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Zefal Z Aero Frame Bag



Good weatherproofing and well designed, if pricey for its size
Ideal length for bars and gels
Good fitting options
Good water resistance
No head tube/steerer strap to stop twisting

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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The Zefal Z Aero frame bag offers easy access to nutrition and somewhere to store small objects rather than load up a jersey pocket. It's easy to fit in various ways, and good weatherproofing keeps the rain out.

For more ideas and options, check out our feature 15 easy ways to carry stuff on your bike, and for adventures off the beaten track, our guide to the best bikepacking bags.

Compared with many top tube bags we see, the Zefal is on the small side, but as Zefal explains, it is designed primarily for food storage for triathletes and time triallists. It's the ideal length for all of the energy bars or gel packets that I have used, and when packed well you can get plenty of stuff inside.

2023 Zefal Z Aero Frame Bag - open 2.jpg

Its shape and height mean you won't get anything like a phone inside it, but it'll easily accept keys, cash or debit card. Things you might need quick access to.

The polyester 420D TPU material and the sealed zip mean that whatever you put inside remains dry when you are riding in the rain. The zip runs freely, so it's easy to open and close the bag one-handed while riding.

2023 Zefal Z Aero Frame Bag - open.jpg

If you are using a bike that has bolts on the top tube, you can attach the Zefal this way as it has holes on the bottom. There are three in total and they've been elongated to give a bit of adjustment, plus there is a piece of material held in place with Velcro that stops the weather getting in through the holes.

You also have two options of where you want to position the front strap. Zefal has diagrams on its website showing all of the dimensions.

The only thing missing is a strap to wrap around the steerer tube to stop it twisting around the top tube, although being so small in height it's not that big an issue compared with some bags.

The reflective detailing either side is a neat touch, giving a little bit of sideways visibility if you're out into the dark.


At £28.99, the Zefal Z Aero is £11 less than Restrap's Top Tube Bag, although that one is twice the size at 0.8 litre compared with the Zefal's 0.4 litre, and Mike thought it was excellent.

Craft's Cadence Top Tube bag is also bigger at 1.2 litres, and has gone up to £44.99 since our review.

If you want to spend as little as possible, though, Decathlon sells the Van Rysel TRI Bike Frame Nutrition Pouch for £9.99. It is Velcro strap fitment only and doesn't offer the weather resistance of the Zefal, but it is a bargain.


The Zefal is well made and does a great job of keeping out the elements, plus having the different options of fitment is a bonus. The Van Rysel pouch does suggest the Zefal is a bit pricey for the size, though.


Good weatherproofing and well designed, if pricey for its size

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Make and model: Zefal Z Aero Frame Bag

Size tested: 0.4L

Tell us what the product 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?

Zefal says, "The Z Aero is a frame bag designed for tri-athletes and cycling sports people who want to carry their food. The Z Aero is installed on the front of the top tube, either using non-abrasive, self-gripping straps, or using screws. The leak-tight seal guarantees protection when it rains. The interior compartments optimise storage and quick access."

It's a neat solution for carrying small items on any bike.

Tell us some more about the technical aspects of the product?

Zefal lists:

Material: Polyester 420D TPU

Mounting: Universal with self gripping straps or with screws

Dimensions: 220 x 65 x 45 mm

Capacity: 0.4 L

Zip: Water repellent zip

Rate the product for quality of construction:
Rate the product for performance:
Rate the product for durability:
Rate the product for weight (if applicable)
Rate the product for value:

Tell us how the product performed overall when used for its designed purpose

It's a good weatherproof solution for carrying small items.

Tell us what you particularly liked about the product

Zip glides easily for one-handed operation.

Tell us what you particularly disliked about the product

No head tube strap to stop it twisting around the top tube.

How does the price compare to that of similar products in the market, including ones recently tested on

The Craft and Restrap options mentioned in the review are more than double the size for just a bit more cash, and the Van Rysel undercuts it by a lot, albeit for a non-waterproof option.

Did you enjoy using the product? Yes

Would you consider buying the product? Yes

Would you recommend the product to a friend? Yes

Use this box to explain your overall score

It's good, but if you aren't worried about keeping your ride nutrition dry then it is kind of pricey. It does have more attention to detail than cheaper offerings, though, like the option to use bolts and/or straps and the ability to keep the wet out.

Overall rating: 7/10

About the tester

Age: 44  Height: 180cm  Weight: 76kg

I usually ride: This month's test bike  My best bike is: B'Twin Ultra CF draped in the latest bling test components

I've been riding for: Over 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,

As part of the tech team here at F-At Digital, senior product reviewer Stu spends the majority of his time writing in-depth reviews for, and ebiketips using the knowledge gained from testing over 1,500 pieces of kit (plus 100's of bikes) since starting out as a freelancer back in 2009. After first throwing his leg over a race bike back in 2000, Stu's ridden more than 170,000 miles on road, time-trial, track, and gravel bikes, and while he's put his racing days behind him, he still likes to smash the pedals rather than take things easy. With a background in design and engineering, he has an obsession with how things are developed and manufactured, has a borderline fetish for handbuilt metal frames and finds a rim braked road bike very aesthetically pleasing!

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