On-One XC helmet review

Can you really get a decent mountain bike helmet for £20 / $30? This On-One XC helmet review aims to find out

On-One XC helmet
(Image: © Guy Kesteven)

BikePerfect Verdict

Decent shape with reasonable ventilation, fit and comfort at a super low price, but side buckles need TLC


  • +

    Good looking shape

  • +

    Upper and lower hardshell

  • +

    Very light

  • +

    Decent venting

  • +

    Washable pads

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    Bug mesh

  • +

    Loads of colors


  • -

    Only two sizes

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    Translucent peaks

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    Side buckles need TLC

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Planet-X currently starts its On-One helmet range with the Enduro at £14.99 but the all-rounder On-One XC helmet is a breezier, lighter and more universal fitting option for just £5 more. The Planet X brand might be predominantly UK-based, but it also will happily ship to the rest of Europe and the United States.

The On-One XC's detailing is impressive considering the price is a mere £19.99 ($30.18, €24.99). The EPS foam body is enclosed by a two-piece in-molded hard shell that also covers the lower edges of the helmet. That’s very rare in a helmet at £50, let alone less than half that, and keeps the liner protected and looking good far longer than ‘naked’ foam. 

There are only two sizes but the shaping is comfortably universal, and the fixed position, dial tightened cradle takes up any excess slack with a pad to reduce pressure. The one-piece removable pad for the front and crown also includes bug mesh to keep stinging things off your scalp. There’s a removable chin strap pad too, which helps tidy up the long strap. The locking side buckles are a bit fragile though, so set them to the correct spot and leave them if you can.

As well as feeling as secure as a much more expensive helmet, the 20 mid-sized vents are backed up with internal channeling. That’s pretty much unheard of at this price and means significant cooling airflow for summer comfort. At under 230g, it’s light as well as airy on your head but there’s still extended behind ear coverage, and it exceeds the relevant EN/BS safety standards.

The only real giveaway of the super low pricing is the translucent orange plastic used on the peak and rear fin of some of the colorways, but it’s much less obvious on the black peaks. While the peak is fixed position, it’s well placed too and we’ve had no issues with it popping off in use or transport, despite using the lid regularly for several months. The pads are washable if they start to stink too.

If you want a more solid-looking 'aggro' lid the On-One Enduro has a bigger peak, deeper coverage and fewer, smaller vents. That makes it a lot hotter though, and the much-rounder head form meant it didn’t fit as many testers as the XC. 


Modern styling, proper channeled venting, upper and lower hardshell, low weight and impressive all-day comfort make the On-One XC an absolute bargain for general MTB or gravel riding. 

Tech Specs: Planet-X On-One XC helmet

  • Price: $30.18 / £19.99
  • Weight: 228g (S/M)
  • Sizes: S/M and L/XL
  • Colors: Gloss black and neon yellow, matte black, orange and black, white, orange and white, and olive.
Guy Kesteven

Guy has been working on Bike Perfect since launch in 2019. He started writing and testing for bike mags in 1996. Since then he’s written several million words about several thousand test bikes and a ridiculous amount of riding gear. To make sure he rarely sleeps and to fund his custom tandem habit, he’s also penned a handful of bike-related books and talks to a GoPro for YouTube, too.

Current rides: Cervelo ZFS-5, Specialized Chisel, custom Nicolai enduro tandem, Landescape/Swallow custom gravel tandem

Height: 180cm

Weight: 69kg