Shimano Front Derailleur CX70, dbsm - 17161
Shimano FD CX70 Here's a neat front derailer that's supposed to be for cyclocross racing bikes but it happens to work just great on Riv type bikes, too. The cage has a smaller radius than usual road derailers in order to better follow big chainrings that are 46t or less. And since using a smaller big chainring means the derailer will be lower on the seat tube, the cage is cut short so that the end doesn't bang into the chainstay. Riv frames have bb drops in the 70's and 80's so the banging into chainstay problem is very frequent with most front derailers. Designed to only work for double cranks but we've also gotten it to work good on some weird half step triple ring set ups. The minimal inner cage plate doesn't hit the middle half step chainring like a typical triple derailer cage does. The clamp is 31.8mm but it comes with an aluminum shim for 28.6mm seat tubes. Bottom pull.