Originally Posted by
elTwitcho
I'd have to assume there is a 5th bolt as otherwise it'd have to be an extremely bizarre proprietary ring design that wouldn't make a ton of sense. Having the bolt behind the arm is a bit of a pain in the ass but no big deal IMO
you dont need a proprietary ring...
the bolt is long and threads into the crank from the back and there is a spacer between the chainring and crank. its not rocket science, or new technology.
whats a pain about it? its just one chainring bolt that doesn't require a nut or any tool to hold it...
edit:
early campy cranks with the hidden bolt did have a "half spider arm" behind the crank and the nut was pressed into the large chainring. this did use a special chainring but you could use a standard chainring and nut if you wanted to. (ive done it)