When Schwinn introduced the Stingray in 1963, it paved the way for the modern BMX bikes. It was Schwinn that was the first to mass produce BMX specific bikes on a grand scale in 1975 with the release of the Schwinn Scrambler.
The 1975 Scrambler came with stout HD S-2 Steel Wheels wrapped with 20"x2.125" Aggressor MX tires, Diamond tread rubber pedals, Hunt Wilde "Ribbed" Grips, Black Ashtabula Stem, Chrome Ashtabula Cranks, Chrome Varsity 39 tooth sprocket, Ashtabula Bladed forks and the Classic Schwinn "Banana" Seat in Black.
The Scrambler was a beefed up Stingray frame with extra welds at a few points on the cantilever portion of the top tube. In 1975, the chainguard was a bolt on style that was just like that of the Schwinn Varsity 10 speed except painted Black (Scramblers used the exact same 39 tooth steel front sprocket of the Varsity).
For the early 1975 model Scramblers, the kickstand was a bolt on type. The handle bar that would become the industry standard for years to come, was simply a Stingray bar (rise, sweep, and complete measurements) with a crossbar welded in for strength. The crossbar was flattened at the ends so that the single stem produced by Ashtabula would fit easily over it during installation. Scrambler frames, like the Stingrays they evolved from, ran 13/16" seatposts.
The 1975 International Bicycle Show (that would later evolve into Interbike) featured a Schwinn display with several prototype (Diamond Shaped) straight tube frames. They used Chromoly tubing and borrowed the huge seat tube from the Schwinn Paramount line of high end road race bikes. By early 1976, these were released as Schwinn's top of the line race frames, the Scrambler Competition Model.
These are two of the display frames from the 1975 Schwinn Display. Note that they are both longer than the production Schwinn Scrambler Competition Model frames and both of these have bolt on kickstand mounts with no chainguard tabs.
This one isn't even split at the top of the seat tube (to allow clamp down on the post). Serious prototypes here.
May 1976 Production Scrambler Competition Model.
1976 Schwinn Scrambler (Stingray type)
More to follow.........
This post has been edited by Ken Pliska: Oct 14 2008, 01:57 PM