Aero Wheels 101

Some people will pay a thousand plus on wheels and pull it out only on races.  I guess it's because accidents happen and you would hate to trash your expensive wheels during a training ride and be out that money.  I wanted a wheelset that I could ride 100% of the time train and race).  If I trash them, the wallet won't hurt as bad.  I went with Flo 60\90 setup (Dec 2012).  I ride them all the time except on the trainer because I'm too lazy to change the tire.  I plan to get a disc jacket from Wheelbuilder for my races this year.

The bolded is what I would recommend if cost is an issue.  I rode a FLO 90 with a cover for my rear training wheel last year, and with that setup I was confident enough to take on just about any setup.

Leegoocrap lied, you'll want to ride on Conti GP4000s tires!

In general you'll probably want to look for a 60mm or so depth for the front wheel.  Seems to be the best all around compromise for weather (wind) conditions.  Yes riding with a disc cover on the back helps stabilize the bike up front, think stabilizer tail fin on a plane.  Hard to beat FLO wheels these days. I patiently watched eBay and picked up a used 60/90 set for $644 total vs $900 new.

Current rims are indeed going wider, major benefit is you can run a 22-23mm tire up front and a 23-25 on the rear and have a more comfortable ride.  More air volume, less psi and same or lower rolling resistance.  You can run a 23 tire on a narrow rim but aerodynamics will suffer. Issue with running a more narrow rim (20mm wide) is that using narrow tires or ideal aerodynamics, except for a very few models, results in higher rolling resistance.  You really want the ideal wheel+tire aerodynamics and tire/tube rolling resistance (+durability). 

The current wheel tech starting a few years back  is for U shaped (more or less) rims.  Much older rims were V shaped, then went to a toroidal shape and so forth. I once read that riding with crosswinds that a new U style 60-66mm wheel is like riding an older gen 40-50mm wheel, same for 90 vs older 60-66. Here's an example of older rim shapes:

Current FLO shapes:

Actually I think the Specialized Turbo Cottons are the current "bees knees" in racing.

Yep.  This is exactly why I only use race wheels for races.  I've trashed 5 rims or hubs during training and my wallet thanks me for not having to replace something expensive during the times where maximum speed does not matter.

The cover will make you faster but the gains will be pretty small.  I ran some tests through www.bestbikesplit.com (awesome site if you've never used it) last year on that exact scenario and over a half ironman distance it was at most 20-30 seconds (vs a deep rear wheel like a flo 90) and that was with some pretty windy conditions.

It looks way cooler though and that makes it all worth it!  

 Edit to add that I'm not saying 20-30 seconds isn't necessarily worth it.  Make a few changes that net you 20-30 seconds each and suddenly you are into minutes.  

If you're handy there's a DIY disc cover thread here.  I bought some 0.060 ABS online and made my own for my old wheels.  Looking at other options now for my FLO90 and found this on eBay for some thin Kydex which is a little harder to work with but is only 0.028 thick & also found some ABS in 0.040".

Most wheels come with a solid quality hub with steel bearing and are all I need, put the money for ceramic bearing elsewhere (e.g aero skewers, helmet, etc.)

Deeper front wheels do catch more wind with cross-winds, i.e., slide loading, which effects the handling.  If your heavier, or very fast, than may not be as big of an issue.  majority don't need the hassle and go with mid depth (60's).

I agree with Chris(leegoocrap): FLO90 with a disc cover on a training wheel.  90% of the time I see this set up it's a clear indicator of performance over cost spending; very popular at the FOP too. 

3mar, you should be careful and make sure you are not including any comparison test that includes using a Butyl tube, also watch out for clincher (C) vs tubulars (T).  There are only 4 GP4000s listings on the main sheet (2-20c and 2-23c, one of which is with Butyl) and you show 5 tires.  I thought he also tested a 25c GP4000s but don't see it listed.

Another way of looking at the data, just sort the tires in lowest to highest Crr and look at/plot only those from 25W and less per/2-tires at 30kph (why go higher for racing) and then you'll see that most are wider tires.  If I counted correctly, there are 20 clinchers (removing tubs and out of production tires) of which 3 are less than 22mm in measured width and 6 are less than 23mm in measured width.

I thought it would have been a good data point to include a column in the SS to denote is a tire had built in puncture belt.  He thought about adding it but in the end said he'd leave that decision to the user as some tires are stated clearly and others leave you guessing if it does or not.  If you knew one offered better protection at the same Crr maybe you'd go with one over the over, e.g. Conti Supersonic 20c vs. GP4000s 23c.  In this example the GP4000 is less aero due to the width but again that's up to the user to decide. 

I thinking about switching my race day tires to the Attack/Force combo. Should offer better aero on the front at the same Crr and the fatty in the back doesn't matter for aero but offers muchless Crr.

Sorry to the OP taking over this thread with tire discussion!

I'm thinking about getting the disc cover from WB.  Will this crack pipe work?  http://www.amazon.com/Topeak-Pressure-Presta-Valve-Adapter/dp/B00GKH49GI/ref=sr_1_1?ie=UTF8&qid=1425928807&sr=8-1&keywords=silca+adapter  The Silca adapter on their site is $32.