This bike has been a neat one to figure out. We are going with 1991 since many of the parts date code as 1991 but it could easily be 1992 as well.  The frame is beautifully made with very nice fillet brazing work but then it has mid-level parts on it.  The 500 CX crank with 30/40/50 rings was also a little strange but was likely added to make up for the 24" wheels.  The front derailleur has also been lengthened to more closely follow the chain rings. The first thought was some type of trials bike with the 24" wheels and 15.5" tall bottom bracket but that didn't fit with the gearing.  A call to Rocky Mountain resulted in some head scratching until they contacted one of there long time builders who remembered the bike.  It was designed to be a courier bike and originally had some swinging pedal extensions on it which explained the tall bottom bracket.  Apparently, the extensions were removed somewhere along the line.  If anyone has any more information, please let us know and we will post up any additions.

UPDATE:  Talked to some more folks at Rocky Mountain and gleaned a few more details.  The bike was built around a swinging crank extension made by Ralph Lewis of South Africa.  Still don't have a set of the extensions but I did add a photo of Paula Newby-Fraser using a set on her tri bike.