Hey, I have just built up my RM Hammer.29 frame and am having troubles fitting a front derailleur. It has a high clamp as there is not much room down there between the frame and the rear tire. The seat-tube is 30.0mm, and all the spacers for front derailleurs are either too big (31.8) or too small (28.6). I have tried some cut PVC pipe as a spacer, it fits nice, but tends to slide around enough for the derailleur to move. Any help/wisdom would be much appreciated.