>>124593790s mtb geometry was closer to road bike geometry than modern mtb geometry, so if you fit it with slick tires you get a fast bike that is fairly well adjusted to urban setting but also to gravel and light off road use for very cheap money. If you max out aero riding position and gears you will almost be as fast as a road bike. Your bike will still be a few kg heavier than a road bike and have different riding characteristics due to 26", though.
