There must have been something in the water in the late 1970’s. Both Sachs (with their Super Sport) and Excel (with this - the Excel Dynamic) decided that this was the perfect moment to copy a 1958 design - the long obsolete Huret Allvit.
Unlike Sachs, Excel did not try to ‘improve’ every aspect of the Allvit, but instead faithfully copied it and then, at the last moment, added a spring loaded ‘cable saver’ to the cable clamp bolt mounting. The hanger proudly proclaims that this ‘cable saver’ design is covered by US patent # 3,903,751, first filed in April 1974 - which is a little interesting as Shimano had been using this design on their Lark since the late 1960’s.
The plastic tube covering the dangerously protruding ends of the springs is a classy detail, and as a final touch, Excel chose to rivet the tension pulley into place - it is not replaceable. The bitter taste of poor quality lingers long after the sweet flavour of a cheap price is forgotten - at least that’s what it says on my local plumber’s van - and he should know, because I can assure you that he forgot about a cheap price some considerable time ago.
In my collection of US derailleurs, resplendent with CNC jewellery and SRAM’s carbon composite masterpieces, the Excel Dynamic shares a proud position with the Elgin American as one of the two earliest US derailleurs that I own.
It serves as a warning to us all.