Bikers’ friend tires will mend

While New York City’s bicycle world was rocked last week by news that a Bic pen casing can pick circular-key Kryptonite locks, it was good to know there are some constants, like Nat Martinez. Martinez, whose full first name is Natividad, has been fixing flats and adjusting breaks on E. Seventh St. east of First Ave. for the last 14 years, long enough to recall when the hardware store on the corner was a gay bar called The Tunnel. With a large clamp on the side of his wagon, he works quickly, finding holes in inner tubes by dunking them in a bucket of water and patching them, for only $4. Originally from Mexico, he moves around from time to time, but right now is living in the West Village.