The concept of a little vehicle that gives you a little boost sounds good, but bikes aren't very post-apocalyptic...y.
***Imagines a guy in power armor with a rocketlauncher strapped on the back and minigun in a basket riding a scavenged bike***
Snackish: pks pks pks. Kilgore: BBS is here, town is safe
Bicycle sniping is old school.