zipp 101 or Zipp 202
 

130 Pound rider
.. and I recently went from williams 19's (1440grams) for climbing
to zipp 101's (1523grams) because I wanted something for the flats..
I was surprised at how much faster they are once they are up to speed
they even surge better in a pack, but, they are definately slower to spin up from a start
I spoke with the Zipp rep at the local TOC and asked him if
the carbon 202's (1378 grams) would hold speed as well as the 101's since they are lighter..
He said that the 202's would hold speed "much" better "at speed" since they are more aero
than the aluminum 101's, and "because" they are lighter.. which makes me want to buy 202's

So the questions is.. At speed, on the flats ( say 22+ mph)

would the heavier 101's hold speed better than the lighter 202's?

I searched around and couldn't find an answer to this question..

thoughts?

Aero trumps light weight for speed on flat ground. While neither of those is very aero in absolute terms, I'd think the 202s would be better than the 101s aerodynamically.

202s by a country mile. They are also 1500 bucks apart.

I'd go with 303's if you want a good all rounder wheelset.

given that neither set is real aero ..
but similiar in aerodynamics, or is the implication that they are not?
and price and material aside
why would the 202's decelerate more slowly if they are lighter?
wouldn't inertia be a greater influence than aerodynamics in this scenario?

FWIW, I saw aero test data somewhere for 202 compared to 303 and they were nearly as good over most yaw angles. Forgot where I saw that...

Go with 404s.

You can tell a noticeable difference between two sets of wheels that are 83g apart and about the same depth?!? I find that very surprising.

This.

You won't go wrong with any of the wheels, but if constant speed flats are the priority, the 404s will be your best bet. Also keep in mind that outside of a lab, the difference in aero benefits between the 202/303/404s is splitting seriously small hairs. If your riding is a good mix of flats and hills, I'd venture a guess that the lower rim weight of the 202 is going to be much more appreciable than the aero of the 404.

the 19's are alot shallower and the 101's have alot more rim wieght and less spokes

and more aero

I was surprized the difference was noticible too.. part of this is probably being so light,

so it makes me wonder if the difference would be noticible with the jump to

202's.. but I have a hard time thinking the $1,500 is worth the leap.

any time I look up Zipp data anywhere... it just keeps coming up marketing speak.

the real question is ...

is the inertia from the extra weight going to make the 101's keep better speed than the

lighter and carbon and "more aero" 202's?

not!...808s or nothing at all...why half-azz it...

Carbon discs all around. You can try sailing it if you get tired in crosswinds.

Friends don't let friends buy Zipp.

go ahead and buy the expensive ones. it's the only way you'll ever know for sure whether it's just a load of marketing BS or not.

Unless someone is paying you decent money to ride for them or you aren't going to miss the $1500 from your budget in any way, there is pretty much no way to logically justify wheels that expensive. No one is going to fault you for buying toys, but trying to pretend there's another reason to buy them is silly.

The beneficial inertia from heavier rims is a misnomer. If it was true, you'd go out with rims that weighed a ton, get them up to speed, and cruise to glory. In the case of bike wheels and the forces acting on them, less mass is always less work than greater mass.

There's a pretty big difference in width that may contribute. HED claims their new wheels are also more aero than their old 23mm rims

I do think there is a design difference and a quality difference between the 19's and the 101's which is what makes
the ride difference noticable.. I was also after the wider rims..
but I DID think that " what spins up faster.. spins down slower" which is why I think (all other things being relatively equal)
the 101's would keep speed better for energy spent.. how does that square with "less mass is less work"?
and the 202's will keep speed better?
that's what the rep is claiming..

The inertia to keep you moving is proportional to your speed. The power to keep you moving is proportional to speed cubed - mostly because of aerodynamic drag.

Aero is WAY more important in keeping you moving fast.

so..
all things being equal.. the lighter the faster..
so in that sense, the zipp guy was right..
the 202 are faster in every catagory..
Dammit Jim..

IMO...202's are single purpose wheels. Go 303 or 404...ooor 303 front and 404 rear.:thumb:

Not according to Zipp. They're essentially the same aerodynamically but the 202s are lighter.

I think it makes a difference the lighter you are... the reason I wanted to stay with lower profile was the wieght
and the influence of crosswinds for a lighter rider.. and of course.. the climibing

I have 101s on one bike and 202s on another (the bikes are very similar.)

I'd love to add something brilliant to this analysis, but I don't notice much difference, except the 202s make a cool engine turbine sound when I apply the brakes.

Placebo is a wonderful thing.

101 look pretty expensive for an aluminum rim.

What do you mean? What does "essentially the same aerodynamically" mean? What does Zipp say?

I looked at the 101 (now 30C) before I bought my last set of wheels, and I believe the 101s are not Zipp's premier Firecrest rim profile. The Zipp site says only the 202,303,404 and 808 use the Firecrest, which is "more aerodynamic than any other rim design." What that means, exactly, is unclear in terms of aero efficiency, but I'd be surprised if Zipp means the 101 and 202 are "essentially the same aerodynamically," but perhaps you have some other insight?

Also, the 202 is wider overall, bead to bead, and 2mm deeper than 101, so if rim shape affects aero performance, well, there's some reason to expect difference between those two.