Hi fellas,

I am about to get a vintage road bike and would like to replace some parts for maintenance and to achieve a better fit. I am pretty new at this and could use some advice on whether or not modern parts can be used. For reference it is from 1989 and the part names are listed as necessary.

1. Will a 31.8mm diameter handlebar fit this bike? Note that the handlebar that I want has flat areas right next to where it attaches to the stem. The stem is a "Nitto Young" (random picture online so I can't measure it myself). The current handlebar is the "Modolo Mach 3". I tried searching for specs but couldn't find any so hopefully someone around here knows.

2. Which chain type is compatible? Are all chains the same (as far as fit goes) except for length? The crankset is a "New Shimano Biopace 42 x 52", the chain is a "Shimano Uniglide", and the cassette is a "Shimano 6 Speed 13, 15, 17, 19, 21, 24".

3. Is the saddle rail width standardized?

Thanks!