I hadn't checked my local CL for a while but yesterday decided to take a look and found a 1984 ST500 for a reasonable price. I already own a 1989 ST400, which one would you keep?

I like the 1989 a lot but I know the components are are not the best. I like the Suntour indexed shifting and the paint is in better condition. All the components are original except for the seatpost and handlebars. It has Modolo handlebars that are pretty comfortable but wide.

The 1984 is very cool. I haven't done anything to it yet. It has some bad touch up paint work but I can live with that. It has most of the original components except the rear DR. The Suntour Tech L was replaced with a Sachs Huret Duoport Eco (from what I have read the Sachs Huret is supposed to be an excellent DR). Also the shifters are Campy NR and the brake levers are Modolo Flash. I also like that the 1984 has brazed on cable guides instead of the plastic ones which I know are a pain to replace.

In a perfect world I would keep both but I live in an apartment and a baby is on its way so one has to go.
1984


1989

1984.

Unless you were planning on using those fork low rider mounts, I'd probably go with the 1984.

I don't know if I'd like the half step gearing, or the non-aero levers, but I prefer the color and the swoop of the fork.

And how many 1984 Cannondale's will you ever come across?

Both!

I didn't know that could be an issue. Well, I don't see myself using the granny ring to much in Chicago.

I'm teaching myself to use half-step, and it's fun!
+1 to keeping the older one.

Keep the '84 but swap the shifters, RD, Brooks, and brakes before you sell off the '89. If you want to part out the '89, I'd be interested in the crankset and BB.

The steel one.