Originally Posted by elTwitcho

Yeah it was the strangest thing. I got them loosened with an allen key but then the backing would just spin freely so I needed a tool to hold the backing in place while I unscrewed the nut. I picked up a park tool chainring tool for that and neither end would fit properly. At the shop they tried a couple tools and said they'd just have to drill it. It's odd because the bolts were stock and Urbane assembled the bike, so they certainly weren't the wrong bolt size...