"Tell me the size of the those two biggees at the bottom. I have a Keygos M12, so-call-rated at 1600 lum, and takes a 26650, it can work with a 18650 too. However, the diameter of this baby can't work in that open clip.. It needs the ones like you have on those two at the bottom, which I have already ordered."

Do you mean the flashlights or the mounts?

The light on the left is a Solarforce M8, which can run on 1x or 2x 18650, which is why I bought it. I haven't actually had a chance to use it on the bike yet, as it's the middle of winter in Chicago - maybe in early Spring when weather improves. The M8 uses an XM-L T6 LED, is a fairly expensive light and is a thrower, but it puts out about 800 lumens on high, a little more with 2 cells in, but that's too long for the bike. In the picture it's strapped into a Twofish Cycloblock, which is a beafier verison of the lockblock and will handle larger lights without as much bounce. Size of the M8 in 1x version is just slightly larger than your Keygos, but it has a much larger head diameter. The light on the right (copper colored) is an old C8 from Baja Designs, has a SSC P7 LED, probably puts out 550 lumens on high, with good run time and a nice warm flood. It should be the same size as your Keygos. I've got it strapped into a standard Twofish lockblock. Fake versions of these can also be had from DX for around $2.

By the way, not to burst your bubble or anything, but almost all of the claimed lumens on those lights on fleabay, DX and DD are bogus. The max theoretical lumens off a hard driven XM-L emitter is ~ 900. Your typical light is never driven that hard and they end up being 700 or so, up to probably 800 off the front lumens. They still work fine for bike though!

The best lights in my collection for helmet use are the P-Rocket and the N-Light ST50. Both have great throw and are 700-750 lumens.

I love the look of your Keygos lights. There have been mixed reviews on them at BLF, but they still seem like solid lights for a great price.