ehcoplex 

I'm trying to figure out which SLJ front derailleur I've got, and more specifically if it's likely to be able to handle triple chainrings.....
Any helpful hints appreciated...



Also wondering about the cable routing for these... I'm assuming I need something other than the clamp-on Delrin over-the-BB guide, as there seems to need to be a short bit of housing from the guide to the derailleur camp pivot.
Thx!

The Golden Boy 

That looks similar to the SLJ that came on my Trek 720- minus the star, plus the added delrin (and decal falling off). Yes- mine handled a triple and I don't recall anything goofy about cable routing.

SimplexSuperLJ by Dave The Golden Boy, on Flickr

The Golden Boy 

OK, now that I see them together- they're really not all that similar at all- it looks like the mechanism is different. However, mine is marked Super LJ and does handle a triple.

ehcoplex 

Yeah, it's interesting- some SLJ FD models have the cable attach to the rear (yours), some to the front (mine). And on mine a cable-housing stop is built into the clamp pivot...

CV-6 

I have both type SLJ on triples. They both shift nicely.

SuperLJ

Your derailleur is most likely from the mid to late ‘70s. The earliest ones weren’t anodized. Simplex didn’t come out with triple-specific front derailleurs until the early ‘80s. Here’s a 1975 catalog scan, courtesy of Velobase. Note where it says “Double ou triple plateaux”.

bertinjim 

ehcoplex-

+1 for SuperLJ's comment. Yours is the earlier version and requires a short run of cable housing from a downtube cable stop to the ferrule on the base of the derailleur body at the hinge point. The later version shown by The GoldenBoy can be used with housing or with a bare wire. I've used both versions and they work well with doubles or triples. There is a version with a deep cage used for wide range doubles and triples. They work very well.

Chombi1 

That older front pull SLJ FD is actually better made/finished than the later back pull version.
If only there was an easy way to switch the cage of the newer one with the older on, I'd definitely do it.
BTW these SLJ FDs (Both front and rear pull versions.) tend to crack at the slot on tyd mounting band body where the parallelogram arm pivots, because the sharp corners of the slot tend to be stress risers.
Always check really close in that area before ever buying and using one on your bike.

ehcoplex 

Annnnnnnd.... I'm just noticing now what spellcheck did to the title of this thread......

ehcoplex 

Is this the spot you're referring to?

ehcoplex 

Any idea what sort of chainring range a non-deep cage SLJ FD can handle?

Chombi1 

Nope, it is on the inside of the clamping body, towards the back, right below the adjustment limit screws, where there is a vertical slot cast in for one of the flat steel parallelogram shifting arms. I did find one with a crack at that clamp hinge point too, so it is another area to watch out for cracks.
Twice I bought used SLJ FDs with a crack in that area, which kept me from using them on my builds.
Lucky one of the sellers took one back and gave me a refund.

bertinjim 

ehcoplex-

My shallow cage versions are running on a 52/38 Stronglight 93 and shifts beautifully. I have the other on a 52/42 Stronglight 104 and ditto. The deep cage is on a Bertin with 46/36/26 which also shifts flawlessly.

SuperLJ

If you look at the catalog scan above under “Capacités”, it says maximum difference between chainrings is 20 teeth, and minimum large chainring is 45 teeth.

SuperLJ

I can verify this. I had one break in exactly that spot.

ehcoplex 

Ah, I see where you're talking about.

ehcoplex 

So it seems like I *should* be OK making a jump from a 26 or 28t granny to a 42t middle?

SuperLJ

“Ecart MAXI entre plateaux - 20 teeth” translates to “maximum gap between chainwheels - 20 teeth”.

I could be mistaken, but I would take that to mean 20T between adjacent chainwheels, not 20T total capacity. I know that years ago I used this front derailleur with a 50/45/28 crankset on my Bertin, with no problems.

dddd

You had a difference of 22T, barely out of the recommended range.

20+20T no way.

oneclick 

He wasn't, but they crack the the point you circled as well.

And at the cable attachment eye...

SuperLJ

Well, obviously. I’ve never heard of a crankset with a 40T spread. Have you?

I don’t speak French, and I’m quite sure I’m being too literal with what I got from Google Translate. I think it’d be safe to say that the manufacturer rated this derailleur for a 20T difference, whether used as a double or a triple.

verktyg 

From the early 1970's on Simplex seemed to introduce variations and new model front derailleurs on a monthly basis. I've never kept track of them but I can probably dig up 50 different models from the bike boom until the bitter end???

Simplex SLJ derailleurs were first introduced for the 1973 model year. They were the first all metal Simplex derailleurs since the early 1960's. Sadly they were too little, too late to salvage Simplex's sullied reputation for making "cheap plastic derailleurs"!

The original SLJ FDs only came with a front cable connection and were intended to be used with a clamped on cable guide and a short piece of cable housing in front of the seat tube. SLJ derailleurs started appearing in the US market on a few high end French bikes like Peugeot PX10s and PX60s plus Bertin C37 models about 1974-75.

Simplex cable stops for front clamping FDs.



AV 326 front derailleur page from the 1973 Simplex catalog (probably from velo-pages.com). The Simplex label was recessed into the cast or forged parallelogram arm on the early SLJ FDs. From the beginning they were available both silver and gold anodized.

The cages on the early versions had pointed "lips". Gold anodized AV 326.



Later ones were rounded like these below.

Front and rear cable clamps.




The weak link in these most of these derailleurs were the front clamp hinges. I've seen both front and rear clamp models break here.



Another problem was the threads in the control arms that the cable clamps screwed into were short and frequently stripped out. Solution was to place a thin nut in the rear.

One last thing, I've had several the cages on SLJ FDs break at the inside weld (from attempts to move the derailleur slightly by the cage).


.
As far as capacity goes here's a standard SLJ FD with a 50-46-30T triple and a 13-30T FW. No problems.



They were unique designs that worked very well if only Lucien Juy hadn't been so cheap and made the derailleurs a little more robust in a few places.....

A Centime saved was a croissant earned!!!





verktyg

ehcoplex 

Thanks, verktyg, for the wealth of info!

So, what was the usual cable routing for an SLJ with the clamp on the front? From the down-tube clamp guide in front of the seat tube, or around the back? Seems like either way is a little bit awkward.... (sorry, my PX-10 is completely apart- I suppose maybe the routing becomes obvious when things are put together...)

verktyg 

Not quite the same as the SLJ FDs but these Simplex LJA200 front derailleurs had the same basic design. They were used on some Peugeot PX-10s from about 1972-73 to 1974-75. They worked pretty well, far better than the old Simplex push rod style FDs.



The cable and cable housing wrapped around the back of the seat tube and up into the hole in the hinge.




My 1980 Bertin C37bis came with a front cable SLJ FD. The factory kludged together the shift cable with some kind of plastic tubing and ran it behind the seat tube the same way. Problem was the bike had brazed on Campy style cable guides on the BB shell.



I lucked out and found someone who had a rear pull and needed a front pull.... Notice how I had to put a nut on the clamp screw because the threads in the arm were stripped out.



BTW. a lot of the later Simplex mid range front and rear derailleurs are a lot more robust. They weigh a few grams more but they last a lot longer.

verktyg

Iniezione 

To answer your question, as the person who pulled the FD to sell you, it came on the bike with the standard Delrin Simplex BB cable guide. A small length of cable housing connected between the cable guide and the derailleur.