Olight M21 - IDEAS TO MOD? - Old SST-50 LED Inside -

Hi Everyone.

I have a like new Olight M21 with the older SST–50 LED in it.

I love the feel of this light along with its rear clicky…

Anyone Mod one of these tight fixed heads?

Should I just leave it alone or can it be Modded properly?

I really do like the light tint and such but for some reason This light isn’t putting out too well. The spill could be better with a bit more power under the hood.

Thanks for any suggestions…. =)

Welcome to BLF! If it has a SST-50 in it then the easiest thing to do would be a driver swap of some kind. Can the head be taken off of it?

Welcome to the madness, Lightstride!

It appears the head is like vaccuum sealed or something.

From inside, its seamless. The outside, the glass appears “Fixed”.

I may be wrong…

I will do another long hard look… =[

Thanks for the welcomes too guys. I am new and after a 3year affair with stock lights, I am now venturing into doing a mod or two and/or having a few done for me. =)

I’ll get back to yah…
. - John

thats funny. ive been meaning to ask this exact question here on the forums but just never got around to it, and now someone with the same light feels the same way.

but i think i got even the older model….olight m20s the one with the secondary side switch for instant strobe. with a xpg s2 reflector.
you can purchase a xml led swap but ive seen comparison videos, and its not much of a difference. so i never went that route.
so does anybody know if theres anything we can do with our lights? i have never done any mods but is very willing to try, i absolutely love this light, but just needs to pump out a lil more juice.

I found out how to get the head off…

(( I can’t figure out how to post my pics on here quite yet but will once I do.))

The head appears seamless, but with a large crecent wrench and twisting the head, it finally came loose. I took out the reflector and exposed the led.

Two small holes in it, I used my tool for that kind of thing and twisted slightly.

BIG MISTAKE. Broke one of the Led leads. It had nothing but white paste for heat transfer underneath while not being screwed on or anything. The paste and the reflector being pressed against it is what keeps it in place.

NOW, the wires feed through a hole into another segment of the head which must come off somehow. I see how, but have to honestly figure it out.


I’ll take a stab at it the next few days, unless anyone here has the answer.

I DOVE IN headfirst here and made a big mistake within minutes. Delicate hands is my goal. Anyhow, I’d like to try a XM-L U2 LED in there. I already have 3 T6’s. Also, I imagine heat dissipation will be an issue over 500-600 lumens, so that alone is a motivator.

The LED platform is 15mm Round. I have no idea of the driver for inside. I see alot of 105 Drivers being mentioned driving the XM-L T6 and U2. Hope it would fit. I really like the light color of the SST-50, but after my Sunwayman (1) RCR123 EDC V10R kicked its butt on Turbo; ITS TIME FOR AN OVERHAUL!!!

Hey Blue ——, a LED swap is only part of the equation.

I’d imagine the Electronic engine is the MAJOR part of any mod.

I do RC cars and the Electronic Speed Control is the Key to how the motor performs.

I’m new to all this, but I think I understand. Am I right here??

Welcome Lightstride,you didn't screw up,no worries many of us modders have done this it's called the price of education.I have gotten to finishing a mod and crushed an emitter screwing in a reflector so don't feel bad.I haven't done this particular light,but if you have questions,this forum is more than helpful.

There are few SST-50 lights that I’ve seen that couldn’t be improved with a swap to XM-L.

You’re on the right track; you may even be able to re-use the stock driver to power the XM-L U2 with longer runtimes and greater output…

If the stock driver can push this light another 100 - 150 lumens, I’d leave it well enough alone. :slight_smile:

I could just swap it and see what happens…

Thanks for the suggestion.

Scratching my head a bit…

The price for a SST-50 Emitter is almost 4X that of an XM-L U2!!

I like the color of the SST. So, if I want that color, but just a bit more…

…Then Ill have to deal with the DRIVER! :slight_smile:

MAY GO THAT ROUTE. I’ll buy a xm-l U2 emitter just in case the SST-50 runs a bit warmer than comfortable on high… I’m thinkin.

Ill post a few pics soon…(( Finally figured it out! ))

In the process of revamping my Olight M21, I’ve learned something quite nice.


I bought some high end parachute cord awhile back. I made some simple and functional embellishments that have helped renew my affection for a light than could have “MORE”.

One thing I like Olight is their knurling and rear clicky. Both are top notch and feel better in the hand than almost any light I’ve ever handled. Also, this is the VERY FIRST tactical light I ever bought.

I also replaced the rear clicky with a white/flourecent one. Different look and sense about it is enought to chase away some familiarity enough to renew my interest.

I’ll post a few pics within a few days…

Follow this 5 easy steps

1. unscrew the ss bezel

2. remove the reflector

3. remove the black plastic with a pointed tweezer

4. de-solder the sst-50 led

5. solder a xm-l u2 led ( put some thermal paste )

Better performance in lumens after changing the 50 to the U2?¿

I think yes, but I want your confirmation. Also I guess, it now has better throw…. or I am wrong?¿

After changing to xm-l u2, throw hasn’t improved much but it is definitely much brighter.

can someone tell me how can i upload photos?