I recently ordered an Astrolux S1 for cycling, but I’m very envious of this lens for the Convoy S2 (10197 Carclo Lens - Elliptical Spot LED Optic). I do like this oblong shape.
Will this lens fit the Astrolux S1, or do I have to find something else?
Thanks for helping out.
The S2 lens is 20.5mm in diameter
You won`t use 20mm tir in S2/A6/etc. if you don`t want to lose 20-30% of luminous flux.
Much better to find out a 16mm tir.
To me 0.5mm isn’t a huge difference. Will it fit too loosely or lack a proper seal of some variety?
From what I understand, I’m looking for something that gives off good flood, without any major central throw beam. I have had no real success finding anything suitable, could you suggest something?
Thanks for the help.
Could you please explain this? this is relevant to my interests
It is hard to explain in foreign language…
Narrow optics or reflectors are using their widest parts for hotspot. Take smth like C8 and close central of the glass with any coin. There will be no difference in hotspot at all.
There is the same effect when using wide/floody/elliptic optics with the only difference: they use edges not for hotspot only, but for hole spot.
So if you take up an 20mm optics (by the way it is made for using with holder) and put it in the flashlight with 17mm bezel hole for light transmition you will lost lots of luminous flux. (17^3/20^3=61.4%)
ohhh I understand you. Thanks! 
TS, try to use some from the ledil: FA11200, CA11052, CP12680.
Maybe there is also something suitable from ledlink, I’ll check later.
I also got my lights for (road) biking. Well, I checked this review at youtube of the Astrolux and the flashlight and beam looks a lot like the Convoy S2+. I think it’s as floody as it gets for a light that can take a 18650. Personally I think that it’s plenty flood for biking, but if you want to try that lens, .5mm shouldn’t be an issue. But of course, if you’re gonna lose output as kiriba-ru said, you may want to try something like a zoomie. That’s what I initially thought would be the way to go but never liked it on the bike. It doesn’t light much farther than a few meters.
My favorite bike light is now a modded Ultrafire F15 with a 3A driver, noctigon U4 emitter and an OP reflector I got to replace the original one. It’s super bright, lasts over 2 hours on a 26650 battery and the beam is a great combo of flood and throw for my taste.
Post #6 edited, hope this`ll make everyone understand me better.
TS, LEDLINK LL01CR-HQ2545L-M2 can be also a good choice.
Thank you very much for the detailed explanation. I think I’ll stick with the regular lens, and get a different one if I feel like it can be improved. In the end, I won’t run it at full capacity when riding, so a 30-40% loss isn’t that bad, but you are correct that 16mm TIR will be the best solution.
but for shaped beams…
These are highly efficient optics.
I’ve never been a fan of TIR as a cyclist because they are bright in a very narrow beam. Okay in my blinkies but not my main being-seen lights. My seeing light is on my helmet so I see what I look at.
For a general headlight, the cheap Chinese original design lights have a $6 optional lens that works similar to the one in the OP.
They do work and at 900-someodd lumens, loss isn’t an issue.
