2027 Atomic Redster STR F5 Ski Boots

A slim foot and a slighter build don't have to mean giving up power, and the Atomic Redster STR F5 proves it as one of the stiffest, most uncompromising race boots Atomic makes. Thinner STR shell walls built from temperature-stable polyurethane wrap a very narrow race last, and a thick plug-style race sole must be ground to fit the racer and binding before the boot can be used. It's a World Cup-level competition boot that delivers instant, unfiltered power to the ski for elite racers working hand in hand with a bootfitter.

Why we like it:

The Redster Racing Sole is thicker underfoot, adding leverage and power transfer that elite racers feel immediately at the top of the turn. We also love the 55 mm Professional Dual Strap, which combines a shock-absorbing elastic section with a static section for a cuff closure that's both tight and lively.

Who it's for:

This boot is for elite FIS and World Cup racers with a lighter, slimmer build who still demand the stiffest flex in the line. It suits a narrow, low-volume foot with a slim heel and low instep, and a racer who has a bootfitter ready to grind, punch and align the shell.

Highlights:

The Redster Racing Sole is the headline, a thicker race sole intentionally delivered outside the ISO 5355 alpine standard so it can be ground to each racer's stance and binding setup before use. Above it, STR Wall Thickness keeps the shell slimmer than the TR boots, while Formula PU holds its 150 flex consistent through cold mornings and warmer afternoons. The 91 mm race last is low volume from heel to toe, and the Race Chassis with 1° sole canting gives a bootfitter a precise starting point. Podium Geometry builds in a 4° ramp angle and a default 16° forward lean that can be pushed to 18°. The World Cup Race Liner adds the Redster AFS tongue, ankle retention lacing and a dual Velcro spoiler, and four Magnesium Elite buckles with the 55 mm Professional Dual Strap close it up.

Things to consider:

This is not a boot that can be bought and skied the same day. The racing sole must be ground by a qualified technician to meet binding standards before use, and the 150 flex and narrow last are built exclusively for elite competition, so it is not appropriate for recreational skiing in any form. Racers who want the same slim STR shell with an alpine-certified sole should look at the STR F4.

Fit & sizing considerations:

The 91 mm race last puts the STR F5 firmly in low-volume, slim-fit territory. A full fitting with a certified bootfitter is essential, both for shell modifications and for grinding the racing sole, before this boot ever goes on snow. A size adjuster insert for a half-size reduction is included.