Local bicycle shop if needed right away. If you just need the inner wire you need a approximate length, match if the top that goes into the lever with whatever feral end you have (most likely round/flat sides) and remove old cable wire and route the new cable wire. I kept 2 extra cables on hand when I had my RadRunner. Gave them to the new owner when I sold it. The inner cable is around $5-$15 depending on quality. Ironically WalMart used to sell them, and not bad quality for the price.