73 Super Sport and new front chainring spider

[sd5782]

Newer member her, but I posted of my experience with changing the gearing on my old Super Sport. I liked the Ashtabula crank but wanted more age appropriate and closer ratio gearing. I posted this on another site, so I hope it is okay to link it here as others may find it interesting.

Ashtabula chainrings, why can't I do this? - Bike Forums

Classic & Vintage - Ashtabula chainrings, why can't I do this? - I am finally showing a little love to my well used and slightly abused 73 Schwinn Super Sport that I bought in 1975 as an 18 year old. I started by doing a lot of cleaning and a bit of bearing work. Being a bit older I thought some...

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[Eric Amlie]

Personally, I'd replace the entire one piece crankset with an adapter and an alloy cotterless crank.
That one piece crank is obscenely heavy, perfect fit for a Varsity, but should never have been used on the Super Sport.

 

[sd5782]

Let's put some numbers to it from my digital kitchen scale which should be accurate enough for comparisons:
Numbers don't include the Schwinn BB cups nor the adapter for the 3 piece adapter that I don't have.

Stock Ashtabula with rings and chain guard 3.99#
Stock Ashtabula with rings minus the chain guard. 3.53#
Ashtabula with adapter and 36T and 46T aluminum rings 2.70#
Sugino AT crank, races, spindle and 34T and 46T rings. 1.98#
No chain guard on this of course

So basically 2# of weight saved with the full 3 piece conversion. Nearly 1/2# saved just taking off the chain guard with the stock setup like we all did in the 70s and 80s because we knew about weight savings. Well over a pound saved with this inexpensive crank spider setup. In fact, less than 3/4# more to be saved with the full conversion and the things that go with it such as:
-fairly costly initially
-way more of a hassle with regular maintenance with pulling crank arms
-dubious durability after the regular maintenance of square taper arms
-square taper serviceability needing special tools and knowledge

I'm glad I found that bmx 110bcd spider adapter. I gladly kept all the maintenance and durability attributes of the Ashtabula along with its vintage charm.

Of course the 3 piece crank would be great on the stock bike but that gave us the Sports Tourer. How many of them do we see compared to the Super Sports? 1973 catalog prices:
Sports Tourer. $220
Super Sport. $153
Continental. $117
Varsity. $103

The Continental is about 30% more than the Varsity. The SS is more than 40% more than the Continental and the Sports tourer is in a way other price range being nearly double the cost of the Continental. I believe not many people bought the Sports Tourer as that put one into another level competing against some quality European bikes and their higher end appeal. Indeed, Schwinn hit a home run with the Super Sport as we see many available to this day. I bought 3 at my co-op for less than $75 for all 3 and am building 2 complete bikes with spare parts left over.

 

[Eric Amlie]

This is my interpretation of how it should have been done. YMMV.