Triathlon - What is most important in a great Tri bike?

Obviously apart from the engine and the training of the engine.

Which two factors are most important to a great Tri bike?

Other: Helmet. You triathlon guys blow huge amounts of money on equpiment, yet don't get a good aero helmet. I will never understand why I see people riding sprint or Oly distance tri legs on TV with regular helmets on.

Fit is going to be the most important. if it doesn't fit you won't be aero, and you won't put out the most power you can. As for which aero componets make the most difference, aerobars are first because they facilitate an aero position, and the rider is the biggest drag componet by far. Next would be aero wheels, then aero frame shaping.

all Tri bikes will have steep geometry, aero bars, and be labeled a tri bike.

After that, being fit for it by a good fitter (not always your LBS) and a good wheelset will see the most improvements.

If it was top 3, it would be Fit, Wheels, Helmet. after that, its moot IMO

Other: Helmet. You triathlon guys blow huge amounts of money on equpiment, yet don't get a good aero helmet. I will never understand why I see people riding sprint or Oly distance tri legs on TV with regular helmets on.

It seems that you don't understand many things... The testing that Lance did in the wind tunnel suggested that the helmet would provide a 1.75 mi (or about six minutes) advantage over 100 miles (I agree, pretty significant over that distance). In a sprint however, this advantage drops to about 20 seconds for the fastest people. Also, the aero advantage is negated if the rider looks down (even slightly) so in practice, the time savings is even less.

Most of the televised Olympic events are draft legal (i.e. ITU) and many of the competitors ride road bikes. There isn't much need for an aero helmet in these races.

IMO, the helmet/tri-bike relationship is analgous to the parsley on the plate next to your porterhouse. A well made, aero frame is going to be 1-2 mph faster than a road bike...over 100 mi that will be a savings of 4-7 miles (or 10-19 min) and it isn't affected by dropping your head. Even in a sprint it could be nearly two minutes.

http://www.pezcyclingnews.com/default.asp?pg=fullstory&id=3574

Man, the guy at MIT must be idiots then, according to you. Or do you know more than them? And do you also know more about it than Liberty Seguros? I doubt it.


From the article, and data from the MIT boys:

2. Equipment
A common misconception about equipment is that of the order of aerodynamic importance for aero-gear. Most think that the frame matters the most, wheels next, and helmet last. Some even think that the components come before the helmet. In reality, a well designed aero-helmet will save you more time (power) than anything else. The drag difference between a vented road helmet and an aero-helmet is 2-4 times larger than the difference between a good aero-wheelset and a 32-spoked wheelset.

http://www.pezcyclingnews.com/default.asp?pg=fullstory&id=3574

Man, the guy at MIT must be idiots then, according to you. Or do you know more than them? And do you also know more about it than Liberty Seguros? I doubt it.


From the article, and data from the MIT boys:

2. Equipment
A common misconception about equipment is that of the order of aerodynamic importance for aero-gear. Most think that the frame matters the most, wheels next, and helmet last. Some even think that the components come before the helmet. In reality, a well designed aero-helmet will save you more time (power) than anything else. The drag difference between a vented road helmet and an aero-helmet is 2-4 times larger than the difference between a good aero-wheelset and a 32-spoked wheelset.

There are plenty of other studies out there to the contrary. The quote you listed doesn't give any real data either.

I can tell you from experience that my avarage speed in a 40K time trial is nearly 2 mph faster on my Cervelo P2 SL than on my Specialized Allez Pro Roadie...both fitted by the same guy. There is no way that a helmet is going to get me that.

Duke, that's an interesting article. I noticed a definite paradigm shift among top Ironman contenders so far as their helmet selection. This year, almost all of the top contenders wore aero helmets. A few years ago, this wasn't the case. My next upgrade will be an aero helmet and I'll be getting the HED wheels sometime later.

Oh really? So your bike is the object providing the most air resistance to your forward motion?

I always thought it was the body that was far larger in frontal surface area than the bike...maybe you're literally rail thin then...?

Also, are you saying that the MIT boys are wrong? If so, can you provide evidence to the contrary? Did you actually read the entire article, from the link? Not just the part I provided. I highly doubt that they would publish this without a lot of experimentation and data to back it up. Unless you can provide information that says that aero wheels/frame help more than a helmet, given the same position/aero bars, your claim does not hold up.

Also, your improvement on two bikes is very subjective. Your Cervelo P2 SL was more than likely purchased at a far greater level of fitness, and the conditions were more than likely not exactly the same. A wind tunnel provides very repeatable testing procedures. Your personal experiences do not.

Similarly, I called my uncle, who happens to be an MIT astronautical engineering graduate (#2 in his class) about what to get my cousin for Christmas. The conversation drifted into my upcoming season, and I asked him about the effects a TT helmet would have. He rides a good amount, too. Off the top of his head he said it would help significantly more than a wheel upgrade.

. Off the top of his head he said it would help significantly more than a wheel upgrade.

I don't have the data on hand, but as I recall performance data showed helmet at about .8% and wheel at about .5%.
Aero tuck, ala superman position, gives most bang for buck.

My guess is the most important are:
1- rider positioning and fit on bike
2- slippery clothing
3- wheels
4- handlebars
5- helmet
6- frame
7- fork
8- bike geometry

Obviously, the helmet doesn't matter if you're sitting straight up on the bike. My point was that, on the same frame geometry, handlebars, and setup in general, you will gain the most from an aero helmet out of any other equipment upgrade.

And its probably the cheapest performance boost that many triathletes neglect.

Instead they blow it on aero cranks or some other BS.

There are plenty of other studies out there to the contrary. The quote you listed doesn't give any real data either.

I can tell you from experience that my avarage speed in a 40K time trial is nearly 2 mph faster on my Cervelo P2 SL than on my Specialized Allez Pro Roadie...both fitted by the same guy. There is no way that a helmet is going to get me that.

Does the Specialized have aero bars on it? Do you use the same wheels? Is the specialized's position set up for TT's with aerobars, or set up for road racing.

Assuming the same wheels, areobars on both, the Cervelo would only be that much faster if the geometry of the bike was allowing you to get in a more aero position. Just the aerodynamics of the bike itself (i.e foiled shaped tubes, seat tube wrapped around the rear wheel etc.) would not make you 2mph faster.

It seems that geometry is not getting enough attention. Part of a great tri bike is getting off of it & running. If your fit is not good, & use burn out your legs, you will have no legs left to run with.

I think I am being misunderstood...most likely my fault. To sum up...all I am really trying to say is that even though there is some wind tunnel evidence about aero helmets, it is not as impressive in the real world as most cyclists cannot maintain the proper body position long enough to get all of the advantages. I've read more than once in Triathlon or Inside Tri that if a rider's head slumps forward just a bit, it negates the aero advantage of the helmet. The MIT guys (and Liberty Seguros) are not the only ones to do wind tunnel tests and the results that Discovery/Allied Aerospace came up with had some contradictions.

Also DoK completely ignored my comments re: why people don't wear aero helmets in sprints and olys...

I agree that an aero helmet helps...more than wheels? maybe. Whatever. Happy Holidays!

Which brings up another interesting question. Do you ever wear an aero helmet when not sprinting?

I think the Cervelo web site has data on the most recent Ironman at Kona. It seems that the Cervelo tri bikes are becoming more popular.

These are my favorite things about a great tri bike:

Great deraileur
Decent saddle
aeroshifters
clipless pedals over toe cages

Not much more could ruin a bike ride than having your chain jump off while reaching for the standard handlebar shifters, hitting a pothole that knocks you off the crappy saddle & not being able to escape the toe cages. :)

Seriously, I think the fit of the bike is foremost, but followed by my list above.

I'm with you cjbruin on the aero helmet being only moderately important; and DoK, correct me if I'm wrong, but don't wind tunnels only blow in one direction? Last I heard, every breeze is not a head wind, and I'f I was riding 60 miles in a crosswind, I certainly wouldn't want some 18" long head fairing pulling on my neck for 2.5 hours...I would also feel stupid wearing one if I wasn't a world class triathlete, which I'm not. Hey, taping your mouth closed would probably make your face more aero, but at what cost? Comfort is the most important factor in cycling, by far. other than personal fitness of course, but thats a given.

It was all so interesting to me that I went ahead and bought one...if H20chick is reading this, she is probably laughing her a$$ off.

I bought the Rudy Project Syton and now I'm trying to think about the best way to give it a real world test. Opinions are welcome.

The biggest issue is trying to get similar conditions...this may be near impossible when you think about all of the factors.

I'm with you cjbruin on the aero helmet being only moderately important; and DoK, correct me if I'm wrong, but don't wind tunnels only blow in one direction? Last I heard, every breeze is not a head wind, and I'f I was riding 60 miles in a crosswind, I certainly wouldn't want some 18" long head fairing pulling on my neck for 2.5 hours...I would also feel stupid wearing one if I wasn't a world class triathlete, which I'm not. Hey, taping your mouth closed would probably make your face more aero, but at what cost? Comfort is the most important factor in cycling, by far. other than personal fitness of course, but thats a given.

The wind tunnel results that I have seen include data from up to 30 degrees off of head-on.

Exactly, now if only wind tunnel data worked for the other 300 degrees of possible wind direction...

Do you have any really long, straight hills near you?

If so, on the next calm day, you could hit the top of the hill at 10mph or so, get into a good, repeatable aero position and just cruise down the hill w/o pedaling. Chech your speed at the bottom and then repeat with the other helmet.

The only variable would be your positioning, and, with a little diligence (tuck, head angle, crank/foot position, etc.), this should be fairly negligible.

Steve

Oh yeah, and be sure to post your results.