Duke Half IM ?

Haven't done the race, but have ridden the course many times.  Right after leaving T1, you encounter a gradual climb out of the park.  Then is a little triple hump hill, with a recovery downhill to follow.  You won't encounter the lion's share of the hills for about 13 miles, and then it's rollers after that.  You'll get to a few bigger hills by about mile 26. 

Then there's the big long climb on Hwy. 42 at about mile 35 that you will fly down and crawl up.  My top speed on training rides down the hill is 46mph, uphill is 15 (all out), running a 11-23 cassette on my tri-bike.

After that hill, the rest is relatively flat or rolling.  My plot of elevation change on the route I use (mostly the 1/2 course) shows over 2500 feet of climb.  You can probably expect closer to 2900 on your route.

You will probably see mostly tri-bikes on this course, as the climbs are fairly limited.  I am very comfortable on my tri-bike on this course (have ridden the roadie on it too).  You'll be wise to save yourself for the run; it's brutal.

Good luck!