Okay I hear you guys on here say that aero trumps weight everytime except uphill TTs. Heres my question I hope you guys can make the right decision on wheels for a race this weekend.

I have a flat 50 mile road race in florida on saturday. Its a 14 mile loop no hills with the exception of a gradual up hill finish. it has maybe 6 turns total. I am 5'7" 149 lbs. I have normally race the American Classic 420 aeros which are pushing 1530 grams but have the oppurtunity to race some zipp 404 aluminum/carbon clinchers. The bike weight with the: 420 aeros weight 16lbs 08 ozs
zipp 404s weight 16lbs 13 ozs

the amount of aero advantage of the: zipp 404 58mm depth
420 aeros 34mm depth

Is the zipps the right choice or should I be leaning to the faster spin up of the 420s. I am on the fence. Thanx for any data or insight you might be able to get me.

go with the 404s. the weight difference will save maybe one second TOTAL in acceleration advantage. the 404 is a proven aero advantage.

So even with the weight and spin up difference your saying their is a significant aeroadvantage to the 404s over the 420s that will more than offset the weight and spinup? Do you think the spin up difference is much different?

i think the spin up difference would save almost nothing. hence, my guesstimation of 1 second savings total.

The maths say that about 80% of the effort on a bike is spent pushing air out of the way, and deep section aero wheels are timesavers. But what us cyclists actually know is that in racing you are mostly riding in someone's slipstream, ie. in the dirty air from the guys in front, and do not encounter a smooth air flow unless you are on/off the front. And there are things called sidewinds.

All said, for a short flat race I would go 404's. And 50 miles ... is that a serious race?

Because our Cat4 road race is combined with the Cat 5. its a omnium weekend. Whereas in 2 weeks the Cat 4 road race will be 72 miles. Been racing cat 4 for about 5 weeks and I'm halfway already to my cat 3 upgrade. I cant wait to get to the 80-100 mile races


so you also agree that 404s are a way better option than the 420s for a flat road race.

I've never bought the inertia theory's. At flat road race and criterium speeds aerodynamics will help you accelerate much more than those 200+/- grams weight savings.

Some seem to forget that weight isn't the only factor in accelerations. Aerodynamics also play a huge role in how easy you will gain speed after a turn as you still need to beat the wind.

Awesome. Thanx for all the responses. I am getting ready to purchase zipp 303 firecrest carbon tubulars soon, but sounds like these 404 aluminum/carbon clinchers will work for now.

404's all the way.

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Cervélo S2 2012 Red
Great minds think alike... sadly, so do the mediocre ones.

Absolutely 404 will CRUSH the 420s on a course like this. Hell, you could get Lightweight Obermeyers and the 404s would crush them here

How you attach your race number will matter more than having aero wheels.

Even still, aero wheels will make you faster.

Sorry, but I call bullsh!t on that one

It must be the anti placebo effect I take these out on the road and they feel sluggish. Is it just my mind knowing there heavier and bulkier. Maybe i should put a different tire on there. right now there is continental gp4000 that are 2 years old the guy says. they are in good shape. Maybe i should put some vittoria diamonte 220tpi or come open corso cx.

the getting going seems harder. But it might be my mind