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    I've never seen an official IMBA rating on a sign.<br>
    I see both mtb:scale and mtb:scale:imba both used.   The wiki for
    mtb:scale doesn't make sense.   It's either skewed for extremely
    extreme riding or they don't understand gradient.   It says that for
    mtb:scale=1, gradient<40%.   This is meaningless.   Nobody can
    ride up an unpaved grade that is 40%, or probably even 30%.   A
    steep trail is 15%.   A really steep, almost unrideable, very
    difficult hiking, trail is 20%.    Going downhill, anything above
    25% is a double black, only a small percentage of riders can ride,
    unless it is very smooth with really good traction.   <br>
    <br>
    The tag has been used with common sense, but inconsistently, instead
    of the wiki definition.   <br>
    <br>
    In the US, we us a green/blue/black/doubleBlack system which I would
    not consider an IMBA system, but merely a subjective rating by
    whoever made the map,  usually a local mtb club or land manager.  
    IMBA probably clarified it, but it probably predates IMBA.   The
    apps trailforks and mtbproject use green/blue/black/doubleBlack
    ratings as determined by the users.  For the most part it's
    consistent, but one does have to be cognizant of the local bias. <br>
    The imba rating system was not invented for bike parks, so the OSM
    use for bike parks doesn't make much sense.<br>
    <br>
    In my opinion, mtb:scale:imba could be deprecated, and the wiki for
    mtb:scale updated & clarified.    <br>
    <br>
    <div class="moz-cite-prefix">On 4/22/20 5:00 AM, Simon Poole wrote:<br>
    </div>
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      cite="mid:9a241c00-8be2-975c-ff0f-d6a2dfb453ef@poole.ch">
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      <p>IMHO, the problem is using <a
          href="https://wiki.openstreetmap.org/wiki/Talk:Key:mtb:scale:imba"
          target="_blank" moz-do-not-send="true">mtb:scale:imba</a> in
        place of mtb:scale for normal trails which I suspect the intent
        of the original wording was to avoid that happening.</p>
      <p>Simon<br>
      </p>
      <div class="moz-cite-prefix">Am 22.04.2020 um 10:53 schrieb Andrew
        Harvey:<br>
      </div>
      <blockquote type="cite"
cite="mid:CAD5VjsuQD8fC4WxWkXwXKN-XVtw3hdCNauKgf1-HzmDOx62JQw@mail.gmail.com">
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        <div dir="ltr">I've been using mtb:scale:imba on any kind of
          trail where signage at the site notes an IMBA rating, in this
          way it's verifiable based on the sign. I don't know what
          "bikepark" and "north shore" mean here but while some of these
          trails which have an IMBA rating can be consider together as
          part of a collection of trails and that collection does have a
          name sperate to the individual tracks (which I guess is what
          bikepark means) others which do have signposted IMBA ratings
          are standalone and not part of a named collection of trails.
          <div><br>
          </div>
          <div>So if it has an official or signposted IMBA rating, it
            should be tagged regardless of the trail being "natural" or
            with "artificial obstacles" and regardless if it's part of a
            mountain bike "park" or not.</div>
        </div>
        <br>
        <div class="gmail_quote">
          <div dir="ltr" class="gmail_attr">On Wed, 22 Apr 2020 at
            17:29, Joseph Eisenberg <<a
              href="mailto:joseph.eisenberg@gmail.com"
              moz-do-not-send="true">joseph.eisenberg@gmail.com</a>>
            wrote:<br>
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                  <div dir="ltr">
                    <div dir="ltr">
                      <div dir="ltr">Another user would like to
                        redefine the definition of "Key:mtb:scale:imba" </div>
                      <div dir="ltr"><br>
                      </div>
                      <div>See suggestions at <a
                          href="https://wiki.openstreetmap.org/wiki/Talk:Key:mtb:scale:imba"
                          target="_blank" moz-do-not-send="true">https://wiki.openstreetmap.org/wiki/Talk:Key:mtb:scale:imba</a>:</div>
                      <div><br>
                      </div>
                      <div>This tag was approved in the proposal <a
                          href="https://wiki.openstreetmap.org/wiki/Proposed_features/mtb:scale"
                          target="_blank" moz-do-not-send="true">https://wiki.openstreetmap.org/wiki/Proposed_features/mtb:scale</a>
                        - with the description "The IMBA Trail
                        Difficulty Rating System shall be used for
                        bikeparks. Especially for North Shore. It is
                        adapted to mtb trails with artificial obstacles.
                        For "natural" trails it is advised to use the
                        mtb:scale/mtb:uphill:scale." - linked to <a
href="http://www.imba.com/resources/trail_building/itn_17_4_trail_difficulty.html"
                          target="_blank" moz-do-not-send="true">http://www.imba.com/resources/trail_building/itn_17_4_trail_difficulty.html</a></div>
                      <div><br>
                      </div>
                      <div>Can other mappers who use this tag frequently
                        confirm whether it is limited to specifically
                        designed and built bike trails, like those found
                        in "bikeparks"?</div>
                      <div><br>
                      </div>
                      <div>-- Joseph Eisenberg</div>
                    </div>
                  </div>
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              </div>
            </div>
            _______________________________________________<br>
            Tagging mailing list<br>
            <a href="mailto:Tagging@openstreetmap.org" target="_blank"
              moz-do-not-send="true">Tagging@openstreetmap.org</a><br>
            <a href="https://lists.openstreetmap.org/listinfo/tagging"
              rel="noreferrer" target="_blank" moz-do-not-send="true">https://lists.openstreetmap.org/listinfo/tagging</a><br>
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        <pre class="moz-quote-pre" wrap="">_______________________________________________
Tagging mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Tagging@openstreetmap.org" moz-do-not-send="true">Tagging@openstreetmap.org</a>
<a class="moz-txt-link-freetext" href="https://lists.openstreetmap.org/listinfo/tagging" moz-do-not-send="true">https://lists.openstreetmap.org/listinfo/tagging</a>
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      <pre class="moz-quote-pre" wrap="">_______________________________________________
Tagging mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Tagging@openstreetmap.org">Tagging@openstreetmap.org</a>
<a class="moz-txt-link-freetext" href="https://lists.openstreetmap.org/listinfo/tagging">https://lists.openstreetmap.org/listinfo/tagging</a>
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