Tektro Fork Mount Housing Stop w/Adjusting Barrel f/Cantilevers
This unit allows you to use traditional cantilevers or center-pull cantilevers without a housing stop on the headset. It is designed to clamp onto the front of the fork crown. This can solve a number of problems, and can improve cable routing by letting the cable get around even a low handlebar stem without a sharp kink.
Comes with cable adjuster and two recessed bolts of different lengths.
This is not intended for use with suspension forks. It may be possible to make it work with some suspension forks by mounting it on the upside-down "U" bridge that connects the legs, but it must not be mounted on the fork crown of a suspsension fork as it will cause unpredictable brake application as the fork responds to bumps.