Looking for guidance. Should I get 404 or 808 Zipp front and back? Will they make a difference vs stock wheels? Middle of pack rider, expect to finish around 3 hrs for bike ride
What are you riding now?
I have used race day wheels and had a good experience. I used a Zipp disk and
a 606 front. Like them, not enough to purchase.
Faster, yes. How much? Debatable on number of seconds/minutes.
Use the wheels that you have and save $150.
A “606” front is a 404.
For $150 you could get a wheel cover for your existing wheel and be able to use it in future races. It will make you faster and makes your bike look way cooler 
Like you I am a ~3hr 70.3 bike rider. I think that my cover makes me go faster but it is hard to quantify as weather impacts your speed so much.
With a cover on the back wheel you could look at buying a deep dish front wheel in the future.
Looking for guidance. Should I get 404 or 808 Zipp front and back? Will they make a difference vs stock wheels? Middle of pack rider, expect to finish around 3 hrs for bike ride
If getting deep section wheels for triathlon, those wheels would work fine. I got wheels last year and went for Swiss side Hadron 625 front and Hadron 800+ rear (62.5mm front and 85mm rear rims). They’re nice, they’re fast, they have alloy brake tracks which I wanted (I do ride in bad weather and on mountains, plus I’m over 80kg - brakes matter).
Whatever you go for, don’t allow yourself imagine you’ll get hugely faster. You might gain a little but it will be a little.
If I was to buy mine again, I think I’d go for a 625 rear as well. The reason is simple. What I have is perfect for the tri bike but I’d use them more often on my road bike if they were both medium depth. The extra depth doesn’t gain you a whole lot on the tri bike and if I wanted more I could just go for a disk wheelcover which works just as well over a box, shallow, medium or deep rim - but the shallower options are lighter! I still might get a disk wheelcover in which case the 85mm rims will be somewhat redundant.
I was asking this same question last year before my ironamn. My cosch said save the money. You will only save about 5-10 mins. If you are going to buy a set then thats different. I just picked up a pair of mavics for 500. If you think its worth it then go for it but i agree with the coach and would rather throw money into my own pair.
You will only save about 5-10 mins.
I doubt this is true, but if I would save that amount of time I’d spend the $150 in a heartbeat.
A set of wheels will probably make you around 0.5 MPH faster. If that is important, go for it. You will probably get around 3 to 4 minute savings in the race. But, if it were me (and I made this same decision), I would save the rental money and just buy a set eventually.
Sorry 1-5mins.
To answer your explicit question exactly the way you phrased it … yes, they will make a difference vs stock wheels.
A slightly more useful question is; “are they worth the money”. And the answer to that will depend on how much time matters to you in this race, and how much money matters to you in general.
The best question would be; “what is the best way to get faster with the amount of money that I could buy a set of Zipps for”. The answer depends on what your existing setup is. If you are already sorted for, in this order - position, clothing, helmet, and probably even tires - then the answer might be “buy the wheels”. But it probably isn’t. The right answer to this two thousand dollar question is probably postion, clothing, helmet, tires and then maybe wheel cover.
Tell us more about yourself and your setup. Lots of ways to get more faster than the amount of faster that faster wheels will make you, er, faster. If that even makes sense.
Edit: are you asking about whether to rent race wheels? Is that what “race day wheels” means? If so, go for it. Your race photos will be sooo much better.
Of course there is the one big thing about wheels that we should not forget…they looks nice!
I’m not kidding, it’s as much or more of a reason half of us buy them as anything else.
Tyres cost 5% of the outlay and may have a similar impact depending where you’re starting from, but they don’t do much to make the bike look better.
There’s a reason you see bikes with $2k wheels and Gatorskin tyres… it’s not REALLY all about speed!
My fastest times across the board have come on 808’s from RDW. If you want to see your absolute best time and have the cash do it. Assuming you can get a pair for $1500 that’s a good 10 rentals. No brainer for me.
Thanks for comments. Struggle to pay $1500 for race wheels as i use wahoo kickr so would truly be for just race day. Do one major race a year and could justify 150 once a year, and not sure value there for oly distance races
Thinking i try them. 404 and 808 same price, so why not 808? Right?
One downside is you won’t have a chance to practice with them. If you’re not used to deep wheels the 404 would probably be a safer choice.
Personally I don’t see the point of spending $150 to save a few minutes if it’s not going to make the difference of a possible podium spot but it’s your money. For a full distance even at middle of the pack seeing that finish line 4 minutes sooner is priceless.
As far as them being the same price “so why not 808”…
My 2 cents would be that if you go ahead with renting the wheels, just stick to the 404 up front. Don’t get the front 808. When you buy your wheels it gives you a chance to ride them during training and therefore get used to them in winds and other weather conditions. By renting them you miss that opportunity. You may find the 808 uncomfortable in crosswinds, especially when you haven’t practices with them. If that were to happen, you would potentially lose any aero benefit from the front 808. The 404 will give you decent benefit with better control.
I would definitely go for a set of Zipp 808’s for an Ironman 70.3!!!
For a normal 70.3 half-iron race, I’d look at the course (hilly, technical, windy, etc…?) and find wheels that complimented the course.
That’s just me though.
Looking for guidance. Should I get 404 or 808 Zipp front and back? Will they make a difference vs stock wheels? Middle of pack rider, expect to finish around 3 hrs for bike ride
No don’t waste your money use the wheels you have. Heck, you could probably go faster on your wheels with the right tires and a latex tube.
I would definitely go for a set of Zipp 808’s for an Ironman 70.3!!!
For a normal 70.3 half-iron race, I’d look at the course (hilly, technical, windy, etc…?) and find wheels that complimented the course.
That’s just me though.
Honest question. Do we know what tubes Race Day wheels uses? I doubt it is latex but I don’t know. Also they aren’t using the fastest tires out there. Going with rental wheels could very wheel be slower than using your own wheels with the right tires and tubes.
Thanks for comments. Struggle to pay $1500 for race wheels as i use wahoo kickr so would truly be for just race day. Do one major race a year and could justify 150 once a year, and not sure value there for oly distance races
Thinking i try them. 404 and 808 same price, so why not 808? Right?
I’ve never had issues handling 808’s. Usually you get them 1-2 days pre-race so you have time to try them out. Make sure you have a spare tube with an 80mm stem just in case (luckily I’ve never needed it).
Disc, now that’s another story. IMNC 2016 + disc rental was cataclysmic.