There are several webcams along the route of the 3 Pistes Cycle.
Here are links to a few of them. Click on image for live feed.
Glenshee Ski Centre Panorama
Braemar Snowgates webcam
River Don at Strathdon A939
The Lecht Panorama
CairnGorm Mountain Day Lodge
Finally here is a weather station at Nethy Bridge, near to the final feed station. http://monadh.com/nbl.php