In June 2018 I acquired a Fenix BC21R Rechargeable Bike Light to use for Expedition Oregon, an expedition length adventure race. In total Quest Race Team raced for over 61 hours. During this race I used two Fenix lights, the BC21R Bike Light and the HL60R Headlamp. On this review I am focusing on the BC21R. During the race we traveled on bike in the dark for almost 14 hours. The BC21R was plenty of light for riding on gravel roads and non-technical trails. Once the trails got technical I opted for a headlamp as well as the handlebar light in order to have better vision around corners.
The BC21R is durable and has a quick mounting system which allows easy transition between different bikes, however the rubber band that attaches the light to the handlebar seems like it might fail sooner than other mounting systems. That being said I have used it for lots of hours of mountain biking and had no issues with it falling off. I would recommend this light for mountain biking as well as riding around town.