Originally Posted by
BCRider
Perhaps because those early designers were smart enough to use 26" sizes to avoid the issue?
Of the five bikes I've got here currently three of them have 700C wheels. Two of them have geometry that can cause me to toe strike if my foot is in the wrong place and the bars are over quite strongly like they would be during a tight low speed turn. The other is a cyclocross bike which seems to have more room between the bottom bracket and the front axle and thus narrowly avoids the toe strike issue. But not by much.
Most, if not all, of my bikes have had toe overlap since my early racing days in the 1960s. I've never worried about it.
I can see why you came up with your guess that the early designers were concerned about toe overlap, given your experience with your bikes, but that wasn't the case. Again, they used 26" wheels simply because the Schwinn Excelsiors happened to be easily procured adult (i.e., 26" wheel) cruisers. No one was using 700c wheels in the U.S. back then except bike racers, and up until sometime before the early '80s the only 700c wheels available used tubular tires rather than clinchers.
It is true that cyclocross, which required bikes with 700c tubular tires, was a sport in Europe as far back as around the time of World War I, but it was largely unknown in the U.S. until comparatively recently. So cyclocross racing has been around much longer than MTB's, and yet cyclocross bikes have never used 26" wheels, so that also seems to disprove your theory.
The earliest mountain bikes were used mostly for downhill racing on Mt. Tamalpais at first, which quickly revealed that the original coaster brake hubs were hopelessly inadequate for the task of stopping the bikes under those conditions. (The grease would boil out of the hubs - hence the racers dubbing the most popular downhill trail Repack.) So a cottage industry developed to add rim brakes and then derailleurs (for riding to the top of the trails rather than walking the bikes up), followed by custom-built chro-moly frames with cantilever brazeons, etc.
Point being that no designer deliberately chose 26" wheels for use in mountain biking. For racing long, rough downhill runs on a mountain, the choice was adult cruisers with 26" wheels or nothing.
In short, I'm pretty sure that toe overlap was never a factor in the use of 26" tires for the early MTB's, but if you can come up with any citation of evidence from that era that attests otherwise, I'd like to see it.