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Discussion Starter · #1 · (Edited)
Which was the first campy (rear) derailleur to have a slant parallelogram? The whole Suntour slant parallelogram story has always fascinated me, so I was wondering how long it took Campy to release a slant parallelogram after the Suntour patent expired in 1984. I think I not only know the answer, but own one. Hint: Record didn't get it until 1990/91.

Edit: For the Bonus round, which Campy rear derailleurs had an adjustable "b" angle (there are two that I know of) and which was the first (this option disappeared with the intro of the slant parallelogram).
 

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Discussion Starter · #4 ·
I think you are confusing a slant parallelogram with a drop parallelogram; the slant parallelogram was patent by Suntour in 1964 and the patent expired in 1984, but Campy remained behind the curve for several years afterward.

Going for the bonus,
1st generation Chorus derailleur '87-'88?
Not the right answer for the for the bonus, but it is the right answer for the slant parallelogram, it was the first C-Record Chorus that an a/b selector for inline and slant parallelogram. The first derailleur to have a b angle adjuster was the 1985-86 Victory; this gave the Victory a 2 tooth cog advantage (28 to 30) over the other non-drop C-record derailleurs; in was also a feature with the new 1987-88 Athena gruppo.

In 1992, Campy was utilizing the the slant parallelogram in almost all (perhaps all) their derailleurs; the race derailleurs had been re-designed as a short drop (ala Chorus) and they reduced the max cog size of these race derailleurs to 26T; this meant in 1992 the Chorus derailleur's max cog size was reduced for 33T to 28T! In 1993 this was increased to a 28T cog size except Record which stayed at 26 for a few more years.
 

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I think you are confusing a slant parallelogram with a drop parallelogram; the slant parallelogram was patent by Suntour in 1964 and the patent expired in 1984, but Campy remained behind the curve for several years afterward. .
Classic Rendezvous decribes the 1974 Rally as a slant parrallelgram:

"The first edition Rally was controversial in Italy as the slant
parallogram style seemed to mimic Japanese derailleur design,
which was unacceptable to many Italians!"

"1980s: new Rally
with a different body, no longer slant parallelogram (less effective design)"
 

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Discussion Starter · #6 · (Edited)
Classic Rendezvous decribes the 1974 Rally as a slant parrallelgram:

"The first edition Rally was controversial in Italy as the slant
parallogram style seemed to mimic Japanese derailleur design,
which was unacceptable to many Italians!"

"1980s: new Rally
with a different body, no longer slant parallelogram (less effective design)"
The key to your quote is "slant parallelogram style". The Japanese slant parallelogram derailleurs had a drop style, meaning the derailleur sat parallel to the ground. Up to this point all Campy derailleurs bodies sat perpendicular to the ground. The new style of the 1974 Rally was called a drop parallelogram, but it was not a slant parallelogram regardless of what the writers of Classic Rendezvous believe. There is no way Campy would have stuck their neck out and violated a well known patent. It is actually well known that Tullio Campagnolo did not even like the slant parallelogram design which was evidenced by the lack of a slant parallelogram design until after his death in 1983, which was not produced until 1987-88.

Here is a YouTube showing the working of a 1st generation Rally. The Rally was also the first Campagnolo derailleur to have a spring loaded hanger pivot. As you can see the Derailleur body is an in-line parallelogram and not slanted; therefore it does not actually follow the contour of the cassette as a slant parallelogram would do, but bounces from cog to cog. The cause was the spring loaded hanger pivot that acted like the "b" angle adjusted too close to the cogs.


Next we have a Shimano LX long cage. While certainly worlds apart, one can first see the obvious slant of the parallelogram body and the movement along a slanted axis that did not exist with the Rally and no bouncing on the cogs.

 

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Discussion Starter · #8 ·
Thanks for the great video of the difference the slant parallelgram makes. I looked at the video for the Suntouur 7 and the Campy record too.
Yeah I tried to use the Suntour 7 video but the embed option was not available.
 
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