While Campagnolo's Gran Sport was a breakthrough design, particularly among racers, and was the design that spawned many copies and imitators, another, superior parallelogram derailleur was introduced more than ten years earlier: the Nivex.
|Classic Nivex parallelogram derailleur. This example has a clamp |
for mounting to the right chain stay. Other examples mounted
directly to the stay without the clamp, for a more secure attachment.
Jan Heine, of Bicycle Quarterly, has praised the Nivex as one of the best-shifting derailleurs ever made. In a test of a 1962 Alex Singer, Heine wrote: "The Nivex derailleur shifted as precisely as always, but I had to adjust my technique. . . I had to stop 'over shifting.' With the Nivex, you move the lever until the new gear engages, and that's it. No fine-tuning necessary. The compensator lever on the spring keeps the chain tension constant, so every shift is exactly the same, no matter where you are in the gear range." (Jan Heine) Heine's respect for the Nivex is such that when he had a new, custom-built randonneur bike built in 2011, he had it built to use a vintage Nivex derailleur.
Notable frame builder Alex Singer was also a fan of the Nivex design. On Singer's bicycles, the derailleur was chrome-plated and prettied up. Unfortunately, however, apart from its use on some very nice cyclotouring bikes in the 40s and 50s, the Nivex derailleur just didn't catch on. Berto's book points out that it was first introduced during the economic recession that came just prior to WWII. Of course, the war years would have hampered the company's fortunes as well. Ultimately, the company didn't have the resources to market it to its full potential and production was ended some time in the 50s. According to Jan Heine, the French constructeur Dujardin purchased the remaining stock of parts and continued assembling derailleurs until the late 60s (Bicycle Quarterly, Vol.2 No.2).
Years after losing its marketing power, SunTour took a look back to the Nivex when it designed its doomed S-1 in the early 90s. Like the Nivex, it mounted to the right chain stay, with the parallelogram pointing backwards towards the rear axle. It really was, in many ways, an updated, modernized version of the Nivex. Interestingly, it had an indexing mechanism built into the derailleur, rather than in the lever as in most index-shifting systems. Unfortunately for SunTour, it was introduced at a time when the market was clearly dominated by the Shimano juggernaut. Furthermore, it required a special mounting boss on the chain stay so it couldn't be simply retrofitted to existing bikes. As far as I know, the only company that specified the derailleur on any of its models was Schwinn, on its '93 Criss Cross -- a touring/hybrid model. Without any other OEM support, and no aftermarket demand, the S-1 faded into obscurity after only a year or two.
Obviously, most derailleurs since the 1950s took their design cues from the Campagnolo Gran Sport design which mounted to a hanger on the rear dropout. Different manufacturers made incremental improvements to the design over the years, such as adding spring-loaded top pivots, or the drop-parallelogram which oriented the body in a more horizontal fashion, or even the slant parallelogram that canted the body so it pivoted downward as it moved inward for more consistent chain gap. All of those changes improved the shifting, but all of those incremental improvements did nothing more than to finally bring the "modern" rear derailleur up to the shifting performance available on the Nivex since 1938.