I only ride a road bike, but maybe this will be useful to you or others in my shoes. I work nights and started bike commuting earlier this year. I bought a Nite Rider Trail Rat (about $100, can be adapted to go on either the handlebars or the helmet) and I've been very satisfied with it. Some of the streets I ride home are pitch black and it produces enough light for me to stay at about 15 mph and see clearly. I decided on the handlebar mount because I'm using to car headlights with a forward-looking field of vision. My LBS owner loved the Nite Rider products and other riders who I talked to before buying also recommended them.