from sheldon's jabbery:

Royce Union
The most widely distributed Japanese bike of this era (the early 70s) was sold under the name Royce Union. This was a 10 speed, pretty much all steel except for the handlebar stem and the Dia Compe brakes. This bike was only available in one size, 20", which was considerably too small for an average American man. It was equipped with Araya steel rims, which were beautifully made, much smoother and truer than European steel rims of the era...but not strong enough to withstand the weight of an average American rider. This was partly due to design, and partly due to the fact that Japanese steel was not as good as European (nor American) steel.

Even though these bikes were not durable, they did have their good points, most particularly the Shimano Lark rear derailer. Although the Lark was quite heavy, it shifted markedly better than the French Hurét Alvits and Simplex Prestiges that were coming through on the bikes from Europe.