Take fit over weight - but if the 2 are comparable on fit and handling - then take the lighter one.

A lightweight bike will help you in 2 main areas: acceleration (think high school physics F=ma -- to travel at a constant velocity on a flat surface, the only force required is to counter the slowdown friction in your bike and from the road), and climbing (you need to overcome the mg force downward to go up and the slowdown friction from the road and your bike)

Since in a triathlon, alll we do is time trial and there is not much need for fast accelerations (ok, so you want to accelerate out of corners, but you probably don't do crazy full effort out of the saddle to close the gap in front of you as quickly as possible) so the only place weight would help would be climbing....

So unless you live and race in a very hilly area, I would take aerodynamics over weight and I also agree with RV...

So that’s my problem!!!! I need to think more about High School Physics when I am on a long hard ride and need to accelerate. Physics…physics…physics. Thanks Catwood I will try that on my next ride. :D
- T

Don't forget your Newtonian physics:

A body in motion tends to stay in motion.

And for the couch taters

A body at rest tends to stay at rest.

Good information from everyone.

TBRAVO, they told me that you want the additional weight so that you have more inertia. "You might have to expend a little more energy getting up to speed, but the bike will want to stay there...provided you are aero."

Merlin, you answered a big question for me. First, I had my mind made up on a Cervelo P3 Carbon...then I started contemplating the Litespeed Blade. Now I'm considering the Griffen. However, I picked up a Griffen frame this weekend and it didn't feel as light as...say a Kuota...or something similiar. But you are saying that you are faster on the Griffen with the right set up?

It is tough making up my mind and regardless of the choice, it is a lot of money. I want to make the right choice. As far as fit goes, isn't it possible to get the perfect fit on any of these bikes? Or are certain frames more adapted to certain bodies? And how do you know which one? (I'm sure this last question is going to open pandoras box but I am interested in reading some points of view from those of you who have gone through a few of these purchases)

Ideally, I want a durable bike that will last me for many years, regardless of the abuse I put it through. I'm getting a little scared about a carbon frame because they seem so fragile. What happens if I have a wreck? That is why I'm leaning on the Litespeed or Griffen.

Jeremy

OK I have to throw in a few words for carbon. I ride an Aegis road bike that probably has between two owners seen well over 20,000 miles. And I wouldn't trade it for anything. And to add to that I have a Schwinn mountain bike that has a carbon frame and if i haven't been able to damage that frame through some of the dumb ass things I've done over the years, you don;t have anything to worry about from a road bike. The technology is improving so quickly that a lot of the old concerns about carbon are going away. The manufacturers are constantly moving to better grades of carbon, such as for the Madone SSL (I think) that Lance and the climbers used in the Tour this year. And the manufacturing processes are improving so that they can manipulate the layers and weave direction of the fibers to create incredible strength and stiffness without compromising the ride quality.

Just my little rant.

But back to the subject. Go aero over light for a tri bike. And while a good fitter can get you into position on any bike, a great fitter is going to tell you that you are on the wrong bike. If your fit is achieved with some odd sized stem or layed back seatpost, it will fit. But it can create power generation issues and it can move the stresses the rider puts on the frame into areas that weren't designed to take it.

Try all the bikes (great choices BTW, wish I had that kind of money) and see which feels best out of the box. Then just a few small tweaks will put you into your perfect position.

JamieM,
I am glad to hear that the newer carbon is better designed. It bodes well for me and my frail- looking QR.
ironmike12, some carbon makers are starting to use lugs to give more flexibility of sizing (Guru, Seven) so that is becoming less of an issue, though cost becones more of one.
Jsoder, I think the best bet is to just buy Canadian. A good rule of thumb in all of life's pursuits.
Garth

It does look gorgeous. What is it with Canadian manufacturers and triathlon bikes? Pull the trigger if it fits
Garth

If $$ is not really a factor, then whatever bike fits you the best should determine your choice. In most cases, how the rider “fits� on the bike makes a bigger difference in Aerodynamic drag than the bike itself. From an article I read:

“Aerodynamic drag is measured in pounds per square inch, which means
that for every inch of you or your bike that is exposed to the wind, there is a pound of
resistance pushing against you. We reduce drag by making you “smaller� (e.g., tucking in so
that less of you is exposed to the wind) or by making you and the bike “smoother� so that the
oncoming air flows around you better.�

So if bike A has a better aero profile than bike B, but bike A does not fit the rider as well;
you would actually be better off buying bike B.
Like so many people have said in this and other threads, a good fit is the key.
Also, I read somewhere that until you consistently average 20MPH or more, then aerodynamic drag is not much of a factor. I haven’t been able to confirm this though…any thoughts on this?
- T

Wind resistance is a squared function of speed. Above 20 mph it starts to become much more significant than friction and rolling resistence. But it matters at all speeds. Look at riders in the Tour de France. The drafting effect is enough that Lance always had a team mate pulling even on climbs where they were going 12-13 mph.

Cheaper alternative than wind tunnel testing is a power meter. Ride a set route at a given power out put, and record time/speed. Ride the exact same route with the change in your equipment or position at the same power out put, and you can see the effect the change has on time/speed. Not as accurate as wind tunnel testing, but a good approximation.
You can do the same thing without a power meter at a set HR, but so many variables to HR (like being more exhausted, dehydrated in the second pass) that this becomes less accurate.

Go with the GURU, I bought a RaceLite two years ago, and I would buy another if I ever have to. It fits like a glove, is very Aero, and I'm figuring out how to make the motor better everyday!!!

Wow!! What a great wealth of information! Brian, I think you are on to something with this dimple thing. In fact, if my memory serves me correctly, the skin suits that Lance and the rest of the team use also have a texture to them...similiar to dimples, for the same purpose...to break up the airflow. I'm surprised that these teams haven't already experimented with this.

Here's a question for you experienced and wannabe cyclists like myself: Knowing what you know about all of these variables, if money were no object (let's cap it at $10K), what what would be your dream bike?

I've own(ed) Litespeed, Trek, Griffen, Giant, and Softride.

My Softride and Griffen are very close in weight at the 20lbs~

They are also my 2 fastest bikes on the flats and some light rolling hills.

The other bikes seem better suited for hills.

jsoder ~ id go for a pair of lighweight wheels ... at 6K a set they are hot ... Dura Ace 11 with a Cervelo P3 SL Carbon ... But I think we would be over 10K at that point. We would need to sell some of that Altria stock to found the rest of it :)

Here's a question for you experienced and wannabe cyclists like myself: Knowing what you know about all of these variables, if money were no object (let's cap it at $10K), what what would be your dream bike?