I've come across a blue Centurion LeMans with the Sport LX group set. The rd is indexing, the front is not. I'll have photos later tonight or tomorrow. I'm trying to determine a year but haven't found many Centurion lovers forums out there.

The bike only weighs 24lbs, which seems pretty light for a late 80's to early 90's steel bike. I'm getting it to buikd as a beater bike for when my new Specialized is parked for what ever reason.

Were these pretty decent bikes?

LeMans was a decent mid-range bike. Unless you paid hundreds of dollars, you did okay. More on Centurions here. In that time era, only the rear derailleurs were indexed. I think this was true pretty much all the way up to the advent of integrated shifter/brake levers. Using friction on the two or three chain rings in the front on road bikes was considered no big deal, especially since the may require regular trimming. Only the rears were indexed.

Really varied by year. Centurion, like a lot of brands, varied the quality of build and components almost every year. Most years got better and better, some went backwards. Like any vintage bike, the easiest way to date it is the component codes. Centurion is one of a long list of very good brands, that were marketing companies (had others make their bikes). Lotus, Centurion, Univega, Nishiki, and many, many more. Finding catalogs and info on these marketing brands is usually harder, but of course, they used the same components everyone else was using. So date codes are very useful, and higher quality bikes had higher end frame tubing and usually better components.

My wife has a Centuriion Lemans 12 mixte. Pretty nice for a mixte, but still towards the lower end.