You could add an aero bottle, or behind the seat sytem to add capacity. Personally I feel two bottles of sports drink for an olympic bike distace would be overkill. I go with one sports drink and one water. I'll take a gel about 10-15 minutes into the bike and have a second one in case I feel I need it towards the finish, but usually not until I'm running.

I suppose it could be different under really hot and humid conditions, but with 24 oz bottles you still should have more then enough fluid for an oly bike course.

I know lot's of folks who take a gel right before the swim. I tried it once and it upset my stomach, so haven't done it since. As with everything, try it in training first.

My $0.02

Everyone has a thing that works for them, but this is what works for me.

I don't eat too much before the race. About 2-3 hours before the race, I'll have some cold pasta, some bread and fruit. Watered down Gatorade too. About 30-45 minutes before the race, I'll take down a little bit of gatordate slowly and maybe like half of a gelpack(depends if I feel I have enough in me). Race goes, hopefully I'm out of the water in about 20 minutes for Olympic Distance. Once I on the bike and everythings set to hammer, I take a swig of water right there. After 15 minutes, I'll take a swig of water then a swig of Gatorade from my other water bottle. After 20 minutes after I started the bike, I'll rip off a gelpack that is taped on my stem and put the wrapper in my pocket. I'm friendly to the enviroment. =) I'll keep repeating those two things until I come in off of the bike which is hopefully around 1:05 later. So, I'll drink 4 times and gel pack 3 times. So, I'm running now. I only take water at the aid stations and have a gell pack in my pocket just incase I bonk. Race ends and I go get a nice long massage. =)

Hope this helps. Good luck!

PS: I wouldn't recommend just a sports drink for the entire race. Watered down gatorade or a bottle of each works for many people I know.