Union Astra Step On
Step On family · 2026/27
Terrain
Flex
Mid flex — 6 on Union's own 1-10 scale
Flex ratings are the brand’s own and do not compare across brands.
Union's Astra Step On is the women's build of its step-in binding. You step down onto it in Burton Step On boots, it clicks shut at three connection points, and you ride — no ankle or toe straps to ratchet. Union scores it All-Mountain 9/10 on its own card, with Performance, Freestyle and Freeride all at 7/10, and reads the flex as a mid 6 on its scale. Those are Union's numbers, not ours.
The Astra's feel comes from its women's chassis. The S1 Step On W Duraflex ST baseplate and highback run a softer tune than the Duraflex CB on the unisex Atlas Step On, so it rides playful and forgiving rather than race-bred — which lines up with that mid flex and the all-mountain lean. A Hi-Flex HP EVA bushing under the baseplate takes some of the chatter out of hard, chopped snow, and a two-stage integrated forward-lean adjuster lets you tighten or relax the heelside response. There is no canted footbed.
But the Astra asks for one thing before anything else: Burton Step On compatible boots. This is a step-in system, so ordinary strap boots physically cannot lock into it — buying the binding means committing to the Step On boot ecosystem, which is a real cost and a real constraint, not a footnote. You also give up the run-to-run micro-tuning that ankle and toe straps allow. Weigh that honestly before the convenience wins you over.
Within Union's line the Astra sits next to two alternatives worth naming. The unisex Atlas Step On is the firmer, heavier option on the same system — Duraflex CB, 1.70 kg a pair, and a size run that reaches XL — so a rider who wants more response or a larger size looks there. A women's strap binding such as Union's Juliet keeps you free to ride any boots on any board and dial in strap tension, everything a step-in trades away for speed. The Astra is the pick when click-in convenience matters more than that freedom.
Two practical notes. On the board, the Step On disk mounts on 2x4 insert boards and on the Burton Channel. On size, the women's Astra runs S to L — there is no XL — and binding size follows your boot, not your weight; Union has not printed the per-size boot range for 26/27, so tell us your Step On boot and we will confirm the fit. We have not ridden the 26/27 Astra ourselves — this is read from Union's catalog and order sheet.
Will it fit your board?
The mounting disk fits 2x4, EST/Channel insert patterns.
Technology
Step On Instant Connection System
The boot steps down onto the binding and clicks into three connection points — two at the toe, one at the heel — with no ankle or toe straps to ratchet. You are in and riding within a second or two, but it only accepts Burton Step On compatible boots.
S1 Step On W Duraflex ST chassis
The women's baseplate and highback are molded in Duraflex ST, a softer tune than the Duraflex CB on the unisex Atlas Step On. It gives the Astra a mid, playful flex that suits all-mountain riding over a stiff freeride feel.
Integrated 2-Stage FLAD
A built-in forward-lean adjuster on the highback with two stages. More lean tightens the response into heelside turns; less keeps the highback upright and relaxed.
Adjustable Gas Pedal
The toe ramp under the ball of the foot slides to match boot length, lining the boot up over the board edge so edge-to-edge input feels direct rather than vague.
Hi-Flex HP EVA bushing
An EVA bushing under the baseplate that soaks up chatter underfoot, so hard, chopped-up snow reads as less jarring through the feet.
Features
- ·Non-Stick HP EVA footbed
- ·Extruded 3D Aluminum heelcup
- ·Grade 8.8 steel hardware
- ·Step On 4x2 and Channel mounting disks
Strengths
- +Fastest entry and exit — step down, click in, and ride, with nothing to buckle at the top of the lift.
- +Union scores it All-Mountain 9/10 on its own card — a genuinely capable all-mountain feel, not a convenience-only compromise.
- +Light at 1.60 kg a pair, lighter than the unisex Atlas Step On.
- +Mounts on both 2x4 insert boards and the Burton Channel.
- +Mid flex 6 on Union's scale — approachable but not a soft park noodle.
Best For
Women riding all-mountain who already own or will buy Burton Step On compatible boots and want to click in and go — no straps, no buckling at the top of the lift — on a board with 2x4 inserts or a Burton Channel.
Limitations
- −Works only with Burton Step On compatible boots — ordinary strap boots cannot lock into it, so the binding commits you to the Step On boot ecosystem.
- −No run-to-run micro-tuning — a step-in has no ankle or toe straps to fine-tune.
- −Softer W Duraflex ST tune — not a stiff, hard-charging freeride chassis.
- −No canting, and the women's run stops at L (the unisex Atlas Step On reaches XL).
- −No independent 26/27 ride data yet — this is a catalog-and-order-sheet read.
Not For
Riders without Burton Step On boots — ordinary strap boots physically cannot lock into this binding. Also riders who want to keep their current strap boots or mix boot brands, riders who want the run-to-run micro-tuning of ankle and toe straps, and riders needing an XL, since the women's run stops at L.
Sizing
Binding size follows your boot, not your weight or your height.
| Binding | US boot | EU boot |
|---|---|---|
| S | Follows your boot | Per-size range not published |
| M | Follows your boot | Per-size range not published |
| L | Follows your boot | Per-size range not published |
Specs
- Entry system
- Step On step-in — boot clicks in at three points, no straps
- Boot compatibility
- Burton Step On compatible boots only
- Flex
- 6 on Union's 1-10 scale
- Union ratings
- All-Mountain 9/10 · Performance 7/10 · Freestyle 7/10 · Freeride 7/10 (Union's own)
- Weight
- 1.60 kg per pair
- Baseplate
- S1 Step On W Duraflex ST
- Highback
- S1 Step On W Duraflex ST
- Bushing
- Hi-Flex HP EVA
- Footbed
- Non-Stick HP EVA
- Canting
- No
- Forward lean
- Integrated 2-Stage FLAD
- Heelcup
- Extruded 3D Aluminum
- Hardware
- Grade 8.8 Steel
- Mounting disk
- Step On 4x2 Disk, Step On Channel Disk
- Board compatibility
- 2x4 inserts, Burton Channel
- Sizes
- Women's S, M, L (no XL)
- Colors
- Black, White, Lilac
- MSRP
- $399.95
Common Questions
- Can I use the Astra Step On with my current snowboard boots?
- Only if they are Burton Step On compatible. Step On is Burton's step-in standard, and the boot clicks into the binding at three points with no straps. Ordinary strap boots cannot lock in, so plan on Step On boots to ride this binding.
- Will the Astra Step On fit my board?
- The Step On disk mounts on 2x4 insert boards and on the Burton Channel. If you are not sure what your board uses, ask us and we will check.
- What size Astra Step On should I order?
- Size follows your boot, not your weight. The women's Astra runs S, M and L — there is no XL. Union has not printed the per-size boot range for 26/27, so tell us your Step On boot size and we will confirm it.
- Does the Astra Step On have a release like a ski binding?
- No. A snowboard binding has no DIN and no release setting; it holds your boot to the board. Its specs describe feel and response, not protection.
- How is the Astra different from the Atlas Step On?
- Same step-in system, different tune. The women's Astra uses a softer Duraflex ST chassis, comes in lighter at 1.60 kg a pair, and runs S to L. The unisex Atlas uses a firmer Duraflex CB, weighs 1.70 kg a pair, and reaches XL.
