The Simplex Super LJ Derailleur

What is the best derailleur ever made? No less an authority than Mike Barry of Mariposa fame says it's the Simplex SLJ, and he's not alone. I've become interested in the SLJ since my new bike, an old French racer, is equipped with both the front and rear models.

Simplex has always made good derailleurs, but in the 1960s they made the error of using a new miracle material, derlin plastic. This material was very tough and very flexible. The derailleurs would wear out rapidly, deform under load, and be perceived as cheap. But the basic design was ahead of its time.

I remember as a youth getting a Campagnola Nuovo Record derailleur and being rather disapointed that it did not shift as well as a Simplex Criterium I'd been using. Today we know that the Campy derailleurs, as well as the brakes, did not match the performance of less expensive French components. But anything so expensive and beautifully made must be better, right?

By 1972 Simplex had to do something to show the world it was still the leader in derailleur technology. And their tour de force was the SLJ. It was strong, shifted superbly, could handle a wider range of gears than the Campy, and it was pretty. It had a spring on the upper pivot that allowed it to take up more chain which made it better suited to the wider gearing that was becoming popular. The SLJ was produced in both the normal and long-cage, or touring, version.

But it was too late. The public perception of Simplex was too far gone. Only the most knowledgeble cyclists and hard-core francophiles bought the expensive new derailleur. Fortunately several French manufacturers used them on their bikes until the mid 1980s

The following year Simplex introduced Retrofriction shifters. These were so clearly superior to anything on the market that I remember seeing many bikes with full Campy grupos, except for Simplex shifters.

The SLJ went through several updates. The most significant was the the change to a slant parallelogram. Production ended with the rare SLJ 6600. Greg Lemond used one for his World Championship win.

The SLJ front derailleur was also an outstanding piece of engineering. Strong and stiff, it was far superior to the light, but flexible and fragile Huret front derailleurs.

Today Simplex SLJ derailleurs, and retrofriction shifters, are much sought after by knowledgable cyclists. Many of the randonneur bikes built in Japan by Toei and other constructeurs use them, as do Alex Singer bikes. Even early Rivendell bikes used them.

Before we get too caught up in the past, there are modern derailleurs that shift just as well, probably better. But they sure don't have the character of the old Simplex.