In the early nineties, Schwinn built Paramount models with both 700c and 26-inch (650c) wheels.

From the 1992 Paramount catalog:

The Case for 26” Wheels

Ask Product Manager and Cat II racer Dennis Lane why you should consider switching to 26” wheels and he’ll tell you the real question is why anyone still rides 700C in the first place.

“I’ve ridden a Series 7 prototype for the past two seasons,” he explains, “and the 26” wheels are faster in every respect.”

“Of course there’s less wind resistance with 26. And they’re lighter and stronger because the spokes are shorter. And the reduced gyroscopic force lets the bike change lines quicker, making it more maneuverable. And because they’re smaller and weigh less, they accelerate faster. Those are all points people pick up on right away in a test ride.”

“But what really sells them is the first time they ride in a pack. They can’t believe it! They’re motoring along at 25 or 30 mph, and realize they’re doing a lot less work – every time they jump it’s an instant bike length on the nearest rider. By the end of the race, they’re lifetime converts.”