State and Lake

Hello everyone, I am starting to get into road biking. Since for the past 6 months or so, I have been biking on my 7 or 8 year old mountain bike I got from Costco a long time ago. However, I am completely new to biking. Probably the only thing I know in dealing with bicycle parts is a carbon fork... I tried doing some research and I hear a lot of things about shimano, ultegra, Sora etc...all of which I am not too familiar with. So This would probably be the best way to get help, since I don't have that many biker friends.

I'll be using the road bike for training and fitness, and hopefully it will carry me through a triathlon, something i'm hope to do in the future. There are three bikes that I am looking forward on getting (two of them are on craigslist) but I don't know which is a better deal... I'm on a budget of around 400, and having seeing more bikes around, 400 is really low for a road bike. So I'm trying to get the most for my money, if i can.

used Schwinn Le Tour Classic (2011)
https://www.bikepedia.com/quickbike/B...ssic&Type=bike

Shift Levers Shimano Sora STI
Front Derailleur Shimano Sora
Rear Derailleur Shimano Tiagra


According to craigslist.. a 2010 Stage One Tour de France roadie:
https://chicago.craigslist.org/chc/bik/2576051492.html

Front Derailleur Shimano a050
Rear Derailleur Shimano a050

and again, on craigslist, a Centurion Ironman Road Racing Bike:
https://chicago.craigslist.org/chc/bik/2569960600.html

It says it has Shimano 600(Ultegra) components, I heard its race level which is great, i think.

All the bikes are said to fit my size (5'10"). Anyone with advice would care to give?

I'm also wondering if I should get a old frame but with high quality parts on it(like the Ultegra on the Centurian) or a new frame (2011) with decent parts(Sora/Tiagra)... Help!!!!