It's like that here. Our Sat. group ride is 38 miles. The hill at mile 16 shatters the group. If you're not up front with the domestic pro and cat 1,2 leg breakers you're not going to catch up. The best you can do is create a chase group and race for 5th.

Yeah...we've got a couple of current and former domestic pros (one of whom rode the Giro not long ago), former Olympians, national champions of various stripes, etc. on our local group rides as well. You're right about that making for great training.

The thing is...I don't pick (nor run my best) equipment for group rides though. I save that for the guys I actually race against, who are none of those things I mention above...just average schmucks like me.

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http://bikeblather.blogspot.com/

Your n=1 aside, getting dropped on a climb almost always means you end up chasing solo, thus burning more energy than those aero wheels will save you. I know you probably said in jest but for one who pontificates about precision...

Burning more energy in reference to what? You seemed to have missed that even with 2-3lbs less weight (assuming I could get wheels that much lighter) I STILL would have been dropped (with equal energy expenditure) And to top it off, I'd have been much less likely to get back on afterwards (with equal energy expenditure...alls I can do is alls I can do ;-)

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http://bikeblather.blogspot.com/

Energy spent chasing back on. Big difference between going over a summit :20 versus :30 back in how much that equates to chasing. Like I said, maybe that worked for your n=1 example on an easy descent, but not in most cases.

Coincidentally, I did exactly the same comparison for myself yesterday. I also had a chat with Zipp support about the data. Here's what I gathered:

- The 303 graph does not have a vertical scale, but it is actually in grams, like the 404 graph.
- The horizontal scale on the 303 graph is not linear, but both it and the 404 graph have data points at the same yaw angles - 0°, 5°, 10°, 12.5°,15°,17.5° and 20°. Both are more like Excel line charts, rather than true graphs.
- The 404 FC testing was carried out using 23mm tyres and the same test conditions as the 303 FC test.
- The 404 FC clinchers and tubulars have similar aero performance.
- The claimed weight difference between the 303FC CC and 404 FC CC wheelsets is 59g.

My personal conclusion was that if, as Zipp claims, the majority of real-world riding is represented by the 10° yaw angle conditions, the weight difference is so low, the prices are roughly the same and since there are no huge hills in my area, I would be better served by the 404s.

Great info! Thanks.

My only take on this is that if one insists on running 23C or greater tires, then they're probably better off on the FC303s.

Uh Oh ;-)

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Styrrell

What's your glitch?

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http://bikeblather.blogspot.com/

See the following thread on Weight Weenies:

http://weightweenies.starbike.com/....php?f=3&t=97169

And in particular this graph submitted by Zipp.



So, as stated before, you gain 70 gms in weight, but you save 50 gms drag in aero.

  
Interesting...the comment I made at the time was based on Rappstars speculations only (that's all we had)...note the use of the term "probably". Glad to see there's finally data to show "what's what".

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http://bikeblather.blogspot.com/

Sorry for bringing up an old thread, but figured my question didn't need a thread of its own.

I am contemplating the 303 vs 404 myself. Ride mostly in flat terrain in the midwest but will be doing a few rides/races in CO. ~100g difference in weight between the two, however the 404 has slightly better aero (seems like drag is around ~100g difference at the largest delta). I am leaning towards the 404 as it will be the better all around wheel. However, would I be crazy to consider a 303/404 mix?

I don't think that's crazy at all. But, I "guess" that the 404 will be a tad stiffer because of the shorter spokes. That may make some difference on descents with switchbacks. So I'd choose the 404s.

So really, I'm probably not gaining too much benefit with the 303 front then? Drop a little weight (~50g) but lose some aero. I'm not worried about the handling aspect of the 404s. So maybe the 404s are the best option.

Hi!, and how about if I am short? 114 lbs and 5’3 weight? I have to doubt of buying a front 303 or 404 .. Rear sure to be 404. I am not sure if I can handle a front 404 (wind, etc) My bike is a Cannondale Slice RS..
Should be better a front 303 for me?

See if you can demo the wheel. Even at my lightest cycling weight 5'9" 143 pounds I had no problem with a 90 mm front wheel. But people have different levels of skill and confidences. I think you'd be fine with a 404 up front, but try to demo it first

A deeper rear wheel makes for better handling. Physics. If you were going to run an 808 or disc rear, I think the 404 would be a safer bet. But if you're going to go with a 404 rear, it opens up the question a bit.

Plenty of macho guys on here who swear they run a 90mm front with no problem, and yet go to a windy race and see who is actually in aero for the windy bits...not saying it doesn't happen, but I am saying this is the internet.

A 303/404 setup for someone your size is a very valid option. It might be slightly slower under some conditions, but it might be a lot better under some conditions as well. Take into consideration your average speed, the courses and conditions you race (and might race), and Plan B. We're not dealing with the theoretical optimum here, but the real world. Something that you're confident and comfortable on, that is still darn fast, is not a bad thing.

I have 303 and 404 but tubulars. I can't really tell the difference in handling...unless its super windy. I'm 5'8" and 140lbs.

I would go with the deepest wheels you're comfortable with. Even if you climb...I would take the 404 over the 303. The weight difference isn't that much.

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Cervelo S2/Zipp 404

As would I. I always felt like I was flexing my 303s quite a bit, but our team sprinter had the 404s and said he loved them because they were nice and stiff.

Anecdotal, but that was our experience.

The 303 should be stiffer. Its slightly wider and has more spokes than the 404.

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Cervelo S2/Zipp 404

Rims are more flexible?

Like I said, the 303s noticeably flexed and I'm not particularly big or powerful. Granted, this was the 2001-2002 version, so there could have been a layup difference. I've ridden Cane Creek Chronos with a 58mm rim and they were far stiffer, but different wheel and different lace up and all.

Wheel stiffness is a complicated thing.
Take two identical wheels, make the rim on one wheel stiffer, and it may end up seeming to flex more.

this is a good read:
http://www.slowtwitch.com/..._Stiffness_3449.html

In general I don't think any of the Zipps or Heds have any stiffness problems that are substantitive, and I am a big powerful rider (for short time durations), but your frame plays into the equation as well.

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Here's my take on wheel depth coming from a 5'8" 132lb guy.

I can't ride a H3 once the weather station starts reporting wind gusts over 35mph. I prefer to go straight for a 50 or 60mm wheel at that point anyways so I skip the 80-90mms.

When it comes to road racing I find myself dabbing the breaks as I approach 50mph IF I am on the 50mm 7850 Dura-Ace wheels or 404s. I just do not like the way the bike moves around under me at those speeds so I am actually faster with a slower set of wheels because I can let it hang a lot more. Getting over the climb with the front group doesn't mean anything if you get dropped on the descent.

303's seem good enough for the pros during the spring classics. Doubt there is any stiffness/flexing issues. Plus if you want to run a wider tire I think you could do that on the 303 as it is wider than the 404.

Hi Aaron,

Andreas Klier (formerly a Cervelo TestTeam pro) agrees with you. I was recommending the 404s even on the mountain stages, but he explained to me that for him, in the autobus, the critical moments aren't on the flats or uphills (the autobus keeps reasonable tempo so the group can stay together), it's the descents. There are often a lot of sprinters in this group, who are typically heavier and have good bike handling skills, so they try to bomb the down hills as fast as possible to make up time when they can.

Andreas told me, coming around a switchback, there can sometimes be gusts. On a deeper wheel, he might have to touch the brakes to avoid going off the edge of the road - and lose the wheel in front. Then he would feel tempted to "ease up" in the next corners, possibly falling off the back and facing a looong ride to the finish alone.

So he chose the 202s in these stages, not for climbing, but for handling on the descents.

It was surprising to me at the time, but it made sense when he explained it.

Cheers,

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Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)