100% Altis helmet review

100% brings its proprietary Smartshock impact protection system to its mid-range Altis trail helmet

100% Altis helmet review
(Image: © Sean Fishpool)

Bike Perfect Verdict

With the Altis, 100% has produced a solid mid-range mountain bike helmet for all-round riding


  • +

    Good looks

  • +

    Decent ventilation

  • +

    Decent padding

  • +

    Good visor


  • -

    Smartshock buttons may irritate some heads

  • -

    No height adjustment for the fit cradle

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The Altis (and its visorless gravel alter-ego, the Altis Gravel) is a showcase for 100%’s proprietary Smartshock impact protection system, which is also used in its full-face helmets. It’s great to see alternatives to MIPS, especially amongst the best mountain bike helmets under $100 budget, but the system does suit some riders more than others in terms of comfort. If it works for you (as it did for this tester), you’ll find this a decent mid-range choice.

100% Altis helmet pictures showing how the shape of the visor transitions into the vents

Flowing lines give the Altis a premium look (Image credit: Sean Fishpool)

Design and aesthetics 

The $100 / £89.99 Altis is the more affordable helmet alternative to 100%’s mega-ventilated $165 / £140 100% Altec. The Altis has more standard airflow, but it shares some of the good looks and features.

The outer shell sweeps around the sides and back of the EPS foam layer in distinct lines, giving a sleek, fast look. The visor follows the lines neatly, when it’s up or down, and the design means there’s a bit more of the EPS foam exposed around the sides than in many helmets. Our review sample didn’t suffer damage in our test period (thankfully), and the more vulnerable lower edges of the foam are covered by the outer shell, which is a classy touch at this price point.

The light gray colorway of our test model was cool and understated; there’s also a black version, and a white option with red highlights.

A picture showing the inside of the 100% Altis helmet and the Smartshock points positioned inside the helmet

Smartshock uses a series of elastomer plugs which can be seen inside the helmet (Image credit: Sean Fishpool)


Most helmets in this price range have added protection against rotational impacts - usually a system called MIPS (check out our comprehensive guide to MIPS for more on this), but 100% uses its own ‘Smartshock’ system, which is more substantial (but has less independent testing, so far. Smartshock is a series of flexible 2cm-long elastomer plugs which attach to the padding at one end and to small recesses in the helmet at the other. They’re designed to compress and allow some twisting in an impact, so that less force is transferred from the ground to your head. 

Everything is held in place by a pair of hassle-free fixed-length straps around the ears, and a straightforward chunky adjustable chin buckle. At the back, the tightness dial allows fine increments of customization, though the fit system doesn’t have any vertical adjustment. 

The padding is soft and substantial, and the blue Smartshock plugs are prominent in them. The padding is removable for washing - with a bit of care not to damage the plugs - and the helmet comes with a spare thicker set of pads.

100% has recently released an ‘Altis Gravel’ variant of the Altis, which is the same but without a visor, whereas you can clip the visor on and off the MTB version if you wanted the flexibility of both options.

A picture from the back of the 100% Altis helmet showing the vents on the side and rear

The ventilation is airy enough for summer climbing efforts (Image credit: Sean Fishpool)


For me, the Altis was a fine mid-range all-rounder. It was an easy helmet to reach for, with a nice enough fit, decent padding, especially on the brow, and good head coverage. The fit wasn’t quite 100 per cent for me - it had to be snugged up quite tight if I wanted to prevent every last millimeter of movement - but that wasn’t a problem once adjusted.

The visor adjustment was easy and the ventilation was decent; certainly good enough to cope with a spur of the moment hill-reps session in summer, when I would normally have chosen a light road helmet, and nothing that would stop you enjoying the Altis as a year-round lid. 

I couldn’t feel the blue Smartshock plugs against my head while riding, but it’s worth noting that some testers have felt them pressing through the padding, so you might want to test this before you buy. 

At 371g for a small/medium, the Altis is in the average weight range when compared to the best half-shell mountain bike helmets - typically 340-380g - and it felt that way.

100% Altis helmet with the visor in the highest position

The visor has a good range of adjustment (Image credit: Sean Fishpool)


The Altis is a good-looking, easy to wear helmet, with nice touches like covered edges on the foam. It’s not particularly outstanding in any way, and you should check that the prominent Smartshock buttons don’t irritate your head, otherwise it’s a well-priced agreeable all-rounder for your shortlist.

Tech Specs: 100% Altis helmet 

  • Price: $100 / £89.99
  • Colors: Gray, black, white 
  • Sizes: XS-S (50-55cm), S-M (55-59cm), L-XL (59-63cm) 
  • Weight: 371g (small/medium)
  • Key features: Smartshock rotational impact protection, spare pads, single-density EPS foam
Sean Fishpool
Freelance writer

Sean has old school cycle touring in his blood, with a coast to coast USA ride and a number of month-long European tours in his very relaxed palmares. Also an enthusiastic midpack club cyclocross and XC racer, he loves his role as a junior cycle coach on the Kent/Sussex borders, and likes to squeeze in a one-day unsupported 100-miler on the South Downs Way at least once a year. Triathlon and adventure racing fit into his meandering cycling past, as does clattering around the Peak District on a rigid Stumpjumper back in the day.

Height: 173cm

Weight: 65kg

Rides: Specialized Chisel Comp; Canyon Inflite CF SLX; Canyon Aeroad; Roberts custom road bike