lajt

I just watched a good YouTube video that demonstrated how an inline parallelogram derailleur works, and how the slant parallelogram improved on the design so the derailleur follows the slope of the cogs.
But how did the old ones feel on a ride? Like if you had a Campagnolo Nuovo Record from the 70s, and it's clean & smooth, with a nice clean chain, smooth bottom bracket etc--how does it feel when you're riding and shifting? Especially since you're a rider from the future and you know how the newer stuff feels; does the old feel clunky by comparison? Or still very wonderful and smooth?
(I've never actually ridden on a bike with those old Campagnolo parts, just admired them from afar.)
P.S. Why did those Campagnolo Nuovo Record derailleurs stand so vertical? Was that unique to Campagnolo, or did all inline parallelograms look that way? If you look at this pic, the Dura Ace is shaped like the number 7--almost horizontal, then angling back 45 degrees--whereas the Campagnolo is just vertical:

bikingshearer 

There is a whole book dedicated to this and related questions called The Dancing Chain by Frank Berto. It discusses these issues (and others you never knew were issues) and has a ton of great photos and Daniel Rebour drawings. I recommend it highly.

As to your questions:

Why the straight drop for Campy NR's? History. When rear derailleurs moved to the rear drop out in the late 1940s/early 1950s (Simplex and the Campagnolo) gear ranges narrower - as in much narrower - than you see today, and the vertical drop design worked just fine. RD advances wnet hand-in-and with increased range in rear cog sizes. The drop "7" design was an attempt to permit better shifting over wider cog spreads. Campy, Simplex, Huret, and other Europeans makers didn't follow this trend for many years because they didn't have to - they were sellng plenty of RDs, thank you very much, and weren't interested in what the Japanese were doing. Suntour came out with the slant pantograph, a significant advance, in 1964. When their patent expired in 1984, Shimano was ready to make full use of the improved design, with Campy lagging by a couple of years. Suntour ultimately lost out because they made a few mistakes on the late 1980s and into the 1990s. So did Shimano and Campy. Shimano was big enough and devoted so much to R&D that they survived their mistakes. Campy was revered just enough and was just big enough to survive its mistakes. Suntour was neither big enough nor revered enough to survive its mistakes.

Which shift better, modern RDs or older ones? By pretty much any objective measure, modern ones do. That's the same as saying that, by all objective measures, modern automatic transmissions in cars shift better than 1960s or 1970s manual transmissions. That doesn't keep some people form loving old manual transmissions far more, and well designed ones work well, but not as easily as the automatics. The same is true with older versus newer RDs.

Also keep in mind that there is more to making a RD that shifts well than the shape and angling of the parallelogram. Positioning of the jockey wheels is very important. Compare the placement of the jockey wheels on a 1950s Campoy Gran Sport RD with a late 1960s to early 1980s Campy Nuovo Record - the placement of the wheels and where their cage pivots are quite different. That is not an accident.

In preparation for launching their slant pantograph RDs in 1984 when Suntour's patent expired, Shimano did a a ton of R&D to establish the optimum positioning and size of the parallelogram and the optimum placement of the jockey wheels and pivot point for the cage relative to the cogs, each other, and the other pivot on the rest of the RD. The result was excellent shifting geometry that everyone - yes, including you, Campy - copied for at least the next 25 years

Bottom line: A well designed RD from anytime after about 1950, properly set up and not too worn, will shift fairly well across its intended range of cogs. A well designed slant pantograph RD will be easier to shift crisply and accurately than an older non-slant pantopgraph or a straight-drop design. Does "easier" shifting mean "better" shifting? That, like beauty, is in the eye of the beholder.

SurferRosa

I think you mean "do" (present tense), and the answer is "simple, complimentary and without much fuss."


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Chombi1 

Straight parallelogram derailleurs do shift OK, most of the time, just a bit slower shifting and a bit less precise that offset pivot (Like Simplex SLJ6600) and slant/offset pivot (Like Suntour Cyclone Mk II). They usually require more overshift action at the lever to shift and more "trimming" after shifting. Their design simplicity though, seems to give them more reliability and ruggedness. That's why many pro and amateur racers still loved using straight parallelogram derailleurs like the Campy NR and SR right up until the beginning of the mid 80's, even though most other makers moved on to the later offset and slant/offset parallelogram designs.
As already noted, shifting performance on straight parallelogram RDs do benefit a lot from proper, careful adjustment. While offset and slant/offset parallelogram RDs are not as sensitive to this.

lajt

bikingshearer , thank you for the tip about the book! I'm going to read that for sure. I appreciate the thorough writeup about the history, too; I didn't know any of that. It's really fascinating.
SurferRosa , you are right, present tense. I think I was stuck in the time-traveler concept of going back to the 70s (and those are both gorgeous bikes!).
Chombi1 , thanks for the response. You've made me want to try riding one someday. Maybe that should be my next build...

BFisher

The biggest improvements in shift performance have come from chain and cog tooth design.

When kept with the designed gear range, a Campagnolo Nuovo Record paired with a KMC Z or X series chain and Hyperglide-style cogs is butter smooth. New pulleys also help. This bike is set up with 52/40 chainrings, and a 14-24 6 speed freewheel. It is one of the smoothest shifting friction setups I have ever had, including many Suntour setups.

steelbikeguy

Derailleurs have always been about the search for a good way to shove the chain from one cog to the next. Some have been more sophisticated, and some less so....
Definitely get a copy of the Dancing Chain! That will keep you entertained for a long time, and thoroughly explain all of the ways that have been explored on the path to our present technology.

As a teaser, you might want to look at the Vittoria Margherita. This was a derailleur from the 1940's that just used some metal fingers to shove the chain left or right as the rider backpedaled.
https://steel-vintage.com/taurea-vit...ad-bike-detail
The Campagnolo Cambio Corsa is another example where metal guides were used to move the chain left and right. The novel feature is that the proper chain tension was achieved by allowing the rear wheel to roll fore and aft in the horizontal dropouts while changing gears!
Dave Moulton's Blog - Dave Moulton's Bike Blog - The Cambio Corsa: Campagnolo's Early Masterpiece

As far as the usual 70's derailleurs, they do require more attention and care when shifting. The chain isn't as eager to hop to the next cog, so you typically need to move the lever beyond the final position in order to get the chain to make the change. Indexed shifting definitely made the process fairly mindless and something beginners could do well.

Steve in Peoria

lajt

Whoa! So bizarre and cool! Actually very creative designs. When presented with the challenge of shoving the chain from one cog to the next, I definitely wouldn't think of a derailleur--I would probably design something like that Vittoria Margherita.
Thanks for those historical links, this is really neat. I'll definitely get that book too. I'm ready for my next one anyway.

lajt

Beautiful Motobecane. That's interesting about the setup. I like friction shifting so maybe I will try a setup like this at some point.

cocoabeachcrab 

From Disreali Gears..."Frank Berto caustically comments that the Campagnolo Nuovo Record rear derailleur shifted poorly, but was so well constructed that it would keep on shifting exactly as poorly - forever."

rhm

As a general rule, any derailleur system that worked well enough to be put into production probably worked well enough. If it didn't survive the test of time, it was probably because of some other feature, such as difficulty of setup, availablilty of spare parts, or that type of thing.

A notable exception to that rule: derailleurs with one pulley wheel., like the Campagnolo Sport. I've never tried one, but I understand they are pretty bad.

But two-pulley systems tend to work just fine, within design parameters. I had a bike with a Cyclo Standard derailleur for a short while. Date code on the Williams crank put the bike at 1934, which was consistent with the other components on the bike (Resilion brakes, Brampton free hub, early Marcel Berthet pedals, etc. It had a twist grip shifter on the handlebar. I didn't mess with it. It shifted perfectly, very smoothly, and very easily, and it feathered itself. That's an advantage of the old two-cable mechanisms (Cyclo, Nivex, Simplex 3-4-5, &c)-- since they don't have a spring to pull them one way, it takes very little effort to push them one way or the other-- if the shifter isn't feathered right, the friction on the chain is enough to move the derailleur, and the shifter, to the smoothest location (though it may take a while). The shortcoming of the Cyclo Standard was not that it didn't work well; it worked great. The problem was that it was a pain in the neck to set it up, a pain in the neck to change an innertube, and these are serious shortcomings.


I have a Trivelox Model B derailleur on one of my bikes. It's also from the mid-30's. It's awesomely primitive, and it shifts only three cogs. So pretty limited, but what it does, it does quite well.


These modern derailleurs that mount to a derailleur hanger integrated into the dropout, and that shift flawlessly over 11 or more cogs, are pretty cool. Take the shifter and matching derailleur out of their boxes, attach them to the bike, attach the cable (included) and make one or two small adjustments, and you're ready to ride/! That's way better than fiddling around with a Cyclo Standard until you get it just right, and 11 cogs are definitely an improvement over 3 cogs. So, sure, the new ones are better. But it's not because the old ones didn't work.

sd5782 

I have to second the comment about shifted good as designed for the original setup. The gran sport on my 64 Frejus was just fine with the stock 14-22 freewheel and 47/50 front, but didn’t like much else. It crudely shifted a 14-26 in back and seemed maxed out chain wrap wise although others state more capacity. Running a Suntour VX now and bike and rider are both happy.

smontanaro 

I rode my ItalVega today. It has a Nuovo Record rear derailleur. The rest of the drivetrain is right in its wheelhouse (24T big cog, probably a SunTour freewheel and a SRAM 8sp chain). It shifts perfectly. I suspect others have mentioned this or at least alluded to it, but if you keep this derailleur within its design specs, it's fine. If you get out beyond its limits - too many cogs, too large a big cog, long pulley cage - you're likely to have trouble.

Chombi1 

As I noted,, you can make RD like the Csnpy NR shift pretty decently, if adjusted properly. But if you ride even a well adjusted NR back to back with a best of the early 80's friction RD, like the Suntour Cyclone MkII and you will definitely feel a big difference in shifting performance......

SurferRosa

I haven't found that to be true. Maybe I'm doing it wrong.

rhm

Either that or, like me, you just can't tell that subtle difference between "fine" and "even better than fine."