I walk dogs and bike up there. The dog truffle problem is bad, as well as general rubbish on the hill and I think this is a general problem of ignorance and apathy in the wider sense…
Biking up there – I have never had an issue, but try and not skid etc, when off the “main paths”, take it easy on the blind descents on the south side, and slow down for dogs etc… Generally be a courteous rider
I note that the Ranger has written in the Friends of Corstorphine Hill newsletter about his efforts to reduce this “distructive behaviour”, maybe some bridges to be built here? It’s everyone’s hill afterall.
http://www.corstorphinehill.org.uk/newsletters/newsletter33.pdf