1970s, Outside on a track, a group of boys on their bikes at the start waiting to take part in BMX race. Some are wearing full kit, some just a top and
VINTAGE 1976 MAG SCRAMBLER BMX BIKE OLD BICYCLE 70s SCHWINN MAGS Very Rare | eBay
The Wild History Of BMX - YouTube
1970s Bmx Frames And Parts | Wanted: Bikes, Trikes, Parts, Accessories, Etc. | The Classic and Antique Bicycle Exchange