What determines if you use a Zipp 404 Firecrest vs 808 Firecrest front? Taking in to account the following:
Money is not a factorAverage between 24-27mphSprint to Half I.M. DistancesAlways being in the aero positionNot worried about side wind handling of the bike with the 808I was looking to find out when one should use the front 808 over the 404. I was told 2 conflicting reasons. First being, you need to be riding @ 30mph for the front 808 to be to your advantage. Then I was told that the aero dynamics of the wheel was designed to make a difference at 15mph and to use the 808. ?
For what ever reason Zipp doesn’t seem to have a chart with both the 404FC and the 808FC on it. But looking at the individual charts it looks like they are pretty much tied until about 7-10 degrees yaw, then the 808 is faster. Pretty much means you can’t go wrong with the 808Fc in all conditions.
The business about 30 mph is horse pucky. And as for aerodynamics. There are numerous charts here that would indicate that at almost wind angle the 808 is faster.
For what ever reason Zipp doesn’t seem to have a chart with both the 404FC and the 808FC on it. But looking at the individual charts it looks like they are pretty much tied until about 7-10 degrees yaw, then the 808 is faster. Pretty much means you can’t go wrong with the 808Fc in all conditions.
This Blog here has compared the graphs and begs to differ, he reckons the 404 is actually the better wheel across the board and is better suited for changing conditions than the 808 and this is why Zipp has avoided a comparison.
This graph shows a mixture of data from HED and Zipp and plots the FC 404 v the FC 808 directly against each other - what is clear is that the better wheel is probably the FC 404! Why? Because the wheels have almost identical drag down to 10 deg Yaw, and the FC 808 only manages a slight drag decrease to 15 deg yaw, and then the drag on the FC 808 rises significantly after 15 yaw because the wheel is stalling and starting to cause massive turbulence at that point. So the (pretty much) age old rule of deeper=better may not necessarily hold in Firecrest country, the FC 404 should perform almost the same as the 808, and once it gets windy, it performs significantly better than the FC 808. It will also probably cost a lot less than a FC 808 as well.
the only things ever that would move you from 808 to 404 is:
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worried about wind gusts giving you handling problems
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it is a hillclimb race, and a really steep one at that. like > 12% and never comes back down =)
What determines if you use a Zipp 404 Firecrest vs 808 Firecrest front? Taking in to account the following:
Money is not a factorAverage between 24-27mphSprint to Half I.M. DistancesAlways being in the aero positionNot worried about side wind handling of the bike with the 808I was looking to find out when one should use the front 808 over the 404. I was told 2 conflicting reasons. First being, you need to be riding @ 30mph for the front 808 to be to your advantage. Then I was told that the aero dynamics of the wheel was designed to make a difference at 15mph and to use the 808. ?
that dude is wrong, I’m putting both into google docs to prove it, I will post a chart later today, gotta go train first.
For what ever reason Zipp doesn’t seem to have a chart with both the 404FC and the 808FC on it. But looking at the individual charts it looks like they are pretty much tied until about 7-10 degrees yaw, then the 808 is faster. Pretty much means you can’t go wrong with the 808Fc in all conditions.
This Blog here has compared the graphs and begs to differ, he reckons the 404 is actually the better wheel across the board and is better suited for changing conditions than the 808 and this is why Zipp has avoided a comparison.
This graph shows a mixture of data from HED and Zipp and plots the FC 404 v the FC 808 directly against each other - what is clear is that the better wheel is probably the FC 404! Why? Because the wheels have almost identical drag down to 10 deg Yaw, and the FC 808 only manages a slight drag decrease to 15 deg yaw, and then the drag on the FC 808 rises significantly after 15 yaw because the wheel is stalling and starting to cause massive turbulence at that point. So the (pretty much) age old rule of deeper=better may not necessarily hold in Firecrest country, the FC 404 should perform almost the same as the 808, and once it gets windy, it performs significantly better than the FC 808. It will also probably cost a lot less than a FC 808 as well.
here, got it done in time:
https://docs.google.com/spreadsheet/ccc?key=0Agu_Y5SLfSFKdHF0VXBsd04wMXVQeXFoWnJxS2doYUE
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the german tests show even bigger differences than what zipp states. the charts do not count for tire sensitivity which makes the 808 even better.
Also depends on what width tire you want to run. Both FC rims were optimized for a 21mm tire, but if you want to use a 23mm, the 808 has less of an aero penalty than the 404.
Zipp’s website shows that a 808 pair is 16s faster than a 404 pair over 40km. Since we are only talking about a front wheel, and taking into consideration that the front wheel has a bigger impact on aerodynamics than the rear wheel, we are talking around ~10s difference between a 808 vs 404 front. BIg frickin deal. Get in the pool, take a few lessons and save way more time in your overall racing. If you hate swimming, fine, put some practice into transitions and again you can probably save more time than that.
10 seconds would have made my wife the fastest (amateur) TTer in the state this year instead of 2nd.
or again, as usual, there is no single aerodynamic gimmick that makes any sense. But when you make 10 choices to save 10 seconds each. that is a lot of seconds =)
buying an 808 instead of a 404 does not prevent you from also practicing your transitions and swimming.
Zipp’s website shows that a 808 pair is 16s faster than a 404 pair over 40km. Since we are only talking about a front wheel, and taking into consideration that the front wheel has a bigger impact on aerodynamics than the rear wheel, we are talking around ~10s difference between a 808 vs 404 front. BIg frickin deal. Get in the pool, take a few lessons and save way more time in your overall racing. If you hate swimming, fine, put some practice into transitions and again you can probably save more time than that.
Jack Mott yesterday
“you can quit worrying about frame weight. for example, up Alpe Duez, a 400gram lighter frame, which is about the max difference you are going to find, you are 15 seconds faster out of ~45 minutes (ignoring any aerodynamic differences)”
Jack Mott today
"10 seconds would have made my wife the fastest (amateur) TTer in the state this year instead of 2nd.
or again, as usual, there is no single aerodynamic gimmick that makes any sense. But when you make 10 choices to save 10 seconds each. that is a lot of seconds =)"
Why do you hate Newton so much?
Agreed on all accounts. TT is a different venture than long-course triathlon though. 10 s in an Olympic distance tri or 40-50 s in an Ironman normally doesn’t make any difference. For the record, I purchased a set of 404 FC at a price that was too good to pass up. My first choice would have been 808s, but I couldn’t justify the price difference for the savings of a few seconds when I have much bigger issues to address with my sh$%y running.
I called zipp and asked a while back. They gave me the numbers for a standard Firecrest 808 front vs. a non-dimpled 404 front or even dimpled. From there mouth 15-20 seconds over a 40k tt. Even at half ironman and ironman distance I opted to see the 808 FC front that I never actually raced on and keep my trusty stable 404 (non-fc) . I will say the FC 808 was alot more stable than the old 808 but for me I like having one wheel regardless of the wind speed. 808 FC was not as stable as a 404 standard. If I had all the money maybe and then really maybe 15-20 seconds 40k or up to a minute in a half ironman just is not worth it.
So the census is the 808 FC is better in all aspects other then a steep hill climb?
So the census is the 808 FC is better in all aspects other then a steep hill climb?
and strong crosswind handling. though if what jordan has said is true (I think he said the new 808 feels like the old 404) then I can’ imagine too many people would have trouble with it.
The one guy i know who has ridden both says he can notice the 808FC getting pushed around more. I’m not sure at what point he would choose to not ride it but its there.
Still if you are buying a wheel for racing go with the option that makes you fastest 95% of the time and just ride a trianing wheel the other time.