Specialized Propero 4 helmet review

Specialized’s Propero 4 helmet is the brand’s second-tier road helmet that sits underneath its S-Works line of more specialist lids. 

The helmet has received quite the overhaul in its new fourth generation. While the Specialized Propero 3 took cues from the then-flagship S-Works Prevail II, designed to prioritise light weight and hot-weather ventilation, the brand has gone for a different approach with the Propero 4. 

Speed is now on the menu, with Specialized effectively combining the aerodynamic and ventilation properties of the S-Works Evade 3 and Prevail 3 helmets into a single, more affordable package. 

With the Propero 4 intended to perform double-duty, there has been a significant price hike from the £110 RRP of the Propero 3 to £165 / $200 / €190 / AU$310 for the new helmet. 

Fortunately, it has proven to be a very solid performer in testing and, outside of hot temperatures, it could be all the helmet you’ll ever need without the S-Works price tag. 

Specialized Propero 4 helmet specification

Specialized has put a lot of effort into aerodynamically optimising the Propero 4 and you can tell it’s cut from the same cloth as the S-Works Evade 3 when comparing the helmets side-by-side. 

The brand says it drew inspiration from the leading edge of the Evade 3 and used its Win Tunnel (the brand’s own wind tunnel) to test and shape the Propero 4. 

When Specialized arrived at the two highest-performing prototype shapes, it tested them at different yaw angles to gain an insight into how the helmet would perform in more realistic wind conditions out on the road. 

All this results in Specialized claiming the Propero 4 is four watts faster than the S-Works Prevail 3 lightweight lid. According to the brand, this translates to a 15-second advantage over 40km at an unspecified speed. 

Specialized also looked to its S-Works Prevail 3 helmet for ventilation inspiration and while visually, the Propero 4 looks like a closer sibling of the Evade, there’s some interesting technology under the skin designed to cool your noggin. 

The Propero uses Specialized’s new ‘micro channelling’ technology, which sees 2mm-offset channels incorporated into the helmet. The brand claims this creates 'turbulence' in the airflow throughout the helmet, thereby improving ventilation. 

In total, the Propero 4 has seven vents at the front and side of the helmet and five at the rear (the Evade 3 has nine vents in total). The central front channel is significantly bigger than that of the Evade 3, as are the rear vents. 

The Propero 4 incorporates a MIPS C-Solution liner to bolster protection. Although, in essence, this is a downgrade on the MIPS Air Node system found on the S-Works helmets, the Propero 4 has also earned a five-star rating from independent tests carried out by Virginia Tech. 

The Propero 4 features in-built storage for cycling sunglasses and Specialized continues to use its Adjustable Tri-Fix web strap system for claims of added comfort. 

There are five colour options – white, black, Dark Navy Metallic, Powder Indigo and Hyper Dove Grey, with three size options, from small to large. 

On the scales, my size-large Propero 4 CE helmet weighs 319g, 1g lighter than claimed. 

Specialized Propero 4 helmet performance

I’ve been testing the Propero 4 since its launch in February. Conditions have ranged from mid single-digit temperatures to 25°C heat. 

Like the Evade 3, the Propero 4 manages to balance aerodynamics and ventilation with a more ‘everyday’ appearance. The helmet has a premium finish, and although the Hyper Dove Grey colourway isn’t my cup of tea, there’s likely to be a colour to suit you from the five available options. 

The Propero 4 seems well suited to fairly wide oval-shaped heads (like mine) and it sits a little higher on my head than the S-Works Evade 3, but also closer to my ears due to its taller profile. 

This wider fit better suited my head, representing an improvement over the Evade, but as with any helmet, it’s best to try on for size and fit first. 

The padding is also more generous than the Evade, which has pluses and minuses (more on that later). 

The tried-and-tested Adjustable TriFix webbing system was easy to adjust to tailor the fit of the helmet to my head. 

My only real criticism with the fit is that the cranial support could use more up-down adjustment, for greater coverage. In this regard, my gold standard for fit continues to be the Kask Valegro, which provides better overall coverage.

The Propero 4 proved a valiant performer when riding quickly. Although outside of a wind tunnel it’s nigh-on impossible to quantify the aerodynamic performance, it didn’t feel as though it was slowing me down. 

I found it difficult to detect the small 10 per cent claimed improvement in ventilation when switching between the Propero 4 and Evade 3 helmets, even in the cold where airflow is easier to feel.

When riding in 25°C, although sweat didn’t drip onto my sunglasses or face when riding, I found the padding at the front of the helmet became significantly more saturated than I’m used to.

This isn’t something I experience when using the Evade, and I think it’s because the padding is more minimal. 

It’s worth pointing out that I tend to feel the heat more than most, and I would always opt for a lightweight helmet in warmer temperatures, given the choice. 

That might mean the Propero 4 isn’t your one-stop helmet shop for year-round riding if you ride frequently in a warm climate. 

On the flipside, I appreciated the lesser ventilation of an aero-optimised helmet for the majority of the cooler winter and spring transitional rides I carried out the bulk of my testing in.

The helmet performed as well as most of the competition when storing sunglasses. The two front side vents securely held my POC Crave Clarity, Koo Alibi and Oakley EV Zero Blade glasses. It’s worth noting that whenever I looked down, the Oakleys would move slightly, as if held more loosely.

I'd also advise checking your sunglasses are held firmly before buying the helmet, though, because the arms of my Scott sunglasses didn’t fit. 

Although the Propero 4 represents a £55 price hike over its predecessor, I think it's mostly justified with strong overall performance, plus the more premium aesthetic. It certainly makes the Propero 3 look dated. 

Specialized Propero 4 helmet bottom line

The Propero 4 offers excellent all-round performance and comfort, balanced with reassuring safety claims that I hope you will never have to test out.  

Although it seems to have a greater aero leaning than Specialized lets on, its ventilation is sound for an aero road helmet. 

For those who regularly ride in hot conditions, the Propero 4 wouldn’t be my first pick but otherwise, this is a very strong effort from Specialized with little to fault for riding in temperatures under 20°C (or so). 

If the retention dial had the ability to sit further down the back of your head, it would score closer to full marks.