Never had any problem in Les Houches, it’s not as “cosmo” as Cham therefore a little bit more laid back. google the local tourist office and download the info booklet – they actively encourage biking on the official tracks.There is now a DH track from the Bellevue lift but the traverse halfway down was a real bog slog last year!
the best tracks are GR5 from bellevue lift which can get busy with walkers and and is very technical and Kandahar from the Parion lift which is usually very quiet albeit both are a bit “cheeky”.
guess it depends on your preferred type of riding.
Hope this helps
