Trails in SA outside Adelaide

[jofeses]

Hi,

just wondering if anyone has ridden anywhere on the Eyre Peninsula,
i spend half the year and Adelaide half on the Eyre Peninsula,
I understand there won't be any purpose built trails, just curious if anyone has stumbled across some enjoyable ones

Also this hunt for trails raises the question, is it legal to ride walking paths in national parks?
Where i live i am surrounded by national parks but have been hesitant to ride there as i am not sure on the rules regarding bikes.

Any advice/help would be appreciated

cheers