I swear I have seen it on this very forum, but cannot find the thread, but is it possible to simply remove the disc brake fro ma front mtb wheel and bolt on a cog?...therefore creating a fixed wheel? What else would need to be done to it? EDIT: Done some more research so some more questions: 1. Will a bolt on cassette cog fit to any brake disc mount? If not then how can I check these are compatible? 2. Can the brake disc mount be moved along the hub with spacers to get a better chainline? 3. What is the standard spacing of a front mtb hub and the rear of an "older" steel bike?....if the modern spacings of the mtb hubs are more than the spacings of the newer bikes then am I knackered? 4. What bolt on cassette cogs can I use? Or is drilling one going to be cheaper Anything I haven't thought about?