For fell/trail/orienteering the Silva Trail Runner is a great piece of kit. I ran all last winter with one.
It''s fairly light, and feels really stable. It has a separate wide beam which makes it easier to see
where you're putting your feet, and spot path junctions/controls that you might otherwise pass.
Think you would need something else on the bike.
. Its quite heavy at 280g with lithium batteries, but it is amazing. We have an 11:30 start time so I am considering taking it. The light comes with a bike, helmet and head mounting kit. The headstrap is quite uncomfortable, I contacted hope and they are in the process of redesigning it. At £80 its not that bad.