Before compact cranks were adopted by the road community, they were used as the standard for mountain bikes. Compact cranks (110bcd) date back to the early 1990s. Shimano did make them in that vintage to answer Suntour’s MicroDrive crank standard.
Once external bearing bottom brackets came out, Shimano (and most other companies) abandoned the compact crank because the smallest chainrings would not fit over the external bearings. Shimano went to the 4-bolt (104bcd) configuration that they use these days which allows the granny gear to have a larger bolt circle to clear the bottom bracket. That’s about the time that they went from compact triples to compact double chainrings for road bikes.
These days Shimano still makes a compact triple in square taper. They are at the Alivio level and are very reasonably priced. Both Sugino and FSA make nicer quality, square taper compact cranks for road bikes.
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Pete
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