Duopar vs Acera
 

I am contemplating some changes on my 73 Schwinn Super Sport. Currently it has a Stronglight 99 Triple paired with a Shimano Triple FD. At the back is a Huret Eco-Duopar working a Shimano 14-34 Megarange freewheel. The Duopar hangs from a Huret hanger bolted to the non forged Schwinn Dropouts. The shifters are Rivendell Silver friction bar ends.The Duopar is actually working pretty well and shifts through all the rear cogs. The Shimano Triple always seems to rub the chain and seems to have too narrow a cage.

My idea is to replace the Duopar with a brand new Shimano Acera M360 RD and the Shimano Triple FD with a Shimano Deore XT M735 FD that I also have on hand. I would shift them with some Shimano Ultegra 7 speed bar end shifters mounted on Rivendell Thumbies mounted on Schwinn 7188 Cruiser handlebars.

I have the Acera RD on two other bikes and they always shift perfectly. The XT FD worked well on another bike with a Sugino Triple.

What do you all think of this plan?
What is the best rear derailleur hanger for this application and where can I buy it.
I also replaced it’s Brooks Flyer with Brooks B67S to go with the more upright stance with the Cruiser handlebars.

Don't. Huret made the best derailleurs ever in their day. Acera is probably some of the worst derailleur I've ever seen on a bike.

Can't you machine a longer langer for the Duopar? I mean if your bike is French then it is a sin to put Japanese crap on it. I have machining supplies and a metal 3-D printer so I could make you one and sell it to you for $200.

Well I'm no paragon of C&V purity, but even I think it'd be sacrilege to put such a modern mech on a '73 SS

My own SS is also a '73, and I too have put more modern handlebars on it, but I kept the original Huret derailleurs because they work fine, and it makes me smile to use such old stuff.
I'd rather sell that bike and buy a modern one than put an Acera on this one. The Kona Dew Plus I bought for my nephew is a better bike in every way, but we don't talk about that stuff here.

If this were any other forum besides C&V, the answer would be different, but if we don't have an affinity for the older parts then why are we even here??

Plus even you stated the Duopar shifts well. What are you hoping to improve with the "upgrade"?

Matrk B

Grant Peterson of Rivendell says that the Acera M 360 is a great derailleur. He is correct.

Many people here have have installed modern shifting gear on their vintage frames. I am beginning to enjoy index shifting in my old age.

I have already determined that my M735 Deore XT FD has too small of a clamp. What FD would index the Stronglight 99 Triple well with the Ultegra 7 speed shifters and fit the over sized Super Sport seat tube?

Where can I get the proper derailleur hanger for a non Huret derailleur?

I also have a couple of nice Suntour VX-GT RD that I could install if the Acera ever breaks. LOL.

I used the same Acera for a few years on my Pro Tour when I had a problem with the OEM Cyclone. It works far better than it has any right to. I only switched it out for aesthetic reasons when I finally had some extra pesos in my pocket. The SunXCD that replaced it looks the part, but seems to function not quite as nicely. The rear triangle on that bike is chromed, though, so it looks better.

The best widely available claw hanger for a modern derailleur is probably the one from Sunlite.

Oh duh, indexing, of course! I couldn't figure out what you wanted the modern stuff for, forgot you were going to change the shift levers too. My bad!

I use both, friction and indexing on different bikes. I don't miss the indexing on the friction bikes, but I don't mind the indexing either, so I'm OK either way.

The R. der. hanger you need is common as dirt. You can use almost any brand other than Huret or Simplex. It doesn't matter if the hanger says Campy, Shimano, Suntour, Zeus or Gipemme, only matters that it has a threaded hole, and a notch for the rotation-stop at somewhere around 7 o'clock. Some hangers are longer, put the mech lower for a larger max cog size, but that's rarely a deal-breaker measurement, any length over a fairly broad range should work. Some (Campy) have 26 tpi threads where most have 1.0 mm threads, but that doesn't matter either, they're so close that either type of bolt will work with either kind of hole.

That hanger is sometimes called an adapter claw, so including the word claw in your search will get you more hits.

The original F. der that came on my SS is the only one I've used, but I have noticed over the years on other people's, that mechs with a steel clamp seem able to bend enough to fit the OS seat tube, just by using a longer bolt. Steel clamps are typically found on cheaper models. Mechs with alu clamp won't have the needed ductility to bend out, but might have enough metal to enlarge the hole, say by reaming, filing, Dremel or what-have-you. I wouldn't be surprised if there's a thread on it here somewhere.

Good luck and let us know how it comes out.
Mark B

Too bad grant40 doesn't know the difference between a Schwinn Super Sport and a French bicycle, or how to write a polite disagreement to your thoughts.

I think you are developing a wonderful plan for your Super Sport. Looking forward to pictures. Could fenders be in its future? :innocent:

I previously had a Duopar Eco on my touring bike when I ran it in 3x6 friction shifting. But I switched it to SunTour Accushift with an X-1 RD, and XCD FD and Superbe Pro accushift ready 7 speed down tube shift levers and a Winner Pro 7 speed freewheel. It indexes nicely and inspires confidence more than pure friction.

The Duopar pulley cage is a wonderful engineering curiosity but I ultimately found it to not be easily servicable when the upper pulley wheel started to squeal for lack of lube. I sold it on eBay and never yet felt complelled to go back the Huret derailleurs as cool as they might be in theory.

Thanks for you comment, Pastor Bob. I am trying to make the Super Sport easier to ride and spend more time in the rotation. I have now owned it 47 years. I will be attempting to mount the Honjo fenders this month. It should be a good time to do it while I’m replacing the hanger and rear derailleur. It has eyelets on top of the rear dropouts and behind the front ones. Also a fender hanger on the rear of the no longer used kickstand mount.

I will endorse this switch only if you send the unused Duopar to me after installing the Acera. Personally, if Grant Peterson says to do something, I generally do the opposite just on principle. If Jan Heine says to do something, I just ignore it since a few years down the road he will have changed his tune and will likely be endorsing what I had in mind in the first place ;)

Seriously though, Mrs. Daka prefers indexed shifting and her 1970 Super Course mixte is decorated with modern Shimano geartrain. Works fine, looks nauseating on that bike. I would expect an inexpensive Shimano derailleur to come with a hanger, but if not, any Suntour/Shimano/Campagnolo compatible one should work. Leave the Huret hanger with the Duopar, it would be harder to replace.

It's a Schwinn Super Sport not "Le Tour", which at least sounds French

Just for grant40
https://cimg5.ibsrv.net/gimg/bikefor...dfa72039f2.jpg

Lovely. I can practically hear Nina Simone singing a certain song in the background... ;)

I find myself agreeing with a whole lot of Grant Petersen's opinions/theories. I don't agree with his "put cheap components and ratty accessories on expensive frames" stance.

I fully support using indexed shifting and the nicest stuff that you choose to use. If it's the Acera, and you find it meeting everything you want out of it- go for it!!!

This bike probably originally came with a Simplex rear derailleur, which they did make some bad ones, but most people get the good ones confused with the bad ones and end up throwing them out. I have started hoarding Simplex plastic derailleurs of any kind and plastic Mafac brake levers as I know there will be a time when all of them will be thrown out.

I apologize for my snarky post. I failed to keep my inner alligator contained.

This Super Sport originally came with a Huret Alvit rear derailleur. I bought this bike new in 1975. I still have the Alvit.



I have new Acera M360 rear derailleurs on 2 other bicycles. They are all steel and index shift perfectly. I bought the silver versions new for less than $17. I think it will index ever so sweetly with my Ultegra Barcons on Rivendell Thumbies.

Does anyone know the size and threading of the Super Sport’s fender eyelets on the front and rear dropouts.

Do Rivendell Thumbies index or are they friction? Either way, put the stuff on the bike that makes you want to ride it.

Almost certainly Huret or Shimano, actually.

In the 1970s, Schwinn used "Schwinn Approved" derailleurs manufactured by 3rd parties. Per Mike Sweatman's Disraeli Gears website, Huret and Shimano supplied those derailleurs. In particular, Schwinn started using a derailleur branded as the "Schwinn GT300 Le Tour" on their top of the line touring bikes in 1973. That was a rebranded Shimano Crane GS. They'd been using other Shimano models since 1970.

They also started importing bikes from Japan made to their specifications during the 1970s "bike boom". I'm pretty sure that the bikes imported from Japan were lugged and hand brazed. They also used Japanese (Shimano) derailleurs.

The catalog photo of a 1973 Schwinn Super Sport can be viewed here, as well as the description. The catalog photo also shows a long-cage derailleur.

The frame is also identified as hand brazed; Chicago Schwinn's were not. So the bike is almost certainly a Schwinn-approved bike made in Japan, and the original derailleur on that bike was very likely a Shimano derailleur.

A 1973 Super Sport was indeed both Chicago made and hand brazed.

Top

Hondo6, the Super Sport was Chicago and hand fillet brazed. It is a well documented and interesting story that leads to the great interest in the SS. I’ve worked with 2 72s, and 3 73s. All have been Huret Allvit rear and the low end Huret front. The SS story is quite fascinating.

I think he meant the Silver ThumbShifter Mount: https://www.rivbike.com/products/z55...f0ecc1be&_ss=r

[MENTION=43632]top506[/MENTION] , [MENTION=494396]sd5782[/MENTION] : I thought the only hand brazed frames Schwinn made in the US were the Paramounts. I guess I was wrong. Probably won't be the last time today. :)

Learn something every day. Thanks for the education.