The HMBA trailers do have crank holders, but we have lined the inside of the holder with poly pipe, so they are not as bitey as the CORC trailers, there is no metal to crank contact, I slip a bit of DH inner tube over the crank arm to protect it.
The trails are part of the 24 hour track, I know that alot of people did them as there first race and had a ball on them. One track has a small rock garden that has a B line around it. Another has a few tight switch backs, there are no drops or steep rutted bits. There is lots of off camber corners at the moment but it depends how many people we get to the working bee we might be able to reduce the amount but we can't get rid of all of them because it is not a BMX track.
These tracks were designed by Ross Cairns, who is a avid full rigid single speeder freak, so that is what the tracks are designed around. I have ridden them on my full rigid 29er but the most fun was on my Yeti 575, (but Yeti's are the most fun bikes to ride anyway, heaps better than Advanti's). If love the Roller Coaster at Ourimbah or skids for kids at Awaba you'll love these tracks.