Zipp Firecrest Clinchers - 303 or 404?
 

OK, I'm about to take the plunge (or rather, have placed an order but can still change my mind).

Has anyone ridden both the 404 and the 303 Firecrest clinchers, and want to give me pros/cons for which to select? Especially interested in the difference in ride feel.


These will be my every day wheels as well as race wheels, since I can't afford two sets. There's a backup bike/wheels for rain.

Bonus points for pictures of bikes with 303 in front and 404 in back.

Thanks!

i have not ridden both of the fc, but had the old style clinchers in the 303/404 combo and now run a pair of 303 fc clinchers.
i too faced this question of the 303/404 vs 303/303 setup and decided the aero difference between the 303 and 404 fc rear was small enough that i preferred the lighter option and got the matched set. does it really make any measurable performance difference? probably not. i seriously doubt you will notice a difference in "ride feel" between the 303fc and 404fc rear, so just go with what you want the most.

In Boulder, I would think 303s.

Lighter than 404s. You prob do a good deal of climbing.
Better in the crosswinds then 404s, so you won't have to go to the backup bike due to wind.

303s are my everyday wheels on one of my bikes. They are great. I'm about 200#s too.

I've got 303 tubulars, not firecrest. Had 404 clinchers, not fc, and just repalaced the 404's with new firecrest 404's.

I'd go with the 404's. Thy're more aero than the 303's and the weight difference is only 100 grams or so.

Only downside is that the 404's are a bit more subject to crosswinds. However, I haven't found it to be a concern in winds below 20-25mph.

The only reason I might favor the 303's is if they would be your only wheel, and you'd have to use them in high wind conditions, or you were buying them for a hill climb race.

That's the reason why they're better in this instance. More versatile. Prob does a lot more climbing in boulder than Jacksonville!

if you're going clincher, go 404, more aero advantage and the weight difference is negligible...I went through the same thing...now when I get tubies I'll go 303 for racing..

so the people saying go 303 would be wrong as far as climbing..and the cross winds aren't that bad, you just won't be descending as fast, at least I'm not...lol. The only way you could justify the 303 in this instance would be if you were going tubular, you'll gain more of an aero advantage with the 404 over the 303 and the weight is near the same with both in clincher because the 303 is so wide, no you also need to make sure the 303 will clear your frame for this very same reason.

Some would argue that the aero difference is negligible too, and may be more negligible than the weight difference, which is probably more negligible than the crosswind stability, lol :)

I have a 303 front and 404 rear. They are not the firecrest model though. Either way, I think you're good. Sometimes I wish I had a 404 front, but I really can't complain about the current set up.

As it is, I have ridden these in high winds and they handled fine in the cross winds. Sure a 30-40mph gust will blow you off line, but your body has more drag than 20mm of rim. They descend plenty fast. I've hit 65 mph and I'm not sure I want to go that fast again. I run a compact crank so it was all coasting.

I would contemplate the ENVE 6.7s for my next purchase.

Here's a pic of my set up.
http://i144.photobucket.com/albums/r...7/IMG_1508.jpg

Cool, thanks, keep the info coming!
Jeffc7, I've got a CR1 these wheels are going on too. :)

zipps data would argue to the contrary...

Please provide link or reference to said data!

I'm presuming the OP is going to want to go downhill as well there in Boulder. (where the high speeds, 50+kph, really accentuate aero adavantages)

The weight savings for the 303 versus 404 is a wopping 84 grams. Conversely, the aero savings for the 404's in a 40k are 11 seconds, over the 303's.

http://www.zipp.com/_media/pdfs/support/aero_edge09.pdf

A 3 ounce weight penality is just not going to cost you much time. Admittedly, the lighter wheel is going to be faster uphill than the more aero wheel, but even then it's by a minute amount, and only if the climb is steep enough to drop the riders speed into the single digits.

Thus on a steep hill climb, the 303's would be the choice. However, on a course that has climbs, and descents, and some flat or rolling terrain, the more aero wheel is going to come out ahead.

A real world example of this is that Tyler Hamilton chose to use 808's to win the US Pro Road Race championship, even though it included multiple climbs of Paris Mountain.

from velonews:
[h=2]"Zipp’s new 303 Firecrest[/h]When Zipp launched the 404 and 808 Firecrest wheels, the industry knew it was only a matter of time before we saw a 303 version. And it didn’t take too long, less than a year in fact.
The new rim is 45 millimeters tall and 28.5mm wide (outside rim width). Zipp has abandoned the tiroidal shape it had previously employed. In fact the 202 is the only carbon wheel left in the Zipp quiver that uses the shape. The 303 version of the Firecrest is very slightly different from the deeper rims. It isn’t simply a smaller 404. And yet, according to Zipp, the 303 performs almost as fast as the 404 and the clincher version gives up nothing to the tubular version.
2012 rear hubs see two small changes that increase rear wheel stiffness by 7 percent. The non drive-side bearing now sits 7.5 millimeters wider (closer to the dropout) and the non drive-side hub flange is canted eight degrees to help with spoke alignment. Word is that builds go more smoothly and the whole wheel structure is improved.
The other new item across the Zipp wheel line is hub and spoke color options. All wheel models are now offered in both silver and black hubs and spokes. The silver is a bit darker than previous years. Zipp calls its pewter-like finish Falcon Grey. Zipp calls the darker option Beyond Black (actually the same finish as SRAM’s Black Red group).
Clinchers weigh 1,498 grams and will run you $2,700. The tubular version saves weight and money at 1,198 grams and $2,300."


the word Almost indicates that its not as fast or "aero" since we already know it's lighter. n===Not saying its not close, but I'm also saying I'm not wrong.

like I said, I'll be getting a set of 303 FC tubies in the future for racing.

I would just go 404. The weight difference is negligible. The more aero 404 will benefit you more on fast downhills. I ride a pair of 404 FC tublars...and I live in a windy area. Once you get used to the wheels...the crosswinds won't be an issue. You can always go 303/404 if winds really concern you.

The Facts:
The weight difference between 303 and 404 is about 50g - that should not be your decision maker.
The 303 FC rear wheel is 8% stiffer than the 404 FC rear wheel. I'd say that is a huge difference. If you're a heavier rider, push taller gears, are very powerful, or spend a lot of time climbing, the stiffer wheel is just going to feel better.

The 303 has a more consistent drag profile in relation to crosswind angle than the 404. While the 404 has a lower average than the 303, it is also much more variable, with significant dip at 15 degrees. The 303 actually has significantly less drag in crosswinds greater than 15 degrees from front.
303:
http://www.zipp.com/_media/images/dy...Drag-Chart.png

404:
http://www.zipp.com/_media/images/dy...drag_chart.gif

This is an important distinction because the center of pressure on these wheels (or most other wheels) is not centered on the steering axis. With the FC wheels, that center is closer but still not perfect. In constant crosswinds, you very quickly adjust, but in gusty winds or extremely high speeds (like a long steep descent where you might be closer to 45+mph), you would experience more rapid fluctuations in that steering torque and thusly require more attention to handling. Since the 303's have a more consistent drag graph, they also have a smaller fluctuation in steering torque as crosswinds vary in direction.


My Experience:
Personally, when I switch from my low profile 7850-C24-CL wheels to my 404 FC-Clincher wheels, the handling is very different in crosswinds. I wouldn't say it's unmanageable, but it definitely gives me pause when starting down a long downhill or when riding in gusty conditions that cause that torque to fluctuate a lot. I am far more willing to attack downhills with the low profile rims primarily because they are slightly more predictable.

I work in a shop that sells a lot of Zipp wheels and we've done demos. Having ridden the 303 FC Clinchers back to back, the 303s definitely have a more predictable feel to them when descending in crosswinds.

So, here it is:
lots of climbing/descents, heavy/powerful rider, or lots of crosswinds, go with the 303.

^ i was about to post both charts...

theres an assumption that just because they are in boulder they are climbing a lot, also power and weight, none of these were listed.
now since the graphs aren't equally drawn out we can only assume that just by looking at where the two wheels come in that the 404 is clearly more aero at roughly 165g of drag vs. the 303s assumed (what looks like) 180ish+g of drag. Crosswinds seems to be a problem for the first couple of weeks of riding and I was able to quickly adjust to the forces against me. Now the real difference where I can feel an advantage is in a paceline or group and being able to maintain speed easier when its my turn in the front.
either way you go, you'll enjoy your wheels.

I think you should have spent some time on demo wheels...

nhluhr,

Good info. Thanks

As full disclosure I ride neither. However, as we ride the same terrain and as you clearly stated that these will be your daily hoops I do have an informed opinion. I would go with the 303s. These are your daily wheels, we get a fair share of gusty weather, we do a lot of descending in those conditions, and I'm guessing you are probably on the lighter side and more subject to getting blown around. Over all, the benefits of the 404s for racing are small enough not to warrant the costs for daily use in our environment. I'd much prefer a bit more consistent stability in winds and on windy descents on our training rides than I value the 10-15sec advantage in a 40K race.

nhluhr,

I'm not seeing where the 303 ever has lower drag than the 404. The pink line (the 303 FC) stays right around 200 grams of drag at all wind angles.

Conversely, the 404 varies between 165, and 80, but it's always below the 303, and at most wind angles significantly below the 303.

I get what you're saying about that consistent profile being an advantage in a crosswind. However, I've never been concerned with crosswinds on the 404's unless it's really blowing.

So I'll stick by my original assessment, the 404's are going to be faster on almost all courses, other than one that is all up.

If your concerned about handling in a crosswind, then that's a reason to go with the 303's.

I think the 2 windtunnel charts support both of those statements.

It's been windy in Boulder the last few days. Seems like that's been the case so far all year.

Aren't you 110 or 115lbs? At that weight, I think the 404s are too much wheel for you. Although they're sexier, I think you'd regret the 58mm profile as your everyday wheel. Can you imagine the swirling winds up at Carter Lake? I know you just bought that sweet TT bike and it would be nice for that application, but I think the disadvantages outweigh the benefit.

My wife weighs the same as you and there's no way she would run the 404s for the same reason. Her experiences and my own with some new 65mm Enves and some old 46mm Reynolds form the basis for my opinion.

I didn't really notice who the OP was when I started into this thread. At 110lbs I think the cross wind issue would be more of a concern than at 200lbs.

The pink line on the 303 chart is the 303 Tubular with a 27mm tire. The red line is the 303 Clincher with a 23mm clincher tire.

Precisely my thoughts. I ride Carter all the time and the thought of descending Pole Hill in swirling winds with high profile is crazy scary at my weight much less at sub 130lbs. Heck, even some of my bladed spoke wheels make riding in those conditions super white knuckle so I imagine that would change my daily ride decisions a far amount if 404s were my daily set. Sometimes those "local realities" are lost on well intentioned fellow cyclists trying to offer advice based on their own local frame of reference.

Get tubulars, not clinchers.

HTH.

OP here - thanks for your thoughts everyone.

I weigh 110, ride in the mountains and up and down the canyons as well as out on the plains. I am very wind-affected -- I get blown around a lot and it scares the crap outta me. We get a LOT of wind here, especially in spring. I lost a couple of places in my last race (Iron Horse road race) due to a slow descent - I was braking b/c I was terrified of being blown off the road - riding on a Kinlin 270 rim. I also race crits, road races and TTs.

I've read everything I can find online, and I understand the weight/aero tradeoffs on paper, I just haven't test ridden either wheel. I did ride my friend's non-firecrest 404s in a TT and found them OK, but it was uphill and not windy, and she doesn't use her 404 front wheel when it's windy, because it blows her around too much. (She's the same size as me.)

I'm surprised to hear the 303 is stiffer. sbxx1985, your local/relevant experience is very helpful.

everyone, and especially nhluhr, if you have more comments, please continue. RIght now I'm leaning towards 303's and considering 404 rear/303 front.