I have a couple of photos of this Super Course in the "Your Classic & Vintage Rides" thread (post #414, 3/21/09).
https://www.bikeforums.net/showthread...e-Rides/page17

I was downshifting, coming uphill to a traffic light, on the way home this afternoon when the rear wheel locked up. I'm not sure what happened, but the plastic spoke protector is now broken, the lower guide wheel has disintegrated down to its hub, the metal frame into which the guide wheels bolt is splayed out, and the black plastic Simplex frame is broken near the point at which it bolts to the frame. The rear wheel was pulled out of line and was jammed tightly against the frame near the bottom bracket.

I was able to get the chain onto the smallest rear and largest front sprockets, and straighten the rear wheel (all it took was loosening the quick-release lever and reorienting the wheel in the frame), and finish the ride home that way. This is, of course, a "10-speed," and I rode home in 10th.

I have a couple of old "parts" derailleurs (including a SunTour that has already given one of its plastic guide wheels to that Raleigh Simplex) but not enough to get the bike rolling again.

Any advice from the group? I could probably post a photo of the broken Simplex if that would be helpful. As the photos suggest, the green Super Course is otherwise in excellent shape.

My theory is that the chain went up and over the large cog, lodged against the spoke protector and caused the wheel to jerk the QR out of position. The chain lurching up like that was too much for the jockey wheel, and it shattered (as they are inclined to do). I think the root cause was improper low gear adjustment.

Do you want to replace the Simplex derailleur or switch to something else? The Suntour might shift better and you could move the other good Simplex pulley over, I believe. If you did that the shift levers would have to be moved through larger angles than you would be use to, but that's okay. No spoke damage?

Go with the suntour.

If you were attached to that derailleur, on the other hand, an identical one can easily be had. Just say the word.

Thanks, guys! I think auchincrow's analysis is correct. I've ridden the bicycle about 350 miles and hadn't looked at the adjustment of the stop screws for quite a while.

No spoke damage, jimmuller... and the wheel still appears true. Lucky there! I'd just whipped down a hill at about 35 mph but had slowed considerably going uphill to a traffic light, so I wasn't going very fast when it happened.

Sailorbenjamin, the trouble is that there is not enough left of the parts Suntour to cobble together a working derailleur. Both of its guide wheels are gone, for example, and it might be bent.

Roll-Monroe-Co, despite this being a nice vintage bike it is my ONLY bike here at home, so it's my "rider," not a museum piece. I'd resist permanent modifications, I guess, but certainly wouldn't object to bolting on another derailleur.

Are bolt-on Suntours readily available?

Thanks again for responding, guys! This forum is a wonderful resource.

Yeah, I'll send you one if you give me your address. You can email me at sailorbenjamin@yahoo.com

Thanks! An email message is on its way.

Smart move going SunTour. Can't tell you how many Simplex's me & my bud went thru back in the day before I wised up & went Suntour. On the same ride I wrecked the cage & his body disintegrated.

I'm reading this in a CSI voice over and picturing it happening in a series of slick close up shots zooming along the drive train.

Progress... I now have a nice used Suntour (thanks, sailorbenjamin!), but am having trouble mounting it. Does anyone who has replaced a Simplex with a Suntour remember what has to be done? The derailleur actually bolts to a black plate that mounts in the Super Course's dropout. It looks as if the plate's large hole will have to be reamed out a bit so the large Suntour bolt will fit through it, and (depending on the angle at which the derailleur is supposed to hang) some of the tab on the rear of the mounting plate may have to be cut off.

Before I do any of this irreversible modification I thought I should ask for some advice. I can snap a couple of photos if none of this description rings a bell. (I did look in the Mechanics forum, but they indicated C&V was better for this kind of question.)

The supercourse uses a claw dosen't it? Pics would be best. May just need the right one.

Thanks, Juls! Still learning about posting photos, but here goes...Here's the claw (I guess that's what this bracket is!), the "new" Suntour, how the broken Simplex mounts.

Uh oh. I didn't send you a claw. I wonder if I've got one. I'll check. Usually the LBS has them pretty cheap. You need Japanese and you have French. You could modify that one but they're so cheap that it's not worth the time.

At first I thought you had to modify the frame, but drilling out the claw on the broken simplex isn't a problem - its broken! Check the clearance for the thin nut that goes on the back. Once you get it mounted you may find you have to move the lever a lot further than you did with the simplex - the Suntour needs more cable to move a given distance than the Simplex did.

Oh, and sailorbenjamin, what is a Suntour Vista? Looks like a V but I've never seen that name stamped on one.

Thoughts on seeing those pics - One doesn't normally separate the claw from the derailleur, especially with it still on the bike! One reason is that its mounting is integral to the spring tension of the upper pivot. Simplex used different threads from everyone else so theirs aren't swappable to a Suntour. However you can buy a claw from any co-op or LBS for just a few bucks.

Just curious (and perhaps you already said), what is broken on that Simplex?

Here's a shot, Jim... The "message board" sizes I chose for the photos in my previous post is giving me a "file size too large" error this morning. Don't know what I'm doing differently. Hope you can see the crack, just to the left of the (spring-loaded) bolt that goes through the claw.

I did not remove the derailleur with the claw still on the bike; I put the claw back on, by itself, to take the above photo and illustrate how things mount. Replacing the large mounting bolt in the derailleur (on the right end in this photo), I found two small holes into which the spring tang could fit, probably to change the spring tension. The Suntour has nothing like that!

I'll check with the LBS where I bought this bike (from its consignment rack), about 15 years ago. I'm sure (well, I hope) they'll be able to help.

Thus:

Your pic may have been rejected if you tried to upload the file just as it came off the camera. That could have been 6M or more. since the forum is going to re-size it anyway, use a graphics manipulation program to shrink it, then post that.

As for the claw, the reason the Suntour has nothing like the Simplex is because Suntour did things differently and better, and when their patents ran out everybody copied them. In the Suntour design there is no upper pivot. It's a pivot, yes, but it isn't spring-loaded. Instead it is supposed to be pulled forward against a hard stop so that in operation it is not a pivot at all. There is an adjustment screw to set how far it swings forward. You set it for whatever works, with the parallelogram horizontal more or less. By re-positioning it you can change slightly the distance between the jockey pulley and the sprockets, especially the largest. If you view the parallelogram from the back you can see how it is angled downward on the inside edge. That means when it swings in and out the pulley cage also moves down and up. This was Suntour's great invention, best innovation in derailleurs since the derailleur.

Well, I don't think I have any extra claws, at least not in the box where they should be. There are other boxes but they're a shot in the dark.
Yep, it's a Vista. I think it's the one I had on my SuperCourse for a long time. At some point I replaced it with a Vxgt cause someone told me they were better but I couldn't tell them apart without wiping the grease off of the label.

Thanks for looking! I'll check with the shop on Tuesday (Monday's a ridiculously long day at work). I bet they can help, and if not I'll go after it with some of my tools. Juls's photo of what it should wind up looking like is very helpful.

I did just this today--- took off a broken simplex prestige. ditched the french claw, but kept its mounting bolt for the dropout. Luckily the suntour I found had a claw with it. The peugeot mounting bolt fit with the japanese claw just fine. Only thing I needed was a little bit more housing for the RD and put a new cable on too.

Kinda' hard to miss the crank in that one, izzinit? Before you pitch that one remove and save some of the pieces such as pulleys, pulley bolts, pivot springs. Not that you'd necesarily need them again but some peoploe do. The Simplex pulleys are unfortunately prone to breaking so people interesting in a restoration might want them. Also they are interchangeable with some other brands. (I could use a spring myself, not that I need one for a real application right now.)

Progress... and it's a little embarrassing! I FOUND A CLAW on my old, bent, parts Suntour. It was bent too (not sure what it should look like, I tried it that way, and no deal) but a little hammering on the vise straightened it out. The Suntour Vista is now on the Super Course, and I'm in the process of adjusting the various screws and angles. At the moment, when it's shifted onto the large rear sprocket (28-tooth) the head of the jockey wheel's axle bolt is either rubbing or is perilously close to rubbing that broken plastic spoke protector. (Earlier, the bolt head was actually catching on spokes. Changing the angle of the derailleur relative to the bicycle frame seemed to help.) I'll remove the broken plastic and shift carefully (if at all) onto that large sprocket until everything is adjusted and fitted properly.

Apologies for all the fuss, guys! Obviously I'm no bike mechanic and had never heard of a claw before.

No fuss-learning is what we do here. How about another pic of that pretty bike?