Mountain Bike Light Follow-up

It's been 2 years since my last mountain bike light post, so I thought a follow-up on mountain bike lights would be useful.

I've still been running the 1200 lumen Magic Shine clone mounted on the handle bars. It's still bright, holds about the same charge as new, and I haven't had any problems with it. That said, I don't night ride a lot so the light hasn't had extensive use. Still, for the price these days, it's a very good light.

The new addition is the UltraFire WF-501B.
UltraFire WF-501B XM-LT6 5-Mode 510-Lumen White LED Flashlight with Strap (1*18650)
This flashlight puts out a lot of light in a nice sized spot with soft edges. The stated lumens is 510, but as with all these flashlights you don't really get that much light, but it's much brighter than the TR-801 (350 stated lumens) I had been using on my helmet. The TR-801 was hardly visible when the 1200 lumen bar light was on high, the WF-501B lights up the areas outside the spot of the 1200 lumen light. This is handy for corners, dips and quick rises.

I was concerned the WF-501B wouldn't run as long as the old TR-801. They both take the same size battery (18650), and even though the efficiency of LEDs keeps improving, it takes power to make light. I tested the light output of the WF-501B on high with a freshly charged battery and compared it to the TR-801:

The WF-501B initially puts out approximately 3 times as much light as the TR-801, but after 40 minutes it is down to double. I believe this is due to the WB-501B getting hot and running less efficiently. I ran this test at room temperature so you may get more light output in cold temperatures and/or if you have air flowing over the flashlight to remove heat. The WB-501B ran 100 minutes before the light output drops rapidly. Frankly I was surprised to get this much run-time given the double light output. Most of my rides are under 2 hours, and I often switch down to medium or low for climbing so this flashlight has worked well for me. I carry a spare battery but haven't had to swap batteries yet.

Concerned about heat, I wrapped the P60 LED sub-assembly in aluminum foil to improve heat transfer into the body. It seemed to help. I haven't noticed the light getting too hot mounted on my helmet on cool nights.

I chose the 5-mode version for the 3 output levels (high, medium, low), even though the SOS and strobe modes are annoying. It's going for $9.30 these days. There are other variations available (the 2 mode might be nice - high, low).

The WB-501B was a good upgrade. It's cheap, bright, has a good spot size for mountain biking and it runs long enough for my rides. Recommended.