Update weighting.md

Author: karussell

docs/core/weighting.md

@@ -5,7 +5,8 @@ In order to create a custom Weighting you need to do the following:
  1. implement the Weighting class
  2. create a subclass of GraphHopper and overwrite createWeighting where you return a new instance of your custom weighting if e.g. the string 'customweighting' is specified. Otherwise let the super class handle it.
 
-See AvoidEdgesWeighting for an example of a weighting which avoids certain edges (i.e. returns infinity weight)
+See AvoidEdgesWeighting for an example of a weighting which avoids certain edges (i.e. returns infinity weight). 
+If your blocking edges change per-request you need to disable the speed mode e.g. via `ch.disable=true` as URL or Java hints parameter.
 
 Now you need to create your custom GraphHopper:
 
@@ -36,5 +37,3 @@ class MyGraphHopper extends GraphHopper {
 
 For `forbiddenEdges` you need to determine the edges from some GPS coordinates. 
 Have a look into the [location index docs](./location-index.md). 
-
-If your blocking edges change per-request you need to disable the speed mode e.g. via `prepare.ch.weightings=no`