Triathlon - Wheel Aerodynamics vs. Weight

I'm looking to upgrade the wheels on my existing bike and need some clarification and opinions. I always hear that you get the most bang for your buck on the wheels...however I've found that the more aerodynamic models (i.e. Hed 3, Zipp, etc.) weigh almost as much as my existing wheels. However, when I look the other direction and go for pure weight reduction, the aerodynamics goes out the window. Where is the balance, and what will benefit me more?

From what I have read, unless you are doing very steep and long uphills such that your speed drops quite low, the power savings from more aero wheels outweigh (if you will excuse the pun) the power cost of their increased weight compared to lighter but less aero wheels.

`Very steep', 'long' and `quite slow' aren't very precise terms, so for more in-depth explanations, see articles at http://www.analyticcycling.com/

Then there's the added weight savings because after buying your new aero wheels your wallet is a lot lighter too
:D

Yes, on a "less hilly" course, aero generally trumps weight. The thing you also have to take into account it the depth of the rim. If you are a lightweight, a super deep front or a HED 3 will do nothing but throw you around the course. You need to take a bunch of things into account when buying wheels.

And fyi, typically the fastest setup on a tri bike is a rear disc with a HED3 front. You're talking 2200+ grams for that setup. I guess it's like a flywheel effect once you get it going.

Thanks for the help. I'm a bit of a lightweight (about 135lbs) and should do more research for my body type. What about HED Jet's? Would those be better for me to control?

My current bike is a Specialized Transition with the Stock wheels. (Alex A295 - about 1900 grams). Sounds like I might need to think about buying 2 sets of wheels...aero for triathlon and lightweight for road. :)

If you go over to biketechreview.com, the site owner (Kraig Willett) sells some wheel wind tunnel test results. Front and rear wheel results are reported separately, with wheel weights, depths, and aero drag numbers listed for quite a few wheels. There is also a test on discs and wheel covers. It's an open (i.e., widely discussed) secret that an inexpensive CH Aero disc wheel cover ($60 or so at wheelbuilder.com) mounted on a regular rear wheel has about as good aero numbers as a structural disc wheel (e.g., Renn, Zipp, etc.), although there is a weight penalty. The test results run about $15 or so; not very much if you are looking at dropping a thousand or more (maybe a lot more) on 2 pairs of wheels.

unless the course is very hilly, aerodynamics is dramatically more important than weight. Fastest set up is rear disc, and a 3 spoke(HED 3) or a very deep dish front ( such as a Zipp 808).

Thanks for the help. I'm a bit of a lightweight (about 135lbs) and should do more research for my body type. What about HED Jet's? Would those be better for me to control?

My current bike is a Specialized Transition with the Stock wheels. (Alex A295 - about 1900 grams). Sounds like I might need to think about buying 2 sets of wheels...aero for triathlon and lightweight for road. :)

A Jet would be fine, but I'm not sure I would go over the Jet 50 at 135lbs.

Try searching this site. There have been several good rather technical dicussions on this subject. From my own personal experiences and research, don't worry about wheel weight unless it's a very hilly course. Wheel weight makes no practical difference on the flats. In terms of speed, the more aero the better. The problem is the greater the depth (and especially with disc), the less versatile they become. Side winds make handling very difficult.

If you are competitive in terms of performance, the more sets the better. Your thoughts of aero (HED 3s) for tri's and another set for road is a good thought. You don't need to go to absolute lightweight though; something like Zipp 404's are a good compromise.

aerodynamics mean approximately nothing below about 20mph

at 135lbs, you may have some issue holding down a disc in a crosswind

i weigh 120-125lbs and having used both my current zipp 404s and previously borrowed a hed 3 setup, the weight reduction for the zip is fantastic as you rarely find a course that is truely flat

the most bang for your buck is really the 404s or some other lightweight carbon wheel. they can be used anywhere whereas the disc is out with a crosswind. discs are illegal at kona for that very reason.

remember that weight off the rim of your wheels (i.e. carbon rims with tubulars) is worth substantially more than weight off your bike or your rear because it is rotational weight (i.e. the whole inertia thing, that is why 650s get going more easily)

p.s. hehe chrisposito, good call on the wallet

remember that weight off the rim of your wheels (i.e. carbon rims with tubulars) is worth substantially more than weight off your bike or your rear because it is rotational weight (i.e. the whole inertia thing, that is why 650s get going more easily)


Though, just to be the devils advocate. If it is a straighter course, once you get up to speed, wheels with a hevier rim will help you keep your speed. The inertia thing......:rolleyes:

There is an argument for everything. I would say go for a Zipp 404, or another wheel like it. I am partial to the hed stinger 50's (http://hedcycling.com/wheels/stinger50.php)

If you stay at this depth, it is bennificial for anything aero, it CAN be used for training(dont recomend it), and is also the deepest you can go if you want to road race.

Aero trumps weight for time-trialing like triathlons. Not so for road races or criteriums where you have to repeatedly accellerate the wheels. Given that this is a tri forum, you'd presumably be better off with a slightly heavier, but more aero wheelset.

But the point about your weight and being able to keep the wheels stable is valid as well. Aero wheels can be difficult in a cross-wind.

How much time aero wheels will actually save, and whether it matters are different questions altogether.

[QUOTE=lemurhouse]Aero trumps weight for time-trialing like triathlons. Not so for road races or criteriums where you have to repeatedly accellerate the wheels. Given that this is a tri forum, you'd presumably be better off with a slightly heavier, but more aero wheelset. QUOTE]

That's an old myth that is disproven by lots of tests and studies. Aero trumps in almost any condition. Light wheels on roads are only beneficial on steep climbs. Otherwise there's no difference at all.

Light wheels might give you a slight edge in crits but that's more to do with the feel and the ability to mabe react slightly faster than anything else.

<<<<That's an old myth that is disproven by lots of tests and studies. Aero trumps in almost any condition. Light wheels on roads are only beneficial on steep climbs. Otherwise there's no difference at all.>>>>>


Then why do the pros go with light wheels instead of aero wheels in everything except time trials and the track?

If you ride at a reg pace of 25mph or more then go aero otherwise less weight will work better for most of your ride.

<<<<That's an old myth that is disproven by lots of tests and studies. Aero trumps in almost any condition. Light wheels on roads are only beneficial on steep climbs. Otherwise there's no difference at all.>>>>>


Then why do the pros go with light wheels instead of aero wheels in everything except time trials and the track?

If you do a search here, you can find numerous links to studies that show aero is significantly more benenficial than weight in just about all conditions.

If you read or even watch races like the TdF, just about all pro's ride aero wheels in flat legs. They resort to lightweight rims in the mountain stages. If you're talking about other events, many road races have a 25mm depth limit.

Is aero going to help uphill,no.
Is aero going to help if you ride in the bikelanes in traffic,no.
Is aero going to help if you ride like most avg less then 20mph,99% no.
So aero help in some conditions but lighter is helping in ALL conditions.
Look,why not go with a lightweight aero,best of both worlds. Plenty out there but dont forget what your studies must have said,it has to be at least 30mm aero before any benifits might help. Hey i went with Curcults. 28mm aero and 100g lighter then Elites. Bullet proff and and ok in the weight and enought aero to not do much other then look good and if i remember right an aero wheelset will be stiffer?

So aero help in some conditions but lighter is helping in ALL conditions.

The only time light weight wheels help is with climbing. On flats and downhills, wheel weight makes absolutely no differences. There are lots of studies cited here to confirm that.

I do agree with you though; for most riding the combination of light and aero can't be beat.

<<<<That's an old myth that is disproven by lots of tests and studies. Aero trumps in almost any condition. Light wheels on roads are only beneficial on steep climbs. Otherwise there's no difference at all.>>>>>


Then why do the pros go with light wheels instead of aero wheels in everything except time trials and the track?

UCI regs. you can't ride a disc or a trispoke in a mass start event. And if you look at professional racers, more and more are using wheels like Zipp 404's (CSC) and Lightweights(Uhlrich).

Is aero going to help uphill,no.
Is aero going to help if you ride in the bikelanes in traffic,no.
Is aero going to help if you ride like most avg less then 20mph,99% no.
So aero help in some conditions but lighter is helping in ALL conditions.
Look,why not go with a lightweight aero,best of both worlds. Plenty out there but dont forget what your studies must have said,it has to be at least 30mm aero before any benifits might help. Hey i went with Curcults. 28mm aero and 100g lighter then Elites. Bullet proff and and ok in the weight and enought aero to not do much other then look good and if i remember right an aero wheelset will be stiffer?


I haven't seen anything so false in all my days....
First off, Hed proved aero wheels kick in around 13 mph... but lets make it 15 mph

Sooo...

Will aero help you on hills? More than lightweight

Will aero help you in bike lane traffic? hahaha, only as much as lightweight. No one should ride in a bike lans so much they have to consider their race equipment in that decision

Will aero help if you ride slower than 20mph, if you believe Hed (and I believe Zipp has made a similar comment) the two biggest names in aerodynamics? Yes

Does lightweight hurt? No its fun having a light bike, I am picking up some 303s this week as race wheels... but I'm also getting a disc cover for it.



p.s. the balance for me was obviously some on sale 303s, depending on your budget you can get some aero wheels around $700-900 brand new from Peloton, FSA or even Heds if you are patient or find a coupon.

The bigger concerns of aero wheels, moreso than weight, is hub quality, quality control(are you going to need these things trued often?), tire selection, rim depth, rim shape, tubular or clincher...

For what it's worth a Hed Alps is around the most versatile aero wheel out there. It's 50mm deep, so almost anyone can handle it, it comes in at around 1500 grams, Hed is fairly good on Quality Control, The new decals are way better than the old, they have an aluminum braing surface. However, my LBS owner dislies them soo much, he quit carrying them.

Right. I must see,oh maybe none of those most versatile aero wheels out on my rides. Did you expect Hed or Zipp in there unbias tests to have found anything else other then what they found? Also we are talking difference between racing and everyday riding.

I assumed race, since he was talking aerodynamics. And we're triathletes and most of us race. And no they're not unbiased, but I recall Ritchey's Carbons(rebadged Zipps) icking ass in a recent wind tunnel test.

P.S. you were still completely wrong about a lot of what you said in terms of aerodynamics.

You all talk about bias and stuff. Well when wind tunnel tests prove that areo wheels make a huge difference. I am talking about non company wind tunnels. Like MIT for example. I personaly think that areo trumps weight in about 90% of situations. Unless I am around a stop sign/light, I am not under say 25-30km/h, and usually I am cruising at 35-40. So I have yet to find a hill that puts me under 20km/h, and is so long that having light over aero makes it worth it compared to the rest of the ride.

You say light is better. Well try loosing a pound off your body, then you are all good with aero wheels(not all that hard to do). Like I said though, the one hill on the course/ride that you would bennifit from light wheels, doesnt make it worth it because that one hill may be 1-2km long and its on a 100km ride......

Of course for a Tri,aero but for everyday riding, light first.

Why would you want light wheels for everyday riding? Give me a set of 1900g 28/32, bombproof wheels to train on.

I've had Elites and now Curcults both lighter then that and are bullet proof.

Why would you want light wheels for everyday riding? Give me a set of 1900g 28/32, bombproof wheels to train on.

Roger that. Think of how much faster you could get pushing a set of wheels like 10 times as heavy...Better yet...Lets all train on 30lb steel frams:p

Na, I hear ya, I have some bombproof training wheels, that one of them, is like twice as heavy as both of my light wheels(mavic heliums)

I've had Elites and now Curcults both lighter then that and are bullet proof.

Okay, they don't have to be 1900g's but riding most of the 1500 gram low spoke wheels everyday isn't the best idea. Unless you weigh 135lbs.

Now thats way wrong. Dont know what your reading.

Now thats way wrong. Dont know what your(sic) reading.

What's wrong, that it's not the best idea to ride low weight, low spoke count wheels as everyday training wheels?
Again, maybe it's okay for the featherweights, but try weighing 185 and riding Open pros for a year everyday vs Am Classic Sprint 350's(or similar).

When I first got my new road bike, it was all Campy, while my other stuff was Shimano, so I didn't have any training wheels, just the stock ones on the bike. They were a paired spoke 20/24 wheelset. I was going to ride them until I could get another set of training wheels and my Ksyriums' hub switched to Campy. In 1500 miles they broke 3 spokes and flexed all over the place. The roads around here are nice and mostly pothole free. They weren't stressed to any unreasonable level. They were a reasonably light(1600g), low spoke wheel. I would say within the first month, they needed re-trued 4 times. My cousin's Rolf Vectors did a similar thing, as well as my friend's Gipiemme's.

Think whatever you want, but you'll never convince me that a low spoke, sub 1500g wheel(minus a very small few, like the Ksyrium) is a BETTER choice for an everyday high mileage training wheel for anyone over 170lbs.

OK,i wont try.

All good points. I don't think telling telling this 135lb person to lose a pound is really going to help them get faster...unless they are 4' 11". I race on Zipp 404 tubulars and at 185lbs, I still get blown around quite a bit. Of course I live in kansas and the wind freaking blows here. There is one element that is hard to quantify. I don't train in my racing flats for running....but when I strap them on I know I'm going to fly. The fact that I rarely use them also allows the lightwieght feel and "newness" to contribute to the perception that I am going to run fast today. Same with the race wheels. I don't train in them. When I put them on the bike and do the first little spin down the street to make sure they are on correctly...they are lighter, they do roll better, they are stiffer but most of all...I know I am going to ride fast as hell. The mental element is difficult to relate to real speed or aero advantages but it is real. Bottom line is if you slap on some expensive wheel that you researched and studied, your going to be fired up about the new gear and probably extract more out of your effort beyond the obvious advantages of aero and weight savings.

Just a thought...albeit not a very scientific one.