The Stingray was a massive hit for Schwinn but later the marketing dept was asleep or flat out ignorant of trends.

Middle 1970's saw the start of kids wanting to race like moto-X and the Stingray was getting battered, literally. Then Skip Hess, an accomplished road cyclist and car drag racer created the Motomag 20" wheel. The kids soon realized they now had a robust wheel but the down side it was so good, the Stingray frames were new taking more of the brunt and breaking apart. That lead to Skip Hess and the dedicated BMX tough bike. Schwinn lacked and was tardy on this huge market.

Then when the adult sized BMX (aka: mountain bike) was on, Schwinn again was ignorant and finally offered the scrappy standards of the day, electro forged Sidewinder. Having all the resources, they could've launched a leader in that market segments. But in time they got their Japanese partners and made some terrific MTB's, yet at the mercy of the US factories crumbling under the forced UAW leaders greed. The Homegrown series was great but late. It get buried with hundreds of other new and emerging brands and the stigma of grandpa's Schwinn was pretty much the end.