Which is better for trail and dual-sport riding?

The Bell MX-9 MIPS. It has MIPS, an adjustable visor, a vented roost guard and strong ventilation, all aimed at dirt riding. The O'Neal Sierra is off-road styled but documents fewer of those features.

Does the O'Neal Sierra have MIPS?

No MIPS is stated for the Sierra. The Bell MX-9 MIPS includes a MIPS liner, which is designed to reduce rotational forces in certain impacts.

Which has the better fit range?

The Bell. It comes in XS through XXL with three shell and EPS sizes, so each size uses a closer shell. The O'Neal listing shows only X-Large.

Is the Bluetooth on the O'Neal worth stepping up for?

Only if you want comms without adding a unit. Built-in Bluetooth is the Sierra's clearest advantage. If safety features and fit matter more, the Bell is the stronger helmet.

Bell lists about 1533 g for a size M MX-9 MIPS. O'Neal does not state a weight for the Sierra, so there is no figure to compare.

Can I wash the liner?

On the Bell, yes. The liner is removable and washable with anti-microbial IONIC+ padding. O'Neal does not state liner details for the Sierra.

Bell MX-9 MIPS Disrupt vs O'Neal Sierra Helmet

Buy the Bell MX-9 MIPS if you want a proven off-road helmet with MIPS rotational protection, three shell sizes and broad size coverage. The O'Neal Sierra is the pick only if built-in Bluetooth matters more to you than documented impact technology. The Bell has the clearer safety story and a longer track record with riders; the O'Neal's main edge is connectivity, and its spec sheet is thin on shell, liner and weight details.

Choose the Bell MX-9 MIPS if you ride dirt or dual-sport and want MIPS, a washable anti-microbial liner and a proper fit across three shell sizes.
Choose the O'Neal Sierra if you want a full-face off-road helmet with Bluetooth built in and ECE certification.

Prices

Bell MX-9 MIPS Disrupt: $169.95 at powersportsid.com (last seen Nov 9)
O'Neal Sierra Helmet: $149.00 at eBay (last seen Nov 10)
Difference: the O'Neal Sierra Helmet is $20.95 cheaper than the Bell MX-9 MIPS Disrupt at the latest prices (Nov 9 and Nov 10)

	Bell MX-9 MIPS Disrupt	O'Neal Sierra Helmet
Rotational impact protection	MIPS liner included	Not stated
Shell sizes	3 shell and EPS sizes for a closer fit	Not stated
Size range	XS through XXL	X-Large listed
Bluetooth	None	Built in
Certification	DOT and ECE	ECE
Liner	Removable, washable, anti-microbial with IONIC+ padding	Not stated
Ventilation and visor	Velocity Flow vents, adjustable Flying Bridge visor, vented roost guard	Not stated
Stated weight	About 1533 g in size M	Not stated

Spec	Bell MX-9 MIPS Disrupt	O'Neal Sierra Helmet
Safety Standards	ECE (EU), DOT (US)	—
Head Circumference	55-56 cm	—
Impact Resistance	High impact resistance (Mips energy management …	—
Impact Protection Technology	Mips®, Mips energy management system	—
Rotational Impact Protection	Yes	—
Helmet Size	XL, M, S, XS, XXL	—
Adjustment System	3 shell and EPS sizes for a personalized fit	—
Shell Material	Polycarbonate	—
Construction Type	Polycarbonate shell	—
Liner Construction	EPS sizes	—
Removable Liner	Yes	—
Closure Type	D-ring closure	—

Spec	Bell MX-9 MIPS Disrupt	O'Neal Sierra Helmet
Liner Material	Anti-microbial liner	—
Padding Type	IONIC+™ PADDING	—
Shell Type	Full	—
Face Shield	No	—
Helmet Color	White, Black, Fasthouse Prospect Matte Black/Wh…	—
Helmet Style	Off-road	—
Helmet Finish	Matte	—
Helmet Graphics	Yes	—
Helmet Brim	Yes	—
Helmet Weight

Bell MX-9 MIPS Disrupt vs O'Neal Sierra Helmet

Prices

Bell MX-9 MIPS Disrupt vs O'Neal Sierra Helmet

Prices

O'Neal Sierra Helmet

What separates them

Price history

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