# 1972 Sport tourer custom six speed



## fatbike (Dec 14, 2018)

This was a fun build.


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## GTs58 (Dec 14, 2018)

Cool daily cruiser. I see you carry an extra section of chain for those unforeseen break downs.


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## Schwinn499 (Dec 15, 2018)

Very cool!

Here's my round towner ST.


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## juvela (Dec 15, 2018)

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Very nice; thanks for sharing!

Lots of build thought/planning in evidence here.

Creation of an American _porteur._

If I were going to build something with a single plateau drive train would need smaller than a 52T chainwheel.

But then I am an annuated flatal cloud.  

Last time I looked Portolandia was in possession of a few _cerros.  _

Drive chain appears it could divest of two links.

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## Metacortex (Dec 15, 2018)

Very cool! Note for reference that's a '75 model, the last year they were produced and the only year they came in Sky Blue. It probably has a head tube that was stamped in '72 (they were stamped up to 6 years before being brazed into frames), hence the confusion.


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## juvela (Dec 15, 2018)

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Thanks for this great information @Metacortex!  

1975 was also the final year for this pattern of Peyrard (NERVAR) Star series chainsets.

They received a cosmetic revision in 1975 for 1976 release.

All parts interchange between the pre and post revision versions.

Manufacturer catalogue pages of 1974:









Post revision look, 1976:





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## Metacortex (Dec 16, 2018)

juvela said:


> 1975 was also the final year for this pattern of Peyrard (NERVAR) Star series chainsets.
> 
> They received a cosmetic revision in 1975 for 1976 release...




Thanks for posting that info and catalog pics! I found that Schwinn continued to use the 1st gen. Nervar crank arms on 1976 Superiors, but only for the first month or two of production. Here is a link to an example built on Tuesday Feb. 3rd 1976 (note for reference it also has a head tube stamped nearly two years earlier in May 1974 https://www.bikeforums.net/classic-vintage/487879-located-1976-superior.html


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## juvela (Dec 16, 2018)

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Thanks so much for this great information @Metacortex !

IIRC 1976 was the relaunch time for the Superior model.  Remember it as a friend purchased one new in that year..

Found it interesting to note that Peyrard offered their sets with a shift smoothing ring similar to the one seen on the T.A. sets as employed on the 1971 Sports Tourer. 

Part nr. 6 on the Schwinn illustration below - 









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## fatbike (Dec 16, 2018)

GTs58 said:


> Cool daily cruiser. I see you carry an extra section of chain for those unforeseen break downs.



Ha! Seat security, I do not want to lose it through theft.


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## fatbike (Dec 16, 2018)

Metacortex said:


> Very cool! Note for reference that's a '75 model, the last year they were produced and the only year they came in Sky Blue. It probably has a head tube that was stamped in '72 (they were stamped up to 6 years before being brazed into frames), hence the confusion.



Heard of the pre stamping. Possible.


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## Metacortex (Dec 16, 2018)

juvela said:


> Found it interesting to note that Peyrard offered their sets with a shift smoothing ring similar to the one seen on the T.A. sets as employed on the 1971 Sports Tourer...




Yes indeed. A shift-improving ramp was a big part of the design of the iconic Schwinn double plateau sprocket assembly that was first used on 1968 model 10-speeds with one-piece cranks. The ramp or "curved or sloping annular surface" is shown as reference 26 in the patent drawing and was designed to "function as a guide means for the chain with which the sprocket assembly is used to assure smooth transfer movements of the chain into and out of engagement with the teeth of the sprockets..."






When Schwinn was designing the 1971 Sports Tourer they wanted similar functionality for the 3-piece T.A. crankset they were going to use, prompting the addition of an inner ramp ring seen *only* on cranksets supplied to Schwinn. Unfortunately T.A. could not supply enough to meet the demand for Sports Tourers requiring Schwinn to use the Nervar crankset as an alternative, and Schwinn insisted those also be equipped with a functional inner ramp ring.


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