels are heavier than full carbon aero wheels and that is why the play up aero over weight - because their wheels weigh more.

I rest my case.


-Tim-

Have you ever looked at the accelerations usually seen in road cycling? (they're very, very small.)*

*Though it might be more accurate to say they're very, very, very, very small.

And occurring all the time. Not making a statement on 'weight vs. aero,' merely pointing out that their models do not account for accelerations.

But your implication is that by not treating accelerations, they are missing something relevant. At typical accelerations of 0.01g or less and peak accelerations around 0.6g, the energy to accelerate is insignificant in terms of evaluating equipment. (and that doesn't take into account the recovery on deceleration from greater mass.)
As far as I can tell, they also didn't consider the effect of fastener type (allen, flat, phillips) on aero.

I live in the shadow of the Cascades.

Well, the 'aero' was determined experimentally, so the fastener type is included in the drag data they are using. The relevance of what was 'missed' is up to the individual using the model to decide.

Weight! I live in a very hilly terrain and weight is very important.

My standard is that aero is good but not to the point of adding weight to be more aero.

Edit- I also found the tire information to be biased and useless!

We all saw the results of the of the age survey. Whatever it takes to combat the manopause non-aero, non-light gut.

This topic regurgitates itself at least once a week. [MENTION=409489]69chevy[/MENTION] said it best, because it's cool and people like high end stuff.

I've used models that account for acceleration, and investigated keeping a database of moments of inertia for different wheels to improve the estimates of drag and predictions of sprint performance that the models produce. After a medium amount of effort, we stopped bothering.

Why would anyone pick only one?

Sell your house in Florida.
Buy a house in Fort Collins (which is quite flat, but at 5000 feet).

You should be able to pay for your daughter's college, buy the bike... and get better AERO.

There is a reason why Mexico City (even higher elevation) is popular for Hour Record trials.

Why would anyone pick only one?

It's interesting they're testing a Cervelo R5 and not an S5. The R series are the light weight bikes, the S series are the aero (road) ones.

Light weight is more fun to show off than aero ("Here, pick it up").

None of the test bikes was completely red; that would have made a big difference...

Because aero is heavy.

The article saysI find this pretty surprising. It looks like Zipp's 303 Disc is a different rim from their 303. I would expect most of the loss from the rotor to be made up for by a better rim shape.

I have heavy-ish aero wheels for TTing- front and rear 60 mm deep wheels and a rear disc. I'm all for buying free speed whenever possible. My fitter is a purist and does not like compromises.

Every now and then I try to get him to tell me to buy lighter wheels.

He tells me not to. Weight hardly matters as long as my wheels are not ridiculously heavy (which they're not).

However he does tell me he could get me into faster tires. (I resist, because I don't want tubes.)

The best way to test this stuff is going to be road aero testing. Which is coming, it will be the next thing in aero testing.

Of course I have wheels for climbing too. They are only lightish wheels because I prefer an alloy braking surface. No deep profile on my climbing wheels because I don't want to get hit by the crazy canyon crosswinds while on a high speed descent.

And of course if I was doing mass start races, I'd consider a set of wheels for that. Maybe full carbon but maybe not. There's an argument to be made for race wheels that aren't too expensive to replace, at least until you get to pretty advanced levels.

Hmm. Maybe the real answer is that there are pros and cons to different wheel types? And those pros and cons apply differently to each of us, based on whether we're riding recreationally vs racing, our weight, terrain, budget, and personal preferences? And that therefore it makes little difference to second guess or judge the other guys wheel choices? Cause maybe his decisions were made based on factors that are not immediately evident to you, looking at his situation from the outside?