body weight & bike performance correlation

No, I wouldn't be disappointed at all!  If there's nothing to gain, then I don't need to lose the weight!

Considering all this, it's fairly amazing how much people will pay to shed like 6oz. off their bike, no?  I know for a fact people literally count ounces when picking out components for their bikes...is that all just a big waste of time and money?  Or is bike weight more relevant than body weight?

Duct tape two bags of sugar to your bike, ride one of your typical training rides and let us know the reuslts!  Don't have a clue what you might find out, but I am almost thinking about trying myself!

On a related subject, my wife and I were discussing my weight loss (45#) and its effect on some lower back problems I had been having.  She didn't think it really would make much difference.  I said, well, think about if you had to carry around a 40# bag of softener salt all day.  She then decided the weight loss prolly made a big difference.

Race results are great, but what you really need to impress your friends is a staggering W/kg.  So, lose the weight.

You will be slower, but not primarily due to the weight.  Those two bags of sugar are like to wreck havoc on your aerodynamics.  If you filled your water bottles (that you would carry normally) with something like coins, instead of water, that might make a good test.  Let us know how it goes. 

Not exactly a test, but definitely something that I saw and humbling, and may actually prove some of the questions. 

At Irongirl - I didn't use my aerobars, because I was fairly new to them, so I just used the drops (Road bike with clipons).

At Irongirl, I was cranking up a largish hill, and I passed on two ladies who HAD Tribikes and used their aerobars, but they look like they had a little bit of a relaxed fit.   HOWEVER, there was this girl who had a blue Cervelo, and she is a large woman. She's probably about 50-70 pounds heavier than me (I'm not thin).  She BLEW past me on the ascent of that hill so easily until she became a blip in the distance. All I could think of was, "OMFG!! Just to prove that you don't have to be pencil thin to do well on the bike." I was so happy for her actually!!".  Her fit was very aero - low in the front, straight back, and it was obvious that she had a great fit on her bike.  (Sadly, I passed her on the run...but that's okay!)

So, my takeaway from this is...it's really more the aerodynamics that plays a bigger role on the bike.  However, I also believe fitness also plays a role. I've passed some people on the ascents easily while they were on tri bikes and in their aerobars...probably because I ride big hills weekly, and they're not used to it. 

Weight reduction may help, but like Shawn says...it'll help better on the run. 

Basically losing weight is a small advantage on the flats but a greater advantage on the hills.

You can play with this calculator but for someone 5'10 @200 watts on a triathlon bike (CdA is calculated for you, I used all other defaults):

150lbs, 0% incline = 22.3 mph

160lbs, 0% incline = 22.1 mph

170lbs,  0% incline = 20.9 mph

150lbs, 2% incline = 16.2 mph

160lbs, 2% incline = 15.8 mph

170lbs, 2% incline = 15.4 mph

140lbs, 4% incline = 11.6 mph

150lbs, 4% incline = 11.1 mph

160lbs, 4% incline = 10.6 mph

Yes you would be fresher if you went the same speed up the hill as your heavier comparitive competitor, but then your buddy would use less energy getting down the hill at the same speed, so you'd be equally wiped when you reach the bottom.

If you were to go up and down the hill at the same effort you would both be equally tired at top and bottom but the heavier guy would be behind you at the top and caught up at the bottom.

~1/2mph?  To me thats worth dropping the weight - damn back on the diet