i know some tracks in boomers reserve DH danny and i ride them all of the time there is a killer berm dug up out of a dam near my house and there is a couple of really steep hills.
Are you talking about the one which afterwards throws you out into a clearing before heading down to a creek crossing? Good fun that one. Waldog and I took some pics there
one day
After crossing that creek, we climb up a little on the other side, before hitting single track all the way to the 5-ways incorporating Long Gully Rd (as mentioned above, you pass a great big puddle). From here if you turn hard left up Broadacres Rd there is singletrack at first through the pines on the left, then crossing left to right side of road all the way to Clintons. Head East on Clintons, singletrack on right side of road, past the Equestrian centre, then ST crosses to left side of road, then onto the road itself up to the corner of Clintons & Rob Roy. Get some speed up as you approach, be careful of cars coming around the corner, and hit the little climb up onto the embankment on the inside of the corner, past the dog skull, and follow this awesome bit of ST (we call the Motchalls Descent) all the way down to Motchalls Rd proper.
From here, right takes you back to 5-Ways where you can hit up the Bunjil trails (which are best done above when you first get to 5-ways), and left takes you to the Gills Rd track down to E-YG road, which can take you to Rob Roy trails (awesome), and the infamous Ridge Rd track (awesomer).
Ridge Rd & Motchalls are 2 of my favourite bits of trails in Melbourne for hammering downhill.
Miles & miles of both bushland ST and roadside ST all around these parts. Many ways of incorporating it all into tailor made loops of varying levels of difficulty.
I have ridden, but do not remember the details of, trails heading all the way to Yarra Ridge & back. Some guys on the MTBR forum I mentioned above are trying to incorporate a link to Warrandyte, and another to Greensborough.
Best bet is to hang out in that forum and see what develops.