Originally Posted by
top506
The actual attachment is from the rear of the RD. The Allen socket on the front is only to adjust spring tension. There's a pretty good blow by blow procedure here on the forums somewhere.
Top
Ok, I see
Originally Posted by
bikemig
I'm running the Simplex SX 410 RD on my 1982 Peugeot PXN 10. It came stock on the bike. It can handle an impressive amount of chain for a short cage RD. In fact, that's true with a number of simplex RDs. Plus they have upper and lower pivots and shift better than a campy.
Here's a good description:
https://mariposabicycles.ca/2016/01/...ng-derailleur/
I'm running 50/36 rings and a 14-28 freewheel on the PXN 10; the SX 410 handles that nicely.
Velobase has it handling a max cog of 30 with 30 teeth of chain wrap. I have used that RD with a 30 tooth in the back. It worked fine.
VeloBase.com - Component: Simplex SX410 T
Personally I wouldn't run a triple. I'd go with a stronglight 86 bcd crank (or the TA if you prefer) and run it with smaller rings (say for example a 48/32). If you get a 13-28 6 speed suntour ultra freewheel, you'll end up with pretty decent gear ratios. Think about cutting out the top and the bottom a bit and focus on the middle gears. There are always trade offs in building an old bike. I reckon that's part of their charm.
I have a 70s Mercier 300 I need to build up and that's more or less what I'm going to do. I want to be able to climb some hills on that bike.
Thanks for the tips, the SX410 seems the one providing the most flexibility and solutions. A double crank would be ok if, as in your case, you have a small enough inner chainring and a large FW, I didn't think old front derailleurs could handle a double 50-36, interesting. By "cutting" do you mean avoid extreme crossing like big-big or small-small when installing a triple?
Originally Posted by
Phil_gretz
On my 1971 Jeunet, I went with a Campy Victory crank that offered 116 bcd. That way, I could use a 47-36T combination. On the rear, I have 14-24 with a NR. This yields 89 gear inches on the top end and 40 gear inches on the low end. This range fits the purpose of this bike and matches my abilities perfectly. True, I spin out at 32 mph or so. Who cares?
Also, I'll confess that the Victory crankset isn't period correct at all, but it doesn't look harshly out of place either. So...
Interesting, thanks for sharing, admittedly my friend needs slightly higher gear ratios...
Originally Posted by
repechage
a key point to note, when using a “short” cage rear derailleur, note the comment about “bailout” - to get error proof and no damage shifting with a wide range triple and pretty wide range rear freewheel, a long cage rear derailleur is what is needed
Yes definitely right, unfortunately I couldn't manage to find long cage Simplex RDs yet, but it seems the SX410 could be a nice compromise, doesn't it?
Anyway, the picture is getting clearer thanks to all of you. The only remaining doubts concern SLJ derailleurs which would be the nicest Simplex solution: I admit still struggling to understand if and which one might be suitable for this project given
verktyg comments and tests in a specific thread on these derailleurs. Any suggestion is more than welcome...