Originally Posted by John E

The Simplex units gave pushrod fronts a bad reputation. The Campag. units are better-crafted and also better-designed -- note that the cage moves slightly upward while it moves outward, to follow the profile of a typical 3- or 4-tooth chainring differential.

I have owned two Gran Sports. I had to scrap the one on the Modell Campagnolo because a previous owner had not lubricated it adequately, causing the shaft to wear into the aluminum housing. Fortunately, the one on the Sieger, a bike I am trying to keep pretty original/authentic, is still in great working order. I am using it with either a 49-46 or a 49-45, depending on what sort of freewheel the GS rear can accommodate.