Complex sentence: In 1928, Weihrauch began international sale of bicycle parts and mechanical door closers and uring WWII, Weihrauch was the only German factory to continue production of spare parts for bicycles.
Split into simpler sentences: In 1928, Weihrauch began international sale of bicycle parts and mechanical door closers. During WWII, Weihrauch was the only German factory to continue production of spare parts for bicycles.