That is a great article. I read it some time ago, but it is still great. Thanks for bringing it back...

---

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Good call. More fuel for the fire that aero trumps light unless climbing is long and steep.

Good stuff, thanks. Should be required reading for anyone wondering which bike to ride in a race such as LP or Wis (or Canada for that matter).

On a related note, I've been wondering if there are any big-name races on the international tri circuit where a road bike is the better choice. In my opinion (probably not very well-informed), the only candidate is IM France in Nice, but that's probably more because of the twisty descents. Maybe if the Athens Olymipc course held a non-drafting event?

Any thoughts?

-C

---

------------------------------------------------------------
Any run that doesn't include pooping in someone's front yard is a win.

Light and aero - Carbon Soloist or the new Guru Maestro look like perfect choices for hillly, non-drafting events.

you don't understand ANYTHING that I have laid out so far....

all other things being equal (weight), a more aerodynamic part will be faster.

all other things being equal (aerodynamics), a lighter part will be faster.

and if one measurement is realatively close and the other signicicantly different, than the part that is best at both is the best choice...

FOR EXAMPLE:

if there are two forks, one is aerodynamic but realatively heavy. the other is withing 95% of the others aerodynamics, but weights 250g less. The lighter part is the better choice.

g

---

greg
www.wattagetraining.com

Don't rule out the QR Lucero. My large frame weighs just over 17lbs complete with cages, pedals, etc. and HED 3/Zipp Disc wheels.

Dean Wilson
www.anaerobiczone.com

---

Dean Wilson
http://www.anaerobiczone.com
Bicycle Protection Indoors & Out

the analysis doesnt account for a difference in power output when crouched over. On a UCI legal bike(shallow seat tube angle) the rider will be in an abnormally scrunched position. On a tri bike the steep angle puts your body into a position similar to a road bike, making this more legitimate. Also, no aero v. weight comparisons account for acceleration after turns, traffic, other real world situations.

not necessarily - heavier wheels, on the right course (ZERO climbing), would be faster than lighter wheels. But I digress...

No, heavier, MORE AERO wheels on a flat course would be faster than lighter wheels. But only if they were proportionally more aero than the increased moment of inertia. Wheels that are 1% more aero and 100% heavier will NOT be faster.

---

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Please please not the heavier wheels may be faster than lighter wheels debate again.



Styrrell

I know, I realized it was trouble as I was typing it....

no, heavier wheels of equal aerodynamics will have a higher moment of intertia, therefore resisting deceleration and requiring less power to maintain the same speed. They will, however, require more power to raise the speed.

Uh-oh, not this again...

I know heavier wheels have a higher moment of inertia. That is why I said they must be more aero than the proportional increase in moment of inertia. (Once you figure out what that relative factor is, which would require lab testing for each set of wheels compared.)

Higher moment of inertia is NOT a good thing. Please, please, please do some research before you reply with something stating otherwise.

---

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Doesn't mean a thing unless everything is deamed equal.....so that skinny little twurp on that mega aero/light road bike is going to be way faster than i will ever be no matter what bike i ride...unless it is motor powered...lol...[i'm 6'1, 200lbs] but man look out when i start going down hill...lol....

Everyone still discussing "aero" vs "weight" ....blah, blah....

This is what I got out of the article. :-)

worth seeing again- I agree. Good material:

http://web.archive.org/...tiondirectory=techno

Old news. I remember posting that article on ST a few years ago.

Another good old article that says aero beats light every time:

http://home.hia.no/~stephens/aero.htm

I must confess, I didn't take many physics courses in school, and the ones I did take were a long time ago. But something about heavier wheels "requiring less power to maintain the same speed" just doesn't sound right. I seem to recall that it takes exactly the same energy to maintain a constant speed no matter what the weight. The only difference is when accelerating or decelerating, where the heavier object takes more energy . Can someone tell me if my memory is still OK or is age taking it's toll?

Greg.

I think that Newton guy had the same opinion as you. Crazy kids and their fancy bikes... Power = Drag Force x speed .... hey your right, no rotating mass or moment of inertia in that equation. Then again I heard that Newton was a good TT'r but a lousy in the mountain stages.

I'm just a chem. eng. so I only had to take statics (got out of dynamics. :-) ) so you mechs feel free to jump in and correct me.



If you're talking linear motion.......kinetic engery = 0.5 X mass X (velocity)^2 so KE is a function of velocity and mass. (i.e. same mass and velocity = same KE. different mass and same velocity = different KE)

If you're talking rotational energy....KE = 0.5 X Moment of Inertia X angular velocity Were the moment of inertia = mass X radius^2 so rotational KE is also a function of velocity and mass. (i.e. same weight and angular velocity = same KE. Different mass and same velocity = different KE)



I don't know about this either. I think people are talking about adding mass to the rim to create a flywheel. Is this better?????? I didn't take dynamics. :-)

Doesn't Force = m X a ? Larry Newtons second law?

I thought that was Fig Newton's third law. Either way if a = 0 then look out for falling apples when you a sitting under a tree considering that life is a drag (ie. the only force on a flat course at a constant speed).... As long as speed and elevation stay the same there is no change in energy so don't sweat the mass thing dude.

Thanks! You saved me lots of $$$$. I was just going to drop some cash on an SRM. It's pretty flat here so I guess it would read 0 all the time. :-)

Don't make me use calculus...You do not what me to use calculus.

Zero drag usually means riding in a vacuum. I don't think I have the VO2 Max for that.