The Topeak FlashFender DF is a fast and easy tool-free rear fender that was specifically designed to work with the Duo Fixer mounting system. Designed to slide onto the top of the Duo Fixer mount or the bottom slot with an optional bracket, available with the FlashFender DF Deluxe, the Topeak FlashFender offers convenient and quick protection from rear tire spray. The fender has a simple origami style plastic construction with an attractive $12.95 retail price. Topeak includes a Duo Fixer bracket with the fender which attaches directly to the saddle rails. There are two color options with the FlashFender, a semi-transparent option and the matte black shown here. It’s a lightweight design that’s ideal for riders that want protection from spray without the hassle of full fender sets.

The Topeak FlashFender DF is a simple and budget friendly origami style fender that utilizes the top slot of the Duo Fixer mounting system.

Retail Price$12.95
Measured Weight (in g)28 (fender), 32 (bracket)
Likes+ Quick-release mount
+ Simple and lightweight design
+ Protects you from rear tire spray
Dislikes– N/A
Where to Buy (US)Todson


The Topeak FlashFender DF comes attached to a cardboard backing with specs and branding printed on it. Once you remove the zip tie holding the fender in place you’ll find:

  • FlashFender DF 
  • Duo Fixer mounting bracket

Interestingly, Topeak includes the Duo Fixer bracket with nearly every accessory which means you’ll probably have quite a few brackets if you purchase multiple accessories. There is no fender only option currently available which could theoretically have a lower price.


One of the unique features of the Topeak FlashFender DF is the fact that it’s designed to work with Topeak’s Duo Fixer mounting system. It’s a clever dual-slot bracket that attaches to the rear of the saddle rails. The FlashFender DF slides into the top slot of the bracket and is secured in place with a spring loaded tab. Pushing down the release button on the bracket unlocks the taillight and allows it to be pulled out of the slot. The dual slot design of the Duo Fixer allows you to combine the FlashFender DF with a variety of accessories such as saddlebags or toolkits. Note, Topeak also sells a FlashFender DF Deluxe set which includes a QuickClick adapter to allow you to mount the fender to the bottom slot. This is a useful option if you prefer to use the top slot for taillights like the Topeak TailLux 40 DF.

Topeak FlashFender DF Bike Rear Fender Duo Fixer Review - Duo Fixer Bracket
The FlashFender DF uses the upper quick-release slot of the Duo Fixer bracket.


The Topeak FlashFender DF has a simple plastic origami design that sits right under the saddle to protect you from spray. It’s a similar design to the popular Ass Saver fenders and offers a minimalist design with excellent protection from spray. If you plan to do group rides, you’ll want to invest in a full fender set like the SKS Raceblades that also protect riders behind you from spray. Otherwise, the FlashFender DF is an ideal option for fair-weather cyclists or those in warmer climates who don’t need full fender protection. Unlike the Topeak D-Flash, the FlashFender DF has a simple matte black finish with no graphics. There are three fold lines on the fender, one along the center and two near the mounting bracket. Folding the fender along these lines gives it more of a “V” profile and adds rigidity.

Topeak FlashFender DF Bike Rear Fender Duo Fixer Review - Top View
The FlashFender DF is a simple plastic fender with a fold line along the center to give it a slight V profile.


We utilized the Topeak FlashFender DF on our Decathlon Triban RC 520 along with the Topeak SideWedge saddle bag. The Duo Fixer mounting system was particularly helpful for people like us with multiple bikes, as it allowed us to quickly swap accessories between bikes. This review was well timed as our normal sunny California weather turned into an extended rain storm. The simple FlashFender was a quick and easy way to keep riding without getting drenched from the rear tire spray. We found the simple design to be quite effective at keeping our backsides dry despite the wet roads. Compared to multi-piece clip-on fenders, the simple quick release attachment is far quicker to install and remove from the bike.

Topeak FlashFender DF Bike Rear Fender Duo Fixer Review - Side Profile
Despite the small size, the FlashFender DF keeps your backside dry from wheel spray.


Overall, we found the Topeak TailLux 40 DF to be a simple and well designed Duo Fixer compatible taillight. At 40 lumens the taillight itself lacks the power to be daytime bright and instead has a simple one-level menu and focused lens that’s well suited for nighttime riding or commuting. Aside from the clever built in USB connector, we’d score the taillight on its own an average score as the features and design don’t stand out in such a crowded marketplace. The main selling point for the TailLux 40 DF is the Duo Fixer compatibility which allows it to tuck underneath the saddle using the upper slot of the Duo Fixer bracket. It’s a clever mounting system that eliminates the need for fragile rubber straps or tools. The main negatives we found with the taillight is the fact that you can’t do a long press to turn off the taillight (e.g. you have to cycle through all modes to shut it off) and the lack of a multilevel battery status indicator. That said, if you’re looking for a solid taillight that’s compatible with the versatile Duo Fixer mounting system then the Topeak TailLux 40 DF is a good option.

Disclaimer: The product for this review was provided by Topeak. The views expressed on this website are solely those of the authors and are here to help people make an informed choice before a purchase. The authors or the blog itself does not get any monetary compensation from the product manufacturer or third-party websites/vendor links that are posted here.

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