I wouldn't ride without one. Wouldn't suggest anyone ride without one on the street. It HAS however been done by some folks. Good idea? Probably not. That being said if you buy a set of Mavic Ellipse wheels...the newer Mavic set....order the lockring with them cause they do not come with one. Is this stupid for Mavic to sell em with out one?.....yes. Is the lockring a french thread?.....yes. Do the 2 people who I know who bought them want to ride them without a lockring?...yes. Take yer chances.