Head-to-head · Best Bike Helmets

Giro Aries Spherical vs Giro Tremor Child Helmet

Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.

The short answer

Giro Aries Spherical comes out ahead by a narrow margin (4.7 vs 4.5). The gap is mostly about serious cyclists seeking maximum performance — read the strengths below before deciding.

Higher ratedRanked #1 in Best Bike Helmets

Giro Aries Spherical

4.7

$349.95as of Jul 8

The Giro Aries Spherical represents the pinnacle of road racing helmet technology, according to Contender Bicycles, with Virginia Tech lab tests showing it tops all other bike helmets in safety ratings. The helmet features Giro's proprietary Spherical MIPS system combined with 24 vents and AURA II Reinforcement Arch for optimal breathability and protection. YouTube tester Guy Kesterman praised it as the lightest, fastest, and safest helmet ever made by the brand, weighing just 265 grams for medium size. While it excels in safety and comfort, its compact design may not suit all head shapes, and its premium features come with a higher price tag. This helmet is ideal for serious cyclists seeking maximum protection and performance.

Strengths

— Top safety rating from Virginia Tech labs, outperforming all other bike helmets in every category
— 24 vents with deep internal channeling for superior breathability and cooling
— Spherical MIPS system with Progressive Layering Nanobead EPS foam for enhanced impact protection

Watch-outs

— More compact design may not suit all head shapes or sizes
— Higher price point due to advanced safety and ventilation technologies

$349.95 · Check Price on Amazon Full review →

Ranked #2 in Best Bike Helmets

Giro Tremor Child Helmet

4.5

$74.95as of Jul 8

The Giro Tremor MIPS child helmet earns high praise for its exceptional comfort and ease of adjustability, with reviewers noting its superior dial system and excellent ventilation. Parents appreciate the lightweight design and high-quality internal materials. While some find the standard buckle can pinch and the fixed side straps too loose, the helmet's MIPS safety technology and stylish mountain bike design make it a top choice for young riders. It's particularly well-suited for children with smaller heads who need a snug, comfortable fit.

Strengths

— Dial-adjust system has a larger rubber dial for ease of use
— Plenty of vents and internal air channels for great ventilation
— Internal pads are high-quality technical material

Watch-outs

— Standard buckle can pinch
— Fixed side straps can be too loose and cause the helmet to slide back on the head

$74.95 · Check Price on Amazon Full review →

How they stack up

Giro Aries Spherical

The Giro Aries Spherical outperforms the Trek Starvos WaveCel helmet in safety ratings and ventilation, with a lighter weight and more advanced Spherical MIPS system. While the Starvos offers impact protection, the Aries Spherical provides superior breathability and a more aerodynamic fit, making it ideal for serious cyclists.

Giro Tremor Child Helmet

The Giro Tremor MIPS child helmet outperforms the Met Downtown Mips in terms of adjustability and safety with its dial system and MIPS technology, though it's more expensive. Compared to the Giro Guider 4, it offers a more child-specific fit and better ventilation, but both share similar concerns about fixed side straps that can slide back.

Specs side-by-side

Spec	Giro Aries Spherical	Giro Tremor Child Helmet
Weight	265 grams (medium)	255 g
Ventilation	24 vents with deep internal channeling	Plenty of vents and internal air channels
Size	S, M, L	Child: 47-54 cm
Safety Technology	Virginia Tech top safety rating	Integrated MIPS® Brain Protection System
Construction	In-mold with DryCore sweat management	In-Mold Construction
Safety Certification	CE EN 1078	CE EN 1078
Adjustment System	Roc Loc 5+ Air fit system	Dial adjust

← See the full ranking of best bike helmets