The Giro Synthe is a top of the range aero road helmet. We have been testing it throughout the year and have ridden it in pretty much all conditions imaginable. Here is our review.

Product Overview

Overall rating:

Score 9

Giro Synthe


  • Light weight
  • Aero
  • Comfortable
  • Excellent adjustment
  • Great venting
  • Looks cool


  • Expensive


Giro Synthe helmet


Price as reviewed:


Adorning the heads of Katusha, BMC and now Team Wiggins, the aerodynamic Synthe has quickly become the go-to helmet for a number of pro teams, and we can understand why. Having worn the Synthe on the climbs of Majorca in 25°C heat, even when gassing it to the top of Sa Calobra, I felt no overheating or discomfort.

The venting on the Synthe provides excellent cooling

The venting on the Synthe provides excellent cooling

>>> Buyer’s guide to road bike helmets

The venting is superb and there is no penalty compared to a conventional helmet, despite the added aerodynamics. In comparison, the Synthe is considerably cooler than all the other aero road helmets, such as the Specialized Evade and Kask Protone.

The Roc Lock retention system allows precise and secure adjustment

The Roc Lock retention system allows precise and secure adjustment

>>> Does an aero helmet make you faster?

The Roc Lock Air retention system is excellent, allowing for easy one handed adjustment and when wearing gloves. The internal shape is very comfortable and seems to suit a wide array of different head shapes.

Video – How much faster is an aerobike?

Many of the new aero road lids divide opinion with their looks, but despite resembling a clutch of bananas, the Synthe is a great-looking helmet that seems to suit anyone who wears it.  It is expensive preventing a perfect score, but it is the best helmet I have had the pleasure of testing.


The padding is removable and features anti bacterial treatment

>>> How much faster is a TT helmet?

As is the case with most aero helmets, Giro makes big claims with regard to aerodynamic credentials of the Synthe, citing that “our extensive testing reveals that the Synthe is nearly as efficient as the fastest time trial helmets”. In the absence of a wind tunnel, we cannot verify the aero claims, but this helmet certainly doesn’t feel like it slows you down. The Giro Synthe scores high marks for looks, comfort, quality, weight, venting and the huge range of colours.

The rear view of the Giro Synthe

The rear view of the Giro Synthe

For more information head over to Zyro.


The best aero road helmet on the market.


Sizes:S, M, L
Colours:See website (too many to list!)