Early Calculations

So, I know I am still in the prep phase of my training and I haven't even completed a baseline time trial for my individual legs, but I am still getting started at work and am not incredibly busy. That being said. I went ahead and made initial calculations for how to accomplish the 2h40m goal I have for Chicago. They will likely be adjusted as I see where I stand, but based on previous seasons, I have estimated where I will take out time to drop the 10 minutes. Here are my goal splits:

Swim: 35 min (2:20/100m)
T1: 3.5 min
Bike: 1:11:00 (21 mph avg)
T2: 2.5 min
Run: 48 min (7:44/mile)

By looking at my previous olympic results along with more recent data, I came up with those numbers. Now, here's my rationale:

My previous best swim is 38.5 min in Louisville in 2006. However, I am focusing on swim training since it is my limiter. Also, the Louisville swim was in a river where 1/2 was fighting a current. I think I can safely take out 3.5 minutes.
My bike avg has been around 19 for the last 2 olympics, but I improved my bike speed last year in my 1/2 IM training and did the St. Louis sprint tri (flat 20 miler) bike leg at over 21mph avg. I'm assuming the bike to be flat and fast since it's on lake shore drive (wind may be a factor).
My run is basically right in line with where I was in my last 2 olympics. It's actually 7s slower per mile than my 2006 run. However, I'm just hoping to maintain in this area and possibly use it as my wiggle room. If I'm behind schedule going in to the run, I'll still have confidence I can make up time.
As far as transitions go, I am usually slower than avg. However this year I will have a tri suit which will basically eliminate clothes changing to save time. I still overestimated here since it is a large tri, so the transition area is huge, plus wouldn't it be lame to not achieve my goal b/c my transitions were too slow.

So anyways, there's the initial gameplan. I figure if I put it in writing where the public can see, I will be pressured into really working towards it. My baseline time trials are in 3 weeks BTW, so then the fun really begins and I move into the base phase.