Not only would the frames be stacking up, getting rusting/getting dinged, but also that model year handlebar, shifter, etc.
That’s a lot of storage for future parts. Factories don’t store things if the don’t have too, they make them as needed, or right before implementation.. That’s why they’re called factories.
Remember, they weren’t retooling the frames, just certain components. If they ran out of a certain years handlebar or shifter, that was changing to a newer design, they were already committed to that design. They would have, and did, use the new stuff regardless. They wouldn’t have re-re-tooled to make some more old design parts. They were committed to the new designs. The frame design didn’t matter because it stayed the same for long periods.
Just keep making the frames, what you hang off it doesn’t matter, the frame stays the same, there is no retooling or new engineering involved.
If backlog frames were the case, they never would have mixed multi year components on the same bike would they? They simply would have made more year correct accessories to stick on them.
i.e. 1,000 1969 frames= 1,000 1969 shifter types, despite the mid year change.
But, if they started selling far more frames that year than they had made components for, they would have, and apparently did, dip into the new stock to fulfill orders. Can’t have kids wanting bikes for Christmas and not getting them can we?
I suspect they simply couldn’t keep up with frame demand and ended up using the newer models components to fulfill orders on complete bikes.
From what I see on late year bikes, including mine, they ran out of model year component stock, due to unforeseen demand on complete bikes, and substituted the next model years upgrades on the old model year frames.
I have seen many later year frames with the next years shifter or handlebar design on them, sometimes both. They looked like the bike came with them, and the owners believe they are bone stock that way from the factory, too many to believe that every one was a customer change at point of sale.
I don’t believe there was such a thing as recalls on much of anything until the early 70’s. However, serial numbers were used, among other things, to identify problems in lots. (Tires are a good example of this) If, let’s say, frames had started catastrophically failing at one point during the sales year due to some unknown, or unforeseen, manufacturing process, tracing the problem back to the SN# date, which might have been erroneous, would have forced them to research many more months of frames than had actually been built during the manufacturing failure timeframe. That means EVERY Varsity, Heavy Duty, StingRay etc.that was, say, “built” in the September- to December SN# timeframe would have to be under scrutiny even though many had not actually been built until later than the SN# date.
Not likely in my view.
Could they have had storage areas for 1,000s of cranks that fit the majority of their models? Sure. I could put that many in my house storage room. Handlebars would be another matter, and frames would be completely out of the question.
Schwinn had many record sales years. I highly doubt they were ever sitting on a bunch of unbuilt frames and dropouts, at least not until BMX reared it’s head and the market had started to change.