Originally Posted by cny-bikeman

Whatever is available locally to you - craigslist.org, newspaper ad, posters, etc. You might want to consider a 3 speed or other internally geared bike instead of a derailleur bike, but they can be geared too high with the original rear cog.

p.s. Pardon my asking but is English not your first language? Your grammar seems fine in most of your sentences but then falls apart for a word or two.