bicycle trail type & nature

Today bicycle trails are all marked as blue (in the opencyclemap)
I would like to suggest the following method in order to give the riders info on the type of trail:

  • color purple or magenta for paved trails or trails that do not require MTB skill
  • color green for trails that require basic MTB skill
  • color blue for trails that require medium MTB skill
  • color Black for trails that require advanced MTB skill
    (This mathod is used on bicycle maps in Israel)
    This method will give a clear picture as for the nature of each trail (or each part of a certain trail) and will enhance the use of opencyclemap

This is not really the right forum for your question, as it has nothing to do with the editors for OSM. Your question is about rendering OSM data.
Since you are interested in MTB, you might have a look at http://openmtbmap.org/ . They create dedicated Garmin maps for MTB