[SgtBaxter]

Do either of these resorts allow mountain biking during the summer months?

I've read somewhere before that they do but can't find any info on their websites.

 

[Bigrocks]

No. However, the idea is discussed regularly on forums.
Yamba Forums • View topic - Ski Roundtop

The same company owns Whitetail(which used to have lift served riding years ago),Liberty and Roundtop. Whitetail was sued about ten years ago and that ended mtbing there, with the exception of a DH race there in 2006.