Step 1: New chain, tires, tubes, cables, clean and lube all bearings and derailleur pivots.
Step 2: ride it a couple hundred miles and see how you like it.
After that, you'll have a better idea what to do. Don't buy a lot of high end parts for it just yet. LA is a great market to go check out a lot of good used bikes on Craigslist, if you have the interest and the time. YOu may very well want to save your upgrade fever for a better frame. Though this one is not bad.
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● 1971 Grandis SL ● 1972 Lambert Grand Prix frankenbike ● 1972 Raleigh Super Course fixie ● 1973 Nishiki Semi-Pro ● 1979 Motobecane Grand Jubile ●1980 Apollo "Legnano" ● 1984 Peugeot Vagabond ● 1985 Shogun Prairie Breaker ● 1986 Merckx Super Corsa ● 1987 Schwinn Tempo ● 1988 Schwinn Voyageur ● 1989 Bottechia Team ADR replica ● 1990 Cannondale ST600 ● 1993 Technium RT600 ● 1996 Kona Lava Dome ●