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The Trajecta from 100% is an enduro-style full-face helmet that offers downhill-certified protection in a lightweight and breezy package. Although, it's pricey, the rotational impact protection system is flimsy and it's best for round heads.

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The Trajecta features a multi-point adjustable visor, a metal D-ring closure and is certified to downhill full-face standards, despite the 24 large vents that make this considerably more pleasant to pedal in than a regular full-face. It's even got an own-brand version of MIPS beneath its antimicrobial liner.

100% has opted to develop its own unique rotational impact protection system for the Trajecta. Dubbed Smartshock, it's like the popular MIPS but without the extra cradle. Instead it uses shock absorbers built into the shell, which the liner then attaches to.

Doing it this way keeps the vents completely unobstructed, but there's a downside: you have to be incredibly careful when you remove the liner. The absorbers pop out of their homes with unfortunate ease. And that renders the system useless.

The Trajecta proves a seriously airy helmet thanks to those 24 gaping vents. I’ve been perfectly happy wrenching up climbs on warm days, without the worry of overheating. It can't match an open face lid for cooling, but it’s not far off.

At 860g the Trajecta is heavier than something like Troy Lee Designs' heavily-vented Stage (704g), it’s still pretty light and the weight isn't noticable in use. It's also worth noting that the Stage is £275.

The Trajecta works fine with goggles and really well with glasses, if that’s your thing, thanks to interior channels on either side. It doesn't impede your breathing or feel claustrophobic either, while there's enough adjustment in the visor to store your goggles underneath. 

While I’m certain the Trajecta is potentially comfy, the fit didn’t work very well for me. I top out the small/medium size at 58cm, and the shaping is fairly round – I was left with an awful lot of pressure on my not-very-round forehead.

After around 90 minutes the pressure becomes too much for me to cope with, and taking it off reveals two 100% logos embossed into my cranium from the Smartshock. It's a huge shame because this is otherwise a fantastic helmet – if you're similarly borderline, and especially if your skull shape is more oval (like mine) than round, think seriously about sizing up.

In true 100% fashion, the Trajecta comes in a plethora of colours and just the two sizes.

If you’re looking for a helmet that offers meaningful protection while staying comfy, light and cool enough for all-day rides, the 100% Trajecta confidently ticks all the boxes. Just do what you can to try before you buy, and take care when removing the liner for a wash.

• www.silverfish-uk.com

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