time calcutation for biking route seems totally unreasonable

Issue

The calcutation of time for a biking route seems to be totally unreasonable in osm.org.

Here it is said: "If your issue relates to the demo site or openstreetmap.org behaviour, please check these profiles first to see if they explain the behaviour before creating an issue here." I not even have an idea, what is meant! I'd suggest, if this project wants help, please sample all feedback in one place and let knowlegable people decide, how to route it to the specific sub-projects.

Steps to reproduce

See here for an example, estimated is 13 minutes for 10 km

Link to Example

If we assume a generic speed for a biker to be 20 km/h (which seems to be pretty fast for me) than 10 km would be half an hour, not 13 minutes.

Specifications

No development, just bug report.