Specialized/Fjallraven Prevail Helmet review: summery lid for bikepacking

Specialized/Fjallraven Prevail Helmet review in a sentence: premium, lightweight cycling helmet for warm-weather cycling, especially well-suited for bikepacking.

Unless you're a professional cyclist or a cycling journalist, you rarely get to test a helmet for two days straight without interruption. I'm neither, even though I love cycling and curate T3's best cycling helmet guide. However, I was lucky enough to be invited for a two-day bikepacking trip in Wales to test Swedish outdoor brand Fjallraven and Californian bike expert Specialized's latest bikepacking collection, which includes the S/F Prevail Helmet.

Riding in the mid-June heat in the beautiful, rolling Welsh countryside proved to be the perfect playground to test the S/F Prevail Helmet's ventilation prowess – we were on the saddle for over nine hours on the first day. How did the S/F Prevail Helmet perform, and should you get one yourself? Read the below review to find out more. 

[First reviewed Jul 2023]

Specialized/Fjallraven Prevail Helmet review: price and availability

The S/F Prevail Helmet was announced in May 2023 as part of the second bikepacking collection from Specialized/Fjallraven. It's available to buy now directly from Fjallraven UK and Fjallraven US for a recommended retail price of £260/ $300—AU price and availability TBC. The S/F Prevail Helmet is built on Specialized's Prevail platform; however, it costs slightly less than that (Specialized S-Works Prevail 3 is sold for £275).

Specialized/Fjallraven Prevail Helmet review: specification

• Best for: summer rides when air flow is crucial
• Size range: small to large
• Material: 100% expanded polystyrene
• Weight: 268 g
• Gender: Unisex
• Activity: Biking
• Environmental info: Produced without PFCs

Specialized/Fjallraven Prevail Helmet review: design and build quality 

The Specialized/Fjallraven Prevail Helmet is all about providing lightweight protection and superb ventilation. It uses the MiPS Air Node security system. This featherlight and slim design does away with the air-blocking foam "bridges" in the centre, creating air channels and allowing plenty of air to circulate under the lid. 

The Air Node system might not be hefty, but it provides an ample amount of head protection, thanks to the AirCage technology that works as a suspension bridge and is "designed to distribute localised forces" throughout the helmet should an impact occur. Full disclosure, I didn't fall off the bike to test this feature.

To ensure optimal fit regardless of head shape, the S/F Prevail Helmet uses what's called the Occipital Base Adjustment. Using the rotating dial at the rear, you can adjust the plastic frame, pulling the helmet as close to your head as required. An adjustable Tri-Fix web system provides even more comfort, and with the ANGi-ready, ultralight Mindset fit system, you can adjust the helmet's height as well.

Specialized/Fjallraven Prevail Helmet review: performance

Being on the saddle all day, ascending and bombing down hills in Wales, is an experience everyone should try at least once. It's also an experience you don't want to be tainted by an ill-fitting helmet, especially if you're out all day. I haven't worn a Specialized helmet for a while before the trip; I usually go full dork and put on my Bern Macon 2.0 for commuting or don my Kask Utopia for faster riders, so I wasn't sure what to expect from the S/F Prevail.

My worries melted away as soon as I pried the helmet out of the box. Using the little dial at the base of my skull, I could tailor the fit of the S/F Prevail Helmet almost perfectly to the shape of my head. It felt like Specialized used my head as a model to create the shape of the helmet; it really was a perfect fit, and I felt no discomfort even after long hours in the saddle.

Another feature that made it possible for me to feel more comfortable was the airy construction of the helmet. There is very little material blocking the air from entering the helmet, keeping your head cool as you ride. The MiPS Air Node system isn't the way, either, whilst also providing a sense of security and protection.

On that note (node?), although I'm pretty sure it's been tested appropriately, I'm not 100% sure about the safety properties of the MiPS Air Node system. It's essentially a soft plastic frame plonked on the foam, which you can peel off and remove. (Not saying you should, though.) It's said to distribute impact force, but I wonder how much it actually helps.

For the price the S/F Prevail Helmet sells, I expect it to be the best of the best. And while the MiPS Air Node might be just that – it's super lightweight, after all – it doesn't fill me with confidence that it can provide all-out head protection, should it be required. It might just be my safety-above-all approach, but I almost wish the helmet was slightly heavier and used 'standard' MiPS.

That said, I felt pretty safe wearing the S/F Prevail Helmet because of the overall lightness and the spot-on ergonomics. One can say I have mixed feelings about the lid, but it's more like an underlying uncertainty than a full-on complaint. I had to find something I didn't like about the S/F Prevail; otherwise, people might think this is an ad, not a review.

Specialized/Fjallraven Prevail Helmet review: verdict

If you need a lightweight, superbly-ventilated jack of all trades cycling helmet, the S/F Prevail Helmet is your best option. It's jam-packed with top-tier technology, which helps keep the weight to the minimum without cutting corners in the safety department.

I tested it in perfect weather conditions (blazing sun, hours on the saddle), and I'm delighted with how it performed. Airflow was always optimal under the lid, and the fit was spot on too. My only grief isn't a real issue, either; I wish the MiPS Air Node system felt a bit more secure – that's all. Other than that, the S/F Prevail is a premium helmet I can wholeheartedly recommend for bikepacking and summer rides in general.

Specialized/Fjallraven Prevail Helmet review: also consider

Delicious styling and a general overhaul to the design and componentry have given the Kask Protone Icon a whole new lease of life. The helmet is supremely comfortable to wear, light enough not to be a hindrance, and, if you get up some decent speed, the improved aerodynamic qualities are easy to witness. Read Rob's full Kask Protone Icon review.

The Lazer Vento KinetiCore Helmet is a fast helmet with performance much like other models in the range. It's on par price-wise with other premium helmets, too, though the limited edition edge of the Wout van Aert Red Bull branding will probably make it more sought after. Read T3's full Lazer Vento KinetiCore Helmet, also by Rob.