Dynamax

From a 1970's French-made bicycle I'm fixing up for my son.  Nice badge design.

The consensus is that Dynamax was a North American brand of Motobécane.  That company was founded in 1923 to make bicycles and motorcycles, eventually becoming one of the largest manufacturer of these machines in France.  Bankruptcy overtook it in 1981, when it was bought by Yamaha. Today, the Motobecane brand is used on Taiwanese bicycles imported into the U.S.

In 1978, Canadian Walter Muma rode a Motobécane Mobylette moped 18,660 kilometers across Canada and Alaska.  He explained that he wanted to see the Canadian north before the huge mining enterprises changed it forever.  Shades of Raymond Murray Patterson fifty years earlier.