There’s a few techniques used locally to deal with the bike ban. You can ignore it, you can give up on the mountain bike, you can stick to the man-made trails and you can go elsewhere. You can also have a look at the Arrete du Maire, try and find a loophole, and hope for the best.
The arrete lists 12 exceptions to the July & August bike ban, most of which are listed in the official Chamonix bike map (which you can also get a paper copy from the tourist info and bike shops around town) but there’s 2 in particular which aren’t.
So, armed with a paper print out of the arrete should I stumble across any gendarmes, I headed up Brevant and dropped into the “Couloir du Brevant”. There’s a few trails down from the Brevant lifts via the couloir, Sentier des Gardes probably being the best of the permitted ways (bikes are completely banned from the national park that the trails from the top lift pass) however the path leaves the couloir, so instead I stayed on the tech rocky singletrack all the way down. Verdict? A nice change from the man-made tracks in the valley, I didn’t get arrested and all the walkers I met were very friendly, but you do feel like you’re missing the best riding.
A couple of evenings later Rob & I headed up by the Montenvers railway to test the grey areas further. The arrete lists “sortie de la VALLEE BLANCHE” as a green light for bikes. The infamous James Bond track, a 4×4 path used both to access the Roches de Mottets buvette and as a descent into Chamonix from the Vallee Blanche ski in winter, is probably what was meant but I’ve sortied from the Vallee Blanche a lot of ways, so….
We headed up to Chalet Caillet at a relaxed pace, passing a few walkers in the opposite direction and hoping to let the last few descend the path before we started. Whilst the climb up to the chalet is mostly on 4×4 track, the descent is pure singletrack, and one of the best circular loops in the valley.
If you want to give the Caillet a go, and it’s completely at your own risk if you do, definitely go either before the Montenvers railway opens or leave it till the evening. The descent track isn’t wide and much better if you’re not stopping every 20 meters. It’s a popular walk and in the middle of the day that’s also what you’ll be doing.
And if you get caught and the “but officer, this IS a descent from the Vallee Blanche” argument doesn’t work, don’t blame me!