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The Topeak Taillux 25 DF is a well-designed rear light that tucks in neatly under your saddle for a clean look. Its simple four-mode operation makes it quick and easy to use and it lived up to its waterproof credentials. One of its main selling points is that it's part of Topeak's Duo Fixer range, which lets you easily attach cycling accessories such as a saddlebag, mudguard or mini pump underneath the light. However, it may not be quite powerful enough as a daytime-running light on brighter days.
This rear light from Topeak packs 25 lumens at maximum output on its pulse setting that has a claimed 30-hour runtime, which might not rival the Cateye Viz 150 Rear Bike Light in terms of output, though I did find the output sufficient for all but the very brightest of days. And if you are after a new rear light, do check out our best rear bike lights buyer's guide.
I think the eight red LEDs are responsible for providing enough illumination for night-time riding to keep you seen on unlit roads, where your all-round visibility is helped by the Taillux's 240° spread of light.
The four modes are exactly what you need, and no more. And personally, I only used two of the modes: blink and pulse. These have the longest runtimes, with 30 hours in the pulse setting and nearly two days – an impressive 40 hours – in the blink mode.
In constant mode you're only getting three and half hours, and you'll get 20 hours in its 'sequence' mode.
As the light sits just underneath the saddle, Topeak has placed the function button on the side of the light's body. And though the button is small, I found it easy enough to operate even when I was wearing thick winter gloves.
Charging is a lead-free affair. To charge it you rotate the light to release it from the mount that stays connected to the saddle rails, which reveals the male USB-A portion. You just plug this into your laptop or a wall-mounted charger and three hours later the light's charged. Simple.
As the light sits underneath your saddle, there are no straps to mount the light to your seatpost. There's just a single bolt to clamp the mount to the saddle rails, and there's no play or looseness in the system once it's in place. This system also means that your seatpost won't get scratched by any light fitting, which may be a consideration for some of us.
The IPX6 water-resistance rating is very welcomed in a rear light, which can expect to receive a lot of high-speed, road-borne spray, especially if you're riding without mudguards. The IPX6 rating means the light can resist high-pressure blasts of water and though I found water would sit around the USB port, the light has still not been disrupted by it.
The £32.99 Topeak Taillux 30 only has five extra lumens over the Taillux 25 DF, and Shaun didn't find it any better than the Taillux 25 DF in bright riding conditions. But it may be an option if you already have a compatible Topeak saddlebag.
Super-bright rear lights are always going to cost you a bit more. But Steve had lots of good things to say about the Lezyne Zecto Drive Max 250. Yes, at £52 it's pricey for a rear light, but he found its 250-lumen output ensured you'd be seen even riding in daylight.
Although not the brightest rear light, the Taillux 25 DF will keep you seen most days and the 240° of illumination it offers will help keep you visible approaching junctions and roundabouts. Topeak's Duo Fixer system is a real selling point, allowing you to attach other cycling accessories underneath your saddle, keeping your seatpost and frame clear of clutter.
Reasonably priced with a wide lighting spread and a handy accessories mount, but not powerful enough for very bright days
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road.cc test report
Make and model: Topeak Taillux 25 DF
Size tested: 25 lumens
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?
Topeak says: "Compact, 8 super bright red LEDs rear light hides beneath the saddle with included Duo Fixer which allows fast and easy tool-free mounting and removal. It provides dual use with Topeak Duo Fixer system accessories, including Topeak QuickClick saddle bags, Tubi tools, CO2 inflators, and fenders. Features convenient cable-free charging with a direct USB port plug."
If you want to mount a light and other Topeak accessories beneath your saddle using Topeak's Duo Fixer attachment system, this is for you. I liked the fact it kept my seatpost looking neat without a light attached.
Tell us some more about the technical aspects of the light?
MAX LUMINOUS INTENSITY - 25 Lumens
LAMP - 8 super bright red LED's
BATTERY - 3.7V 200mAh Lithium Ion (integrated)
CONTROL / BURN TIME (APPROX) - 4 modes:
Constant - 10 lm (3.5hr)
Blink - 10 lm (40hr)
Pulse - 25 lm (30hr)
Sequence - 12 lm (20hr)
CHARGE / CHARGE TIME (APPROX) - USB-A / 2-3 hr
INPUT - 5V 500mA
LAMP HOUSING - Engineering grade polymer
ATTACHMENT - Duo Fixer on saddle rail
COMPATIBILITY - Topeak QuickClick saddle bags, HybridMaster Mini, FreePack, and FlashFender DF with lower bracket
SIZE - 7 x 5.4 x 2.9cm / 2.75 x 2.1 x 1.14in
WEIGHT - 30g / 1.06oz
WATERPROOF - IPX 6
The polymer the light is constructed from feels very sturdy and should survive impact in the case of dropping.
A side button to filter through ON/OFF and its various modes keeps it very simple. And with only four modes to filter through it's quick as well as easy.
The light is mounted securely to the saddle rails using a hex/Allen bolt. I found it a bit of a pain taking the light off its mount, as the light would often catch on the saddle rails.
No problems. I did find that water sat around the USB port but it didn't affect the light's performance.
It took around three hours to fully charge, and with the light set to blink I managed two weeks of riding – around 40 hours – without needing to recharge it.
Not quite powerful enough as a daytime-running light for bright sunny days.
Polymer construction keeps weight down although the mounting surface does mean a bit extra weight.
If you're planning to pair it with other Topeak accessories using Topeak's Duo Fixer system the price makes sense. But as a standalone rear light, it's not quite powerful enough for its £34.99 price.
Tell us how the light performed overall when used for its designed purpose
On a dark day or during the evening, I had no problems being seen with visibility helped by the light's 240° illumination. I found it easy to fit attachments to it and used it as the rear light on my gravel bike with a saddle bag mounted underneath it; a neat setup.
Tell us what you particularly liked about the light
The design keeps the light hidden and neatly tucked in below the saddle.
Tell us what you particularly disliked about the light
The low power output meant it wasn't great for being seen on bright sunny days.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
It's in the region for most rear lights.
Did you enjoy using the light? Yes
Would you consider buying the light? Yes
Would you recommend the light to a friend? Yes
Use this box to explain your overall score
Really nice light to use, especially when paired with the Duo Fixer system that allows you to carry other cycling accessories. I felt it was only let down by the water gathering near the USB port, which could potentially cause trouble. And you do also need to ensure your saddle has enough clearance to fit it.
About the tester
I usually ride: Dolan Rebus My best bike is:
I've been riding for: Under 5 years I ride: Every day I would class myself as: Semi pro
I regularly do the following types of riding: road racing, time trialling, commuting, club rides, Always love some off-road with some mates.