Founded by Karl Altenburger, a professional cyclist in the 1930’s, Altenburger was mainly famous for manufacturing aluminium rims and brakes. By the time I came to experience Altenburger products (the 1970’s) they were irritating items that promised much - but just failed to deliver. In particular their brakes were extremely similar to those of Weinmann (a famous Swiss company) but slightly less accurately made and missing the tiny feature that was the key to painless adjustment. When UK manufacturers ran out of Weinmann they would often fit Altenburger as a temporary stop gap - and bicycle mechanics all over the country would groan. Maybe things were better in the 1950’s.
Altenburger’s most distinctive product was the Synchron brake which foreshadowed the Shimano dual-pivot design.
Frank Berto reports that: