Answer Question
A helmet light should be at least 700 lumens to get good night vision while mountain biking on single track. So a good light for the Troy Lee A1 or A2 helmets that isn't too expensive would be the NiteRider Lumina 750 Boost light, along with the NiteRider Lumina Helmet Mount Strap.
For a bit more brightness on the trail go with the NiteRider Lumina 950 Boost light.
In addition to this, pair your helmet light up with a handle bar light like the NiteRider Lumina Micro 600 Bike Light for the great night vision riding.
What size socket do I need to service my Fox 36 Forks?
What are the best mountain biking Knee Pads?
What's the best Gimbal to use for filming mountain biking?
What grease should I use to service Crank Brothers Stamp pedals?
What are your favorite grips for mountain biking?
What are the Largest Mountain Bike Flat Pedals?
What are some of the best full face DH mountain biking helmets?
Why is my chain slightly catching on Shimano XTR 12 speed Rear Cassette?