Welcome to Bike Forums.
for riding flat terrain, a lighter bike won’t make you faster. But a new bike always inspires, even if only for a while.
as to which new bike? Best to visit a good bike shop and ride a few. Flat bar, drop bar. Skinny tires, fat tires. Rim brakes, disc brakes.
a refurbed Miyata just might be more than adequate as well.
a World of choices to satisfy your (unstated) preferences.
Good Luck!
I like vintage.
