There’s some great mountain biking in the Chilterns with lots of bridleways criss-crossing the steep, chalky terrain; not to mention the many purpose built downhill trails and the cross-country route at Aston Hill.
Way back in issue 14 of the popular online magazine IMBikemag, they featured a trail guide to the Chilterns. The 12.5 mile mountain bike route starts at the top of Whiteleaf Hill just outside Princes Risborough and meanders across the Chilterns on a variety of bridleways and tracks including areas of Coombe Hill.
Luckily for us they also produced a video of the route and got some fantastic action shots. The full article, trail guide, video and gpx download is on their website.