The descent for this ride we discovered a few weeks ago, however we realised there was a much more direct route to the beginning rather than going all the way to the top of St. Eynard (an extra 500m climb).
A gentle climb up from La Tronche through Corenc to the top of the Col de Vence gives an easy ascent, save for the last 100m which is a sharp offroad unrideable section.
Most of the route viewed from the road up; the start is basically a traverse across (what looks like from this view) a cliff with a little bit of hike-a-bike for good measure, then onto a ridge-line descent which then disappears over the back of the hill and down into Meylan.
This is the view back down to the first photo and is where you cut off the main path onto a pretty unassuming little track that traverses across the hill, its rideable but is also something you dont want to slip off the side of as you might not stop sliding!
The descent starts on a bit of a ridge which is pretty cool, it is quite steep and exposed away down to either side though, you don’t really want to be riding off the edge of the track as its a long way down unless you manage to catch yourself in some trees to stop you! The top of the ridge is wide enough to feel safe however.
The descent is completely on singletrack like the above photos, twisting and turning in and out of street, I think there is only one or two short straight bits, the rest works its way in and out of holes, rocks, trees and drops which makes for an awesome descent. It has clearly been built for bikers as no walkers trail would have so many corners! But there must be another 20 or so trails leading off at various stages that flash past you (these are ont the list to be explored! I am sure I could spend a day up there and not ride the same one twice). The last photo here is only about half way down as you just don’t want to stop once you get into the flow of the trail, maybe one time I will be able to stop myself and take a few photos of the singeltrack holyness….