Figured I better post this here.....mistakenly posted this over on the mechanic board...oops.

Finally took my 1987 Schwinn traveler 12 speed out for a somewhat longer ride tonight, after replacing the tires, adjusting brakes, checking the bike out on short rides, etc.....

Some noob questions......

I get a little bit of a low frequency vibration when I am peddling from a low speed in a high gear.....my tires are a tad low....not sure if this is due to tires or something else.....tires are brand new panaracer panelas, 27x1-1/4.....psi should probably be around 90-95, probably currently around 85psi+.

Some brief, but very noticeable chain slap when going along at a decent speed and then stopping pedaling and coasting.....enough to leave a lot of chain grease on the horizontal frame member just below the chain....does the rear derailer tension need to be adjusted, or is it possible that with the age of the bike, the chain needs to be replaced, or maybe the rear derailer.......or is this just normal for an older bike? (I seem to remember a lot of chain slap with my older 10 speed when I was a youngster.....)

A bit of noticeable flex in the handlebars at times......am already thinking of changing the stem to get the handlebars somewhat higher....and figured I would change the handlebars at the same time.....any suggestions for better drop handlebars?

A lot of this might just be due to my size.....am a clydesdale (mid 250s and 6'-0")

Last question.....would I be wise, with the age of the bike to clean and re-grease all the bearings?

And, fwiw, am loving the ride of the bike.....really handles well and is quite comfortable to ride.....definitely a keeper. Also, I want to do the work on the bike myself, if possible.

Thanks for any help!