Hi, I am looking to buy a good cheap bycicle flashlight to use for riding my bike in unlit area. Ideally, the flashlight should be cheap, and either attach to a road or mountain bike. My requirements are a long runtime (sustainable ) combined with good brightness.
My take - Offbondage. Crazy name but it’s a cheap and fairly bright light with decent size battery, not only tat it also has anti-glare optics with a cutoff line so you can use it in the city and you won;t blind other people.
I bought one of those holders that you show but never use it because there is a simpler version of the 18650 flashlight holder. They used to be available from China for just a buck but now if you live in the US it makes much more sense to buy from a US seller on eBay. I’ve used the combination of the “360 degree flashlight holder”, a quality NCR/Panasonic 3,400 mAh 18650 battery, and an XML-T6 LED flashlight for my bike lights. Output is about 900 lumens. The flashlight is focusable so you can set your beam to the desired width. The holder allows you to aim the beam exactly where you want it to go. The holder was designed specifically for this type of flashlight so it never comes loose but is easily clipped in and out.
Lots of sources for the flashlight like this one for $9 on eBay Adjustable Focus Zoom Cree Xml-t6 Led 1200lm Waterproof Flashlight Torch 3-modes | eBay
flashlight holder $6 360 Degree Bike LED Flashlight Mount Holder Lamp Stand Bicycle Torch Clip Clamp | eBay If you buy more than one from other sellers, the unit price goes down a lot (3 for $9.49) 360 ° Degree Universal Flashlight Clamp Bike Rotating Flashlight Holder Bracket | eBay
You can use any 18650 battery but the name brands like NCR or Samsung last a lot longer than the cheaper Chinese made batteries.
Here is the flashlight mounted on a trike but it works the same on my mountain bike handlebars https://i.postimg.cc/59LT752W/flashlight-mounted-on-trike.png
I just checked ali express and B01 cheapest is around $45. It looks like a convoy C8 size host with a different reflector which I guess gives a square beam.