Lezyne's Femto Drive rear LED is a neat little 'emergency be seen' light combining a machined alloy body and versatile bracket that fits to seatpins, clothes, bags, anything you can think of really that can be attached to with either a band fitting or a clip.
The overall length is only 25mm and comes in a range of anodised colours which do look pretty cool on your bike. The Femto is easy to fit and remove in seconds which makes it ideal for bikes that are locked up in public.
The lens itself is the button, ideal if you need to turn it on or off with thick winter gloves on. Push and hold to turn on and you get a choice of five modes ranging from constant through various flashing modes and one which they call 'orbing' where the light fades before going back to full without actually going off.
Burn times are pretty good with 30 hours for constant and 60 for the others from two CR2032 watch style batteries. In testing though I'd change the batteries a good ten hours before that as unlike rechargeable lithium batteries these fade as they start to run out.
The Femto is classed as water resistant and there were no real issues with moisture getting in. On one very soggy ride without mudguards the Lezyne did keep working but once turned off it wouldn't turn on again until it had dried out.
At only 7 lumens its not something I'd want to use as my solo lighting source as its not bright enough to stand out against street lighting and car tail lights but out on the dark lanes things are a better as the various flashing modes are quite conspicuous. The fact that you can get the Femto online for about £8.50 though means you could deck yourself and your bike out like a Christmas tree for minimal expense.
The Femto is up against plenty of opposition at this price point, most notable are Cat-Eye's Nima and the Izone Pulse, both very similar in their outputs and burn times. You can get the Knog Strobe though for very similar money and that knocks out a whopping 25 lumens with longer burn times than the Femto from the same CR2032 batteries.
On the whole the Femto is best used as an additional/emergency light due to its minimal output especially if you ride in lit up areas. The battery life is pretty average against some of its rivals but they are quick and easy to change so you could easily carry a couple of spares with you.
On the plus side the machined body looks smart and makes a change to the plastic normally found at this price. The range of seven colours also allows you to add a bit of bling to your bike. The dual purpose bracket also makes fitting the Femto to clothing, bags easy and is probably what the Lezyne is best used for.
Smart looking, cheap emergency back-up light with an innovative mount.
road.cc test report
Make and model: Lezyne Femto Drive LED - Rear light
Size tested: Silver - Rear Light
Tell us what the light is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
The Femto is part of Lezyne's Sport line up which is a step down from their big lumen lights its more intended as a back-up emergency style offering. It does okay at this but the low 7 lumen output means it doesn't really stand out in highly lit areas.
Tell us some more about the technical aspects of the light?
CNC'c aluminium body
Uses 2x CR2032 batteries
Clip & band on bracket
Feels a bit flimsy but then it does only cost around a tenner.
Its a neat design with some clever touches. The range of colour options makes coordination with your bike a must.
Clip it to clothes or bags or wrap the band around the seatpost - your choice.
It kept working in the wet although it did conk out once the button was pressed and needed drying out before it started up again.
Non-rechargable Cr2032 batteries offer a decent life, 30hrs constant/60hrs flash but will start to fade long before they actually run out.
Tell us how the light performed overall when used for its designed purpose
As a back up, get you home light it'll do the job. Keep an eye on the batteries though.
Tell us what you particularly liked about the light
The smart design and colour options.
Tell us what you particularly disliked about the light
The weak total light output.
Did you enjoy using the light? Yes.
Would you consider buying the light? No.
Would you recommend the light to a friend? Yes.
About the tester
I usually ride: Whatever needs testing or Genesis Flyer, fixed of course! My best bike is: Kinesis T2 with full Centaur Red
I've been riding for: 10-20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: time trialling, commuting, club rides, sportives, fixed/singlespeed,