Aero vs light wheels

[User Name]

The difference between a shallow rim 32 spoke wheel and a good aero wheelset may amount to 20W at 30ish mph. You can get that from tyres if you are using the "wrong" ones at the moment. If some one has more accurate data then please add.

I'm the first guy around town to make this point to my cronies but, in "most situations", the difference won't be that much. However, I suppose it depends how 'wrong' the slow tyres are compared to the fast tyres.

On this Bike Tech Review test, some very slow tyres, such as Conti Ultra Sport, are around 7 to 9w slower than the fastest "race-only" clinchers (with latex tubes), but, like.... who uses Ultra Sports any more?!?! Eeew! Perhaps only the newest of newbies.

http://www.biketechreview.com/tires_old ... g_rev9.pdf

[teufelhunden222]

lol, atm I am 260lbs (down from 300 in december) I hammer the bejezus out of my bike. I can maintain 24mph without a problem at all on the flats(with spinergy xaero-lites)(Read as insanely un-aero). Given my shoulder size and relative cross section. I will take any aero benefit I can get. Also no one is mentioning the increase in stiffness of deep section wheels. If a wheel is stiffer it transfers more POWAH!!!! As much as I love my spinergy's for thier comfyness and relatively light weight(1500 grams clincher) The PBO spokes are huge, and the rear wheel does experience a good amount of wrap up (enough to make noise in the 350 watt range). So I am fairly certain I would gain a decent amount of speed everywhere going to a 404 or a ENVE wheel. However I am not everyone, so take with a grain of.....well crack

[bm0p700f]

The info I gave came froma Tour test. The worst performing tyre tested (4 season, some hutchinson tubless efforts and few others) gave power comsumption of about 55W at a high road speed where as the likes of the GP4000S gave a comsumption in the order of around 32W or something like that. Which goes to show which test is closer to reality? I do not know as I have not done emperical testing my self and the only kind of test that means anything.

[WMW]

are around 7 to 9w slower than the fastest "race-only" clinchers (with latex tubes)

Per wheel!

[User Name]

Yes, per wheel, but that's comparing the worst tyres to the absolute fastest and lightest.
Who still hacks around of Schwalbe Stelvios or the old Conti GP 4000? No one, I reckon.

About the worst tyres I see the odd cool riding on their wet day bikes are GP Four Seasons or Gatorskins

[istigatrice]

I had a sudden moment today...

I think we can all agree on the fact that a lighter wheelset (or any body) will accelerate faster... yeah?

now, by definition, acceleration is the rate at which velocity changes (note velocity is NOT speed)

as velocity is direction dependent, our rotating wheel is constantly changing direction, which means a change in velocity. Therefore acceleration is present. (Picture a car turning a corner at a constant speed of 60kmph, this is not a constant velocity, thus acceleration is present)

Thus, we are always accelerating...

Have I missed something here?

Also,

According to newton III (or newton I, depending on how you want to interpret it) an object moving at a constant velocity will continue to move at a constant velocity, unless a net force is applied...

When we are going up hill, due to gravity, the more weight we have, the higher the Fg is (extra weight), meaning to have a zero Fnet (to stay moving at a constant velocity), we need to apply more force (pedal harder). Wouldn't this mean that even if we are riding at a constant velocity, weight still matters? (Fair friction is another force too btw)

Please critique

EDIT: had no idea this thread was this old...

[Lewis]

I just want a set of Aero Clinchers purely because they sound so nice when traveling at speed - that noise they make is addictive!!

For all other times my Mavic Ksyrium Elites do the job. Strong, light, tough for horrible UK roads and big potholes, stiff for climbs etc.

I think unless you are racing it makes no difference. Just ride your bike more and you'll get faster on what you have. I rinsed loads of fat boys on full aero bikes on the last ride I went on, on my modest sub £1.5k bike with non aero wheels.

[wingguy]

Thus, we are always accelerating...

Have I missed something here?

Yes. The net acceleration of the wheel is 0.

[sigismond0]

You're incorrect, the wheels are not accelerating unless they're increasing or decreasing in rotational velocity. The direction of velocity can change at will, acceleration is only in effect when the magnitude changes. When thinking of wheels or other things like this, you really ought to be thinking in terms of angular velocity--the rotations per minute, or the like. As long as that number remains constant, the wheel is not accelerating.

[Krackor]

as velocity is direction dependent, our rotating wheel is constantly changing direction, which means a change in velocity. Therefore acceleration is present. (Picture a car turning a corner at a constant speed of 60kmph, this is not a constant velocity, thus acceleration is present)

Thus, we are always accelerating...

Due to the wheel's rotation, each segment of the rim is constantly accelerating (linear acceleration) towards the center of the wheel. The net force applied to the rim segment comes from the spoke tension and the material tension of the rim itself (adjoining segments of the rim are bonded together, so one piece of the rim doesn't go flying off without the rest of the rim... until the rim breaks). However, the net (linear) acceleration of the rim as a whole is zero (when riding along at constant speed), so it doesn't take any extra force/power to keep a heavier wheel spinning.

[airwise]

I've never done a constant 30mph on a normal road ride so why do people rely on such meaningless figures?

[fdegrove]

Hi,

Thus, we are always accelerating...

Have I missed something here?

In a way yes. The same way we're continuously decelerating just the same.

No further comment,

[roadiescum]

I have been going back and forth on this and I keep getting different opinions.

Plan A: Custom build with Pacenti SL23 rims, Chris King hubs and CX ray spokes. Soild build but average aero (although the wide rims are supposed to help).

Plan B: 40 to 50 mm carbon clincher factory wheels (looking at the Rolf Prima Aeres 4 or ENVE 3.4 or 45s, I have been using the Rolf Vector Pros for 8 years with no problems).

I live in Florida so moslty flat with lots of wind.

What sayeth the group? Is the aero really the best thing since sliced bread?

[Calnago]

Sliced bread was way better.

But, since you took the time to post,
1) you will always get different opinions
2) If a topic always gets different opinions, then that means implies there's no real clear answer, and that means you need to look within yourself for what you feel is right. Many people don't. So take all the opinions, including what you get here, and make up your own mind.
3) You live in Florida, flat and lots of wind. How windy, really? And how much do you value how your bike looks. The 40-50mm carbon hoops do look pretty cool on most bikes, but there are bikes where a low profile classic wheel looks just as good, and rides better in my opinion. What bike are these going on?
4) All of the options you mention are fine choices and I doubt you will go wrong with any of them. If I thought you were way off base on any of those choices I'd say so. If you had a lot of big gnarly descents I might suggest rethinking the carbon clincher thing. But it's flat in Florida, so don't worry about it. Have fun deciding.

However, at the end of the day, sliced bread will still be way ahead of aero bicycle wheels in the history of great achievements.

[jcumpstay]

I have both a set of Pacenti SL23's on Alchemy ELF/ORC 11spd hubs and also a set of Enve 3.4's on The same hubs but in 10sp. Both are amazing, however with a 25mm Veloflex open tubular, the Pacenti's are my most chosen riding wheel. I don't often ride in windy conditions, but when there is a decent cross wind the Pacenti's shine. My Pick would be the Pacenti build.