mighty_mess

Hello everyone,

This might be a stupid question...

I've tried to find a clear answer and I can't. I'm restoring a mid 80s "Neuilly" peugeot for my wife, the derailleur is a Positron which I don't mind but cable replacement and parts are either impossible to find or too expensive for what it is. So I would like to change it. My wife wants indexed gears but I can't find a indexed derailleur with a "vintage" (using the word very loosely here).

I only know Friction system and internal hub. I understand that the indexing is in the gear levers but that there some indexing tuning within the derailleurs.

So can any derailleur work with indexing? Is it all in the Levers? For example would a Shimano 600 work?

Thank you!

fietsbob

No, there are incompatibilities, some intentional.


the RD has to move in, exactly the right amount for every click on the handlebar lever.
the engineers made it a closed set..


friction shifting is where various things can co exist functionally.

dabac

Positron (and to a degree Sachs Commander) is an exception to the rule, with an indented ridge/cam in the derailer providing indexing. I'd replace BOTH shifter and derailer for indexed parts matching your freewheel.
I haven't tried it, but I'd be surprised if the push/pull solid wire design of the positron shifter would work well with a traditional pull-only design.

mighty_mess

Thanks for the quick response!

So could there be, with any chances, a known Shimano friction deraillers that would match a Shimano indexed levers? (or other brands)

Annoying, I can't find a good looking indexed derailler...

raymond1354

Not all do 'cause the derailleur needs to run parallel to the cogs on the cassette or freewheel. Others will have more experience than I.

Duopar can (I have done this for a long time), but "fidgety", needs to be used with care. Maybe others - simplex SLJ 6600??

If that is the weird positron with the weird freewheel cranks, cranks may also need replacing - I don't know for sure, but Shimano did make a system called positron which required only Shimano stuff ( see Shimano Positron FH derailleur (PF20)).

Hope this helps a bit.

r

FBinNY 

No, Indexing depends on derailleurs having specific geometry so the ratio of horizontal movement to cable movement matches the levers and cassette spacing. You may find some serendipitous matches that work, but the odds are against you having good indexing across the whole cassette.

mighty_mess

@dabac

Thank you for the response. Yes I wanted to replace both shifter and derailleur.

I actually don't mind the Positron (although the positron thumb shifter is pretty ugly!), it's the first time I've tried one and it worked quite well. The only thing that bothers me is that the solid cable isn't easy to replace and same goes for the parts, everything seems to be attached together.

hueyhoolihan

IME, rear derailleur's geometry dictates the ratio of lateral movement vs cable pull. it's mostly in the parallelogram's design. for friction shifting it is relatively unimportant, but for indexed shifting it is critical.

it's a gamble. if friction shifting is not an option, to be sure, i would go with a matched set of shifters/RD/cassette or freewheel.

mighty_mess

It is a Shimano FH400 Positron, but it doesn't use a weird freewheel crank (that sound crazy!).
So is that the case that Shimano's (rear) 6 speed freewheel will match any Shimano index derailleur?

Indexed gears seems more complicated to work with then friction.

mighty_mess

Cheers! Ok, I'm going to start looking for options as my wife definitely doesn't want to go back to friction. Might have to put the Positron back on until I familiarise myself with indexed RD models.

Is there any indexed RD that look 70s or early 80s?

zacster

You are getting into scope creep here. You'll replace those 2 items, then find you need something else, then something else yet again, oh, and the shifters aren't compatible with the brake levers, etc...

And you will need new cables and housing as only the newer housing works well because it doesn't compress. And on and on it will go, until you realize you could have bought a new bike with all modern parts that'll beat what you have for about the same amount.

mighty_mess

Haha! Sound familiar!

It wouldn't be the first time, but you're right, this bike is probably not worth the trouble as it's really not a high end one.

Thanks for the head's up!

MRT2

I got a little carried away restoring my wife's 1977 Peugeot this winter, and I paid a bike shop to do the work. Simplex derailleurs were no longer functional, and I also wanted to change out the bars, changing from stem shifters to thumb shifters, and getting some lighter wheels. And removing the big chainring and turning the bike into a 1 x gearing setup. I had the thought of maybe changing out the 5 speed freewheel to 6 speed. I left the mechanic with instructions that indexed shifting would be nice, but not absolutely necessary.

Anyhow, the bike shop switched from a 5 speed freewheel to a freehub and 9 speed cassette, then sourced a 9 speed indexed thumb shifter. As for derailleur, when the shop went this route, the plan to put a vintage Shimano or Suntour derailleur went out the window, and instead, we put a modern long cage Tiagra derailleur.

Did any of this make sense financially? Probably not, but my wife loves her vintage Peugeot, and no entry level city bike would provide the level of enjoyment of her Vintage Peugeot.

mighty_mess

@MRT2

That's true, if you love riding a bike it doesn't matter if it's made of carbon or tube pipe.

MRT2

And vintage UO8s have a reputation for their ride quality, despite being fairly heavy. I have a feeling that with the vintage Peugeot modernized, my wife will never again bother with her modern Trek hybrid, and will instead ride either the Peugeot, or her modern (steel) Jamis road bike.

fietsbob

Perhaps its time to take the Wife out to a Bike Shop and Just buy a New Bike.

the 'Just one more thing to Upgrade and it will be better' quickly escalated to a New Bike Price ..

dedhed

"IN GENERAL" Six speed and up (until you get pretty recent) most garden variety Shimano rears, both Mt and road, will index with Shimano indexed shifters. Fronts have less compatibility, but many front shifters are not indexed.
There are exceptions but most lower to mid range shimano "plays well together" if the shifters match the speeds. For example my daughter's bike is a mid '80's Schwinn that is running Shimano light action 6s stem shifters, shifting a 9s 105 rear derailleur over a Shimano 6s freewheel. Works great.
Going to "shifter" controlled indexing you do need to use "index" shift cable housing although usually isn't as critical with the lower speed counts.

My experience for FWIW

mighty_mess

That's interesting, I think I'm going to have a go at trying things out. It will help me learn indexing. I've just put back the Positron back on, the cable is rusty and the shifter also has some rust. Would be a shame to not change it after all this cleaning and new parts. it will do for now but not for long.

mighty_mess

Haha, this project was more about cleaning than anything, a part from new cables and tires. We like the old bikes better

fietsbob

Have a Happy spending Spree.. strip down to the bare frame and start over .. wheels; Drive train; Brakes; All the cables ; And so forth ..

CafeVelo

What particular aesthetic are you going for? There's a lot of nice stuff around, often at low prices if you look.

squirtdad

Don't forget that good indexed shifting also is dependent on (or at minimum, greatly aided by) the design of the rear cogs (twisted teeth) and front crankset (ramps and pins). Just putting indexed shifters and even derailler on will not guarantee good shifting.

there are tons of variables depending on manufacturer, year, model, speed. There is more (some shimano deraillers, cassettes work with some campy shifters) and less (some durace does not work with anything else) compatibility than you would expect.

the only guarantee is to have matching deraillers, shifters, cassette, cranset and chaing. Any other than that may or may not work

mighty_mess

Nothing fancy really, probably Shimano as I guess it will be the easiest. Just something not plastic. Did you have something in mind?

Seems like Positron and SIS were the first mass produced index RD.

mighty_mess

Yes that's seem problematic, I will have to be patient, as always, and wait for a good opportunity to come up. She can still ride the Peugeot with the positron for now, I will be the only one bothered by it.

mighty_mess

A bit extreme...