I wonder if someone knows a way to calculate time-cost isochrones in a bike road network layer, taking the slope into consideration.
The GRASS tool "v.net.iso" allows to create a line-vector layer with categories depending of how far the roads are from a determinated point. Having the data about the speed allowed me to do the analisys with time-cost categories.
But I would like the analisys to show how slope affects the isochrones: It doesn´t take the same time cycling towards the top of a hill than getting down. So taking the slope into consideration would make the analysis more attached to the reality.