Re: [CR] Simplex CX630 Rear derailleur

Example: Humor:John Pergolizzi

Date: Wed, 13 May 2009 12:39:23 -0500
From: John Thompson <>
Organization: The Crimson Permanent Assurance
To: CR List <>
References: <>
In-Reply-To: <>
Subject: Re: [CR] Simplex CX630 Rear derailleur

Jerome & Elizabeth Moos wrote:
> This is one of the absolutely bewildering array of models Simplex
> made in the late 70's and the 80's. I don't think anyone knows them
> all.

> Not sure I have a SX630 specifically. Usually the versions
> designated Super LJ, in this case the SLJ 6600, were all-alloy and
> very nicely finished. But there were numerous other models with
> essentially the same design using various combinations of alloy,
> steel and plastic, at a lower price than the SLJ version. So it is
> likely some bits of the SX630 were either steel or plastic or both.

I have an SX-660 here:

It's all-aluminum, not aluminum shrouded plastic like some of the less expensive Simplex RDs, but not finished as nicely as the SLJ-6600. The back of the cage does say "SUPER LJ" though. Shifts very nicely, too, thank you, especially with Simplex retrofriction levers.

Whoa, hang on! I just found an SX-630 (long cage) in my Big Pile o' Derailleurs! Feast yer eyes on this:

Also all metal construction. I got this to replace the SX-410 from my Gitane tandem that broke, but haven't yet installed it.

Here's the broken SX-410. Note the aluminum covered plastic construction of this unit:


-John Thompson (
Appleton WI USA