Louisville vs Chattanooga Ironman

It may not be a perfect solution, but the site has most bike and run routes posted. These should give you a rough idea of elevation, and points on the course where some extra work is required - sorry if I've stated the obvious, but that's how I've done it for a couple of events.

I've done both, and the view from the back of the pack goes like this:

Choo is definitely the friendlier swim. The Louisville swim goes upriver, around the island and then down, but the current is really almost nonexistent. Choo swim is like being jet propelled. I'm a 1'20" IM swimmer and came in well under an hour.

In my humble opinion, Chattanooga had the friendlier bike as well. The course was designed to avoid most of the major climbs in the area. There are lots of hills, but really nothing scary. I did Loo during August, and it was hot. Once again I didn't feel the hills were that scary, but just relentless, although the last 10 miles or so were downhill.

Loo has the more straightforward run. It's pretty much flat, although again when I did it it was hot. There are some obnoxious hills at Choo - IIRC about mile 10 to 12 and 21 to 24. I remember thinking how much it was going to hurt the second time around after completing the first lap.

I loved both of these races and I don't think you can go wrong at either. If you have particular limiters you might want to choose the race best suited to your weaknesses. Just my 2 cents.

Isn't IMCHOO a longer bike by several miles, too?

Yep, the bike is 4 miles long, so technically a 144.6.

Thanks for the input. The swim is my strongest part, so the current at Chattanooga isn't a big issue. By moving Louisville to Oct, they've eliminated the hardest part - the heat. The websites for the races show Louisville bike as hillier, but the Chattanooga run being hillier. I think I'd rather deal with hills on the bike and have a flatter run.

I did Chatt in 2015 and like the others enjoyed the swim but they have slowed the current down dramatically form 2014 by working with the dam owner, TVA. The bike was a great course 4800 feet of climbing most of it confined to a particular 25 mile stretch that you do twice. Looks like IMLOU has hills all over the place!

Everyone is preaching the truth, that run is a bear. 1400 feet of climbing and it was all in two really significant climbs that yo do twice. There were a lot of walkers out there...