I'm on the hunt for another Simplex SX410, 610 or 630 rear derailleur. These are nice derailleurs that work well and don't break the bank like the Super LJ's.

My question revolves around other derailleurs that would work. The Simplex models I'm looking for are the ones that go into the non-threaded dropout and have a bolt that threads into the derailleur from the inside of the drop out.

What other derailleurs would work? I've seen a Spidel with this set up. Did Huret make any? I guess I'm looking to broaden my search for potential candidates.

i'm not 100% sure i understand what you are asking. you just need a derailleur for that type of dropout (without the threaded hanger)? if so, there are a lot of them. i replaced the broken plastic simplex that was on my UO8 with a shimano skylark.

like this one: https://www.disraeligears.co.uk/Site/..._style%29.html

hope that helps.

The Spidel you saw was made by Simplex, I'm sure. Some Hurets fit the older Simplex hangers, but they have to have the correct tabbed washer. There was a different washer for Huret, Campy and Simplex hangers.

I have four SX610's now. I like them.

Go with a claw type derailleur and just about anything will work. Otherwise, you will need a Simplex derailleur, which show up pretty often on ebay. You lost me at non-threaded dropout.

I should have said derailleur hanger. On my PX-10 the hanger is not threaded, thus a more modern derailleur with the bolt tightening from the front of the derailleur will not thread into the hanger. The Simplex fits into the hanger and then a bolt is inserted in the back of the hanger into the derailleur to attach it to the frame.

I didn't know about the different washers so I'm glad I asked.

Stick with the SX610. I've never paid more than $10 for one and they work great. I've never tried an SX410, but I just picked up an SX810 with a long cage.

You can also tap and reshape your hanger to accept any standard derailer, but I don't recommend it.

If I didn't know exactly what you are referring to I wouldn't have reponded. It was obvious from your first post that you weren't talking about some UO-8 witha derailer claw.

A Simplex dropout



A Simplex without the LED and with an SX610



A butchered Simplex dropout