coolcamaro12

I have always seen articles/videos on new road bikes with people touting "The frame is light but not as aerodynamic". Aerodynamics seems to be a huge part of a good bike from these various sources, but is it really that big of a deal as long as the bike frame is fairly smooth and streamlined?

Brian Ratliff

Wrong question. Aerodynamics unquestionably matters to some extent. The right question is: is it worth paying for the advantage that an aerodynamic frame gives me.

Strictly in terms of performance tradeoffs, when you make a frame aerodynamic, you either make it less stiff to pedaling forces, or you make it heavier. I have an aerodynamic track frame that, frame alone, weighs more than some people's entire road bike.

Cost wise, because there is an additional performance factor to design to (besides weight and stiffness), a good aero frame will always cost more than the equivalent non-aero frame. Is it "worth it"? Depends on what you do with your bike and what your cash account looks like. Myself, I have two road bikes; none of them are "aero" framesets. The aforementioned track bike... because I have goals involving national competition on the track, it's aero.

coolcamaro12

Thank you, Great answer

floridamtb

+1 And from everything I've read it seems like an aero frame might shave a few tenths of a second etc off a 20 mile time trial. So like Brian said, is it worth it?

njkayaker

There is also the issue of diminishing returns.

The absolute performance gain is small but the cost of that gain is high.

If you are racing (and are competitive (that is, if you have a chance to place)), then the small advantage might be worth the high cost (noting that the people you are competing against are likely buying the more expensive bike).

For "normal" riders, the gain might not be worth it at all.

Aerodynamic benefits also are greater for higher speeds (if one isn't riding very fast, the performance gain isn't likely to be worth it).

rpenmanparker 

Everything you said was right, but you left out the greater discomfort due to less vertical compliance. Another common trade off of "aero" frames.

caloso

+1

In my observations, it seems many riders would gain more aerodynamic benefit by bending their elbows more.

sced

For 99%+ people it's merely a fashion thing. Some of them look kool and that's all there is to it.

njkayaker

In my club, many people obsess about bicycle weight but nearly-always ride on the hoods. What those people should do is cut-off the drops!

The "problem" is that they justify it by the performance gain, which is kind of a falsehood (and the bicycle industry is complicit).

This is part of what causes many people think they need an expensive bicycle and that bicycling is "expensive".

What most people need is a good bicycle and to ride more.

johnny99

Either your math is way off or the Specialized wind tunnel guys are lying through their teeth. Specialized is claiming fairly large speed improvements, at least for professional racers. For your ordinary club cyclist, the gains not significant.

njkayaker

(I suspect that floridamtb is exaggerating a bit.)

What claims exactly?

What do you mean by "large"?

Often, the claims made by manufacturers is under optimistic and limited cases. In real life, the "large improvements" might not pan out.

We'd really need to see the actual claims to evaluate them.

Are we talking about "professional racers" or "ordinary club cyclists"?

gsa103

It really depends on your riding and conditions. The average rider doesn't go fast enough (25+ mph) to significantly benefit from an aero frame on a regular basis.

An average rider is likely to notice aero improvements when they're riding into a 10-15 mph headwind. So if your riding regularly in windy conditions, I can see an aero frame being a nice improvement. Probably mainly applies to the Midwest & Florida people.

OldTryGuy

Don't tell Marcel that the aero Propel Advanced SL he rode was heavier, non compliant and just not the best for riding long road racing distances compared to a regular road frame and the chances of being around at the end to compete for a podium place were not too good.

RChung

Then "everything you've read" isn't "everything that's been written." At serious racing speeds in zero wind a really good aero frame can save more than a minute in a 20 mile TT over an already not shabby aero frame. If you're slower, or if there's a crosswind, you can save more than that.

Whether a minute (or more) in 20 miles is worth it depends on you, your goals, and your bank balance.

PaulRivers

You're seriously suggesting that the default assumption wouldn't be that a marketing department is lying? Wait, I don't mean lying, I mean exaggerating, confusing, purposefully misleading, etc...

It always goes something like this:

Specialized: We've reshape the top tube to provide up to 300% more aero top tube!
Reality:
- "up to" means not in most conditions, in average conditions it's 25%
- The top tube makes 0.01% difference in overall aerodynamics
- In order to do this they made the bike heavier and less stiff, reducing actual power in a different minor way
- They 20 test runs and only chose the # from the best one
- It actually provides worst resistance in a crosswind
- Etc

Edit: I do believe that they can create a more aero bike frame, but that usually seems to be "if you're in a time trial", it increase it by a # that's only significant for racing, and only applies to bikes that also change your riding position (aka aero bars). It's still a minor increase compared to everything else that's going on.

I don't mean it's 100% bunk, I mean a regular bike frame is already fairly aerodynamic - when you talk about the improvements to the frame vs a regular frame it seems like they're very small, and still minor compared to the aero effects of your body position.

Jiggle

They are silly.

JohnDThompson 

Not to mention that the advantage of an aerodynamic frame only becomes at all significant at high speeds. For the speeds most of us ride at, the advantage is negligible.

caloso

Even when he's on the tops, Eddy is more aero than you.



Even when he's on the hoods, Eddy is more aero than you.

CALE262

This...unless you're racing and looking for seconds or 10ths of seconds.

hueyhoolihan

agree... that's all it is for just about everybody.

hueyhoolihan

next time i get passed by Marcel Kittel on a Propel Advanced SL, i'll just reel him in and tell him what you said, just 'cause you said not to.

justkeepedaling

The amount of misinformation in this thread is simply staggering.

hueyhoolihan

IMO, there's not one inaccurate or misleading statement in this thread, so far, well ^^^ one.

RChung

Every once in a while a thread actually destroys knowledge, creates ignorance, and leaves the world worse off than if it had never existed. This is one of those threads.

Brian Ratliff

1+

People: listen to this guy when talking about aero stuff. He's done a lot of work with it. A minute saved over a 20 mile TT (at race pace) is something around 2% faster, or 5-6% energy saved, which is about what I would expect (maybe on the high side, but within eyeball reason).