Aero vs light wheels

Everything about building wheels, glueing tubs, etc.
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HammerTime2
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by HammerTime2

Interesting. Now consider the following scenario, which perhaps led me astray.

Case A) Assume 4 riders all with the same power output and aero losses when riding by themselves. Have them ride 2 across and 2 deep, so the same scenario as tested by the magazine, but with each lead rider having someone behind.

Case B) Same as case A, except there are only 2 riders, with one in front of the other.

I thought that case A should be faster than case B. And a case with 3 across, each with a lead and follower should be even faster. Is that correct? Perhaps the side by side riders need to be close enough together to get a favorable effect? I thought that, assuming there is a fixed number of riders behind each lead rider, the more riders across, the faster, because it was making the air go around (outside) the riders, in addition to over the top. But maybe that's not always (or ever?) true? On the other hand, as I suggested above, perhaps more side by side riders helps as long as there is at least one row of riders behind?

Anyhow, I'm pretty damn sure, that except when there is a very large net tailwind relative to the bicycle speed, that a rider A can ride faster if there is an equally capable rider B drafting rider A, than if rider A rides by him(her)self, even if rider A is in front the whole time. In other words, even though a wheelsucker gets more advantage than the rider whose wheel is being sucked, a rider can go faster with a capable rider sucking his(her) wheel than (s)he can ride by him(her)self.

by Weenie


bm0p700f
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by bm0p700f

Well that is an odd result.

HillRPete
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by HillRPete

HammerTime2 wrote:I thought that case A should be faster than case B. And a case with 3 across, each with a lead and follower should be even faster. Is that correct? Perhaps the side by side riders need to be close enough together to get a favorable effect?

That's not how I understood it. More riders next to each other create more drag because they are influencing each others air displacement. Here's a crude sketch of how I'm imagining it. The lines would be the flow of displaced air.

Code: Select all

single     double
 file       file

  ^        ^    ^
/ O \    / O \/ O \   Riders
| O |    | O .. O |   Riders
 ...      ........
  .        ......     Low pressure zone
             ..

Zoro
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Joined: Wed Oct 30, 2013 12:52 am

by Zoro

Last time TT Zipp 900 rear, Trispoke front Vittoria Cronos CS 21mm tyres. Continued...
Image

Plan for this Sat is same bike with 55mm 500g lighter wheels. Any predictions?

Image

Rider will have different speed suit vs. skin suit. Rider is same size and weight, but 4 months have gone by.

Here is why I'm excited about this.
At 60k plus rider is coasting as he is on 52X14 gear and pedaling churns the air - a lot. He coasts. So other than material in the suit, same rider, same weight, different wheels. Most of the power variables are eliminated (unless he decides to pedal a bunch).
But as half the ride in time is uphill, can he gain 1kph in speed going up? Fitness differences almost ruin the test going up, but if he can gain +1kph on ~30kph going uphill, and loses less than 2kph going above 60kph going down - we have a winner.

ultyguy
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by ultyguy

To go completely off track for a second to the single-file, double-file discussion above. First off, for sure, having a rider behind you makes you faster relative to riding on your own because of the low pressure behind you not sucking you backwards. Secondly, let's say you have a break of 6 people, in my hood, everyone goes double file and circulates through, but for my physiology, I've always perferred single file, but I think the data would back it up too. I'd love to see some power meter testing of the theory though. Anyone know where there might be some?

NealH
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by NealH

A constant rotating front (double file) will make up for any aero loss to pure single file riding due to the human effort duty cycle. Its a fresh legs approach. There are always fresh legs taking the lead so the net effect is like a single file line with the puller always on fresh legs (which will never be the case).

ultyguy
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by ultyguy

Yeah, I do understand the freshness, but somehow for me I feel better going harder for 2-3 min then easier for 6-8. I'd just be interested to see some power profiles comparing.

alexaqui
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by alexaqui

Hi all. I recently put together a C59 and restored a C50, both with Campagnolo. I am currently looking at buying a do-it-all fast training/race wheel for both road and some triathlon. Over on slow twitch, no one seems to care about weight, so there is a Flo love-fest. I am not convinced. I have a pair of ~2009 vintage Zipp 404 tubulars that have little use and the hubs are shot, so I want to skip Zipp this time around. I am very intrigued by the new Campagnolo Bora 35, and even the Bora One, both of which come in around 1250 and 1325 grams respectively. The price point on these through planet cyclery is quite attractive as well.

On the other side of the equation are the "new tech" wheels, Enve 3.4, 6.7 as well as the Hed Stingers. The Heds seem to have hub issues. I cannot go custom on the Enve wheels as I can get a very good discount from the shop where I bought my C59 on the standard enve build (DT 240). These newer wheels are touted as being more stable and ultimately more aerodynamic. The only issue is that they all weigh more (either tubular or clincher). Am I being silly for seriously considering the Campy options over the Enve options? Both the C59 and C50 ride so wonderfully even with crazy stiff "old tech" wheels, I don't see the necessarily feel I need to go wider. The Flo wheels seem like boat anchors; not sure I want to do any road racing with those.

After repairing one frame, buying another, and buying 2 sets of 11 speed gear, funding is a concern. Any suggestions?

spdntrxi
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by spdntrxi

I'd go tech personally.. nothing wrong with Enve's with DT240 build...others are also "aero" Aeolus, Zipp FC

bombertodd
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by bombertodd

I'd make a list of the wheels that have the tech (wide and aero profile). Cross off the wheels not in your budget. Then choose the lightest wheels left on the list.


I think if you tried the Flo's in a blind test you would like them.


Another option, that I would do, is to relace your 404 tubs to some nice hubs (T11's or Chris Kings would be nice) and buy/build a cheap set of clinchers to train on.

alexaqui
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by alexaqui

The Enve's are at the very max of my budget, so could probably swing it. Will they fit a standard road bike frames (e.g., C50, C59)? The front wheel is pretty wide. It also seems that for 100 grams, I get the convenience of a carbon clincher, so probably will go that route.

As for the 404, I will most likely go that route. Considering a CK hub or a Tune hub.

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dj97223
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by dj97223

I chose and just glued up a pair of Bora One 35's with the ultra dark labels. Man, they look really good in person, the hubs are Campag and the new braking surface promises to be quite good - but I have not had a chance to ride them.

If you are in the US, you can buy the 35's through Ribble and get them for hundreds less than the Enve or the HED Stingers. There is no aero data on the 35's, but your Colnagos with Campag will look so much better with the 35's that you will certainly be inspired to ride faster. :lol:
“If you save your breath I feel a man like you can manage it. And if you don't manage it, you'll die. Only slowly, very slowly, old friend.”

alexaqui
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Joined: Fri Dec 13, 2013 6:42 pm

by alexaqui

no need to quote the above

Please let me know what your experience is. Planet Cyclery also has them super cheap in stock. Right now it is going to be the Bora 35 or the Enve 6.7. I am planning on rebuilding my 404s, so I have the mid-depth covered. To be honest, I don't care so much about looks as I do about performance! I have 3 road bikes right now and race on an S-works SL4, which I am desperately trying to sell. LOL. I am racing on 15 year old 404s :)

Zoro
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by Zoro

alexaqui wrote:After repairing one frame, buying another, and buying 2 sets of 11 speed gear, funding is a concern. Any suggestions?
See my post above with picture. Those 55mm came to 1110g. Coach sold his Reynolds RZRs and bought a pair and raced on them this weekend.

They do need a wider tyre. You should not be "big".
http://mercurycycling.com/collections/carbon-1

HillRPete
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by HillRPete

The Secret Pro weighs in on Zipp vs Lightweight
http://cyclingtips.com.au/2014/04/the-secret-pro-4/

(As pointed out by pastronef in the pro cycling thread)

by Weenie


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