Where is a good spot to go camping in Canberra that is near mountain biking trails?

The ACT has some national parks but you will find that the close by New South Wales ones are More likely to be what you are after. They are not far and there are many that have great mountain bike riding. You could try the Brindabellas and pf course the Snowy Mountains. Thredbo is well catered for mountain bikers. But check out National Parks and Wildlife sites for info as some places may have restrictions on where you can and can't mountain bike. A good tip is to check out mountain bike and camping stores they usually have some good advice that they don't mind sharing.