75lechamp 

I recently picked up a '75 PX 10, and am starting a build... I am not very familiar with these, and I'm finding there are definitely some idiosynchrasies, beginning with these Simplex delrin derailleurs. Good tip, btw, from another post here about how to combat the graying of the plastic - armorall does no good, but any kind of oil works wonders....

The main problem is the cracking of the plastic. With the front derailleur I think the crack is fatal.... So the question is what is a suitable replacement for this thing? I used to have a Huret Success front derailleur that had a cable running to it (unlike a standard Campy NR), which is how this thing operates. What have other folks used on their PX-10s when the plastic fails?



Note the crack in the limit screw housing - still works but is it fixable? JB Weld maybe...?


Cracked where the clamp hinges....


Cracked....

This is the cable guide.... so if I retain this, I need a cable/housing running all the way up to the derailleur...

3alarmer 

...the commonest available front derailleurs with a fitting for the cable housing stop are a few different ones from Suntour.

3alarmer 

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...also look at: PX-10 Information Thread. which has some general information, and a few links, but never really took off.

75lechamp 

Thank you for the link, 3Alarmer, I will definitely look at that.

As it turns out, I have a Suntour Vx front in the stash, exactly like the one depicted above!



Suntour Vx

Cable fitting....

thook

epoxy and delrin plastic doesn't work. neither does jb weld. i've tried. huret makes suitable francophile replacements for pugs, i think. but....then....so does suntour

oneclick 

You need a rear mech as well. While right now it works, when it fails, the next time you go for the big cog on the back you will put the mech into the spokes and then you'll be sorry.

There are Simplexes (both front and rear) with more metal in them that are less likely to crack. The SX410 rear would be a near visual match, and a long cage version was available (I think the the long and short cages on all these similar Simplex rear mechs are interchangeable).

75lechamp 

I agree with you, so I found a SX410 to replace it with. I thought about the possibility of adapting the Simplex dropout to permit use of a Campy or Suntour, but that looks like irreversible surgery and a pretty complicated process. Will try the SX410 for now.... thanks!

bertinjim 

That Simplex BB clamp-on guide can be used with or without a cable sheath for a front derailleur. Look inside the non-drive side and you will see that it is recessed to act as a cable stop or to have the cable wire pass straight through as a guide only.

75lechamp 

Just wanted to get some confirmation about what I am dealing with here. The seller indicated he had been told it was a 1975 PX-10. From my limited knowledge, I think I agree, but here are some clues:



As found... has a Brooks Pro (date '73), Stronglight 93, Lyotard 45 pedals, Weinmann concave rims (will relace to tubies), the usual Simplex plastic derailleurs...

Looks like graphics ca '75

Looks like graphics ca '75

Mafac Competitions

Peugeot Trophy high flanges...

Downtube Reynolds 531 decal, or at least it appears that way.... seems to indicate forks and stays as well, not just 3 mains...the forks do not have the triangular decals...

I read a couple of posts indicating 7 digits would be 70s, while 6 would be 60s, but other than that, not really conclusive...

Pcampeau

I believe your PX10 is from 1973. 73 is the last possible year to get black Nervex Pro lugs. By 1974 they were using white lugs of a more plain design. Here is my 74 with Simplex SLJ derailleurs. The SLJ upgrade was not my doing. If the bike didn’t already have these derailleurs at the time of purchase I likely could not have afforded the upgrade. If cost is not prohibitive, I do recommend them, otherwise SX410 will Closely look the part and shift quite well. Probably what I’d have done if I had to pay for it.

75lechamp 

That is a beautiful PX10! 1973 would make sense based on the date of the saddle, if indeed that is original.

In my process of checking out the bottom bracket, I found this bit of interesting trivia.....



This was what amounted to the bottom bracket dust shield. So, the mechanic had at least one Oly in the process...."It's the Water..."

10/15/79 - bearings looked pretty good and races as well.... I don't think the grease went 42 years without being changed....

oneclick 

I think the guide does not end far enough back to have the cable clear the seat tube.