Gitane Tour De France
 

Was gifted a Gitane Tour De France 62cm bike. A bit big for me but I'd rather throw a saddle on a gift horse than look it in the mouth. Great bike. Used it as a trailer hauler for my special needs daughter and she loved it. End of the season the rear derailleur broke. I took it off and found there was a little coil-like spring at the hinge so it would no longer tension the chain. It is a bolt-on type derailleur. I have a derailleur from another old 10 speed. Before I go investing a bunch of time I'm wondering what are the chances the other derailleur will work on the Gitane. Or should I start scouting eBay for one just like the one that broke? As long as the mounting is the same I'm good to go right?

You may have opened a can of worms here. Can you post a photo of the rear dropout on the frame, where the derailleur was attached? That should show what kind of replacement derailleur is needed. It may be simple, or it may be somewhat less simple.

@jonwvara is being modest. His website is a go to site when dealing with the drop outs on an older French bike.

Derailleur Hangers Demystified - Red Clover Components

We'll need pictures but the easiest solution is likely to use a derailleur with a claw. The Gitane TdF is a great bike.

I will check out the resource and get pics uploaded as soon as I can. Thanks guys!

Yep, pics or it didn't happen. ;)
Was the old derailleur a Suntour Cyclone, by chance?

If it has friction shifting, most any derailleur will work as long as you can get it bolted to the frame.
Jon

Will get pics later today but this is what it looks like:
https://www.ebay.com/itm/Suntour-Cyc...4AAOSwJcxcwLEp

That price though :eek:

Is there a more (Ahem) economical alternative?

We need a picture of the rear derailleur and the hanger to figure out what will work. Is your derailleur mounted on a claw?

The eBay price is high. Those derailleurs go on this website for less and there are other alternatives.

Therein lies the rub, eh?

Get this one.
https://www.ebay.com/itm/SunTour-Cyc...QAAOSw4CRc3xj4

Pics!

https://cimg6.ibsrv.net/gimg/bikefor...85b77679c7.jpg
https://cimg7.ibsrv.net/gimg/bikefor...3f2680ffc5.jpg

I'd get one of these. to replace that Cyclone. Same great performance.

Looks like a nice bike. How bout some (drive side) full-bike pics?

That appears to be a Huret-style dropout, so the RD can swing way too far forward. I'm kind of surprised it worked very well at all, but a guess a strong enough sprung upper pivot overcomes it.

Now, @gugie can braze in a bit of metal to make it into a Campy-style, but not all of us have those skills. I'll bet you could glue something in there to make it work.

Agreed, it it does look like a Huret dropout. I had no idea that Gitane made a TdF with that style dropout. In theory, it shouldn't work well with a non-Huret derailleur, but it evidently worked well enough. You could install another Cyclone GT or equivalent and it will likely work about as well as it did before.

Nice bike, too. Mine is that same color.

I used to run a SunTour V-GT Luxe on a Raleigh Competition with Huret dropouts - it shouldn't have worked, but it did, and I wasn't even running a spacer or a tabbed washer. Gitane must have been running low on dropouts that day - I've seen Huret dropouts on comparable Gitanes, including what appeared to be a European market TdF equivalent on Asheville, NC Craigslist a while back - but I've never before seen non-honeycomb Huret dropouts on a U.S. spec TdF with the chromed rear before. I have no doubt they built them, though. Has Chas Colerich come around to see this one to add to his data points?

And I am eat up with envy - blue TdFs are particularly lovely in my eyes ...

@icecarver Just so you know- even that derailleur carcass is worth money- the pinch bolt nut and the adjustment screws are parts that get lost or broke and people need spares. The GT cage can be fitted to a non-GT derailleur. The pulleys are pretty pedestrian- but good pulleys are good pulleys...

And also to echo- that is a beautiful blue.

The easiest fix is to get a derailleur with a claw.

What "broke" on the derailleur?

These are very easy to overhaul.

Well when it broke it was obvious that it was no longer providing tension for the chain and looked "collapsed". Walked it home, took off the rear wheel, removed the chain and noticed that it was floppy at the hinge. Slowly took that apart and there is a circular coil spring inside with the ends bent out. One end had broken off. I attempted to bend the broken end out but it wouldn't engage the hinge part. So technically speaking all I need is that spring. Are those available anywhere or is that a unique part?

Replacement main springs for the early Suntour Cylcone are high on the C&V wish list. When you first mentioned that your RD lost main spring tension, I suspected it was a Cyclone. One member here on bikeforums even attempted (unsuccessfully) to garner enough interest to have reproductions made.

...I'd have to agree. If you're using it as a trailer hauler, and cash outlay is a factor (which it almost always is), you should be able to slap just about anything with a claw hanger on there and have it work fine with your friction shifters. And if you don't have a large gear range on there (which I can't tell from your pictures or description), you might not need a long cage rear derailleur at all. This opens up your range of possible alternatives to a large universe of used rear derailleurs.

If there's a bike co-op within easy driving range of you, they'll have a bin of them on a shelf somewhere. Or you might be lucky enough to live near some guy who runs an old school local shop where they repair and sell old bikes. Those are mostly in college and university towns. I'd grab one for you from the co-op here, but by the time I buy it and mail it to you, you're better off going local if you can. And whatever I grabbed would probably not have a long cage, if that's what you need. those are less frequently encountered.

As a lot of people here know the Suntour V-GT Luxe is a much more burly, heavy duty (and consequently heavier) sort of version of the Cyclone. This forum has seen several examples of the first version Cyclones have the main spring break- however, I don't recall seeing a member posting about a V-GT Luxe spring breaking. Is the main spring on those more heavy duty than the Cyclone's spring?

I don't know if they're stronger, but they are slightly bigger.
I actually have some NOS springs (Suntour P/N 926) that I believe are correct for the V-GT, but they won't fit a Cyclone.
@jimmuller may still have the exact measurements for the Cyclone spring, as he was the one trying to drum up interest in having reproductions made.

https://cimg5.ibsrv.net/gimg/bikefor...eb57826cf6.jpg

Yeah. Unfortunately it would have been an expensive project and only one BF member expressed interest in buying some to help deffray the cost. I don't have the exact dimensions but the biggest difference was the diameter. The shaft of the Cyclone will not fit into the spring because its own spring has a bigger inner diameter.

Helical springs are curious beasts. They are spec'ed for maximum windup, typically 90, 180 or 270 degrees, sometimes 360. Also spec's is right-hand or left-hand coil. Finally, critical dimensions are the thickness of the wire and total length. A helical spring is always torqued in the direction of tightening the coil. That makes the diameter shrink slightly, while the length increases by the wire thickness for every 360 degrees of windup. The increase in length is why the prong on one end is longer than necessary and parallel to the helix axis so that it can move further into the hole as the spring is wound up.