I'm digging through a ginormous box of French stuff right now, and am having trouble differentiating the various models of Simplex derailleurs. I know the Prestige are the plastic ones, and have a vague idea that 'SJ' denotes an alloy RD...but beyond that I'm hopeless. Some have model numbers, and some don't. I'm still learning the ins and outs of French stuff...is there a handy reference guide anywhere, or someone who'd like to lay out a few rules of thumb?

Thanks.

VeloBase

2 pages worth of a start on your project

and some more at Disraeli Gears
and have a look at Classic Lightweight, a few articles there
pay a modest fee and download some material from the National Cycle Library just type in Simplex

hope that helps

The less plastic there is on any Simplex derailleur, the better, but only till after the 70's. The exceptions to this rule are derailleurs like the model SX610S from the early to mid 80's which is mechanically identical to the much sought after, hard to find and ultra expensive, SLJ6600 Aerodynamic. Only real difference between the two is the SX610S has plastic infills under chromed sheet metal parallelogram arms...and that difference discounts it over 100 bucks under the SLJ6600 (NOS), and as far as I know, they two models shift very well with good reliability. Simplex has other late 70's/80's derailleurs that have cheap and expensive versions that have the similar differences.

Chombi

Prestige doesn't necessarily mean a plastic derailer. My Super LJ says Prestige on it. I don't know of any Simplex derailers with an "SJ" designation. The SX series derailers are the better ones and the SLJ's are the best. The SX series derailers have steel cages while the SLJs have aluminum cages and pulley bolts.

Thanks for the help, guys! All those pages are very interesting, although I confess that my questions are still multiplying...The latest piece I've dug up is an SX630, and it does look like a good solid touring mechanism.

I'm looking at Velobase and trying to figure out what the difference is between the SX610 and SX630.

Didn't the 630 have a longer cage?

Chombi

I swear I had read a post here in C&V explaining the difference between the SX610 and the SX630 but can't seem to find it. I'm pretty sure there were both short and long cage versions of the SX630 though, the long cage being the SX630GT.

There's definitely shorter cage and a long cage version of the SX630. A long cage came off Trek mixte I had and is now on my dad's Vitus 979. My Gitane had a shorter cage version of te 630. There's also the SX410 that looks almost identical to the 610/630 - I have one of those on a Peugeot PSV.

Almost identical?

I think not!

https://velobase.com/ViewComponent.as...=108&AbsPos=28

https://velobase.com/ViewComponent.as...=108&AbsPos=30

You're right - my bad. It's early in the morning.