Sea to Summit Ascent Women's Down Sleeping Bag
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Ascent Women's Down Sleeping Bag
Sleep System · Three-Season Backpacking · Women's Specific
In colder temperatures, cinch down the technical hood, zip up the draft-tube protected zippers and allow the 750+ Ultra-Dry Goose Down to keep you warm. As temperatures rise, unzip the Free-Flow Zip system for additional ventilation or completely unzip to be a quilt for use during extra warm nights. The Ascent is one of very few true three-season backcountry bags available. You can even close the snaps at the shoulders, open the footbox zipper and wear the Ascent at camp — giving you real freedom on your backpacking adventures.
Three-Season
One of very few true three-season backcountry bags — usable spring, summer, and fall. Two temp ratings (30°F and 15°F) for different climates.
Women's Specific Fit
Narrower shoulders, widest point at hips — allows natural side-sleeping position. Insulation deployed where women need most warmth.
750+ Ultra-Dry Down
Premium 750+ fillpower goose down with non-PFAS Ultra-Dry Down treatment — maintains loft in damp conditions.
Free-Flow Zip System
Full-length + half-length zipper on opposite side for excellent temperature regulation and multiple sleeping bag configurations.
Quilt Mode
Fully unzipped, the Ascent functions as a quilt — versatile for warm nights. Snaps at shoulders hold the bag in place.
Box Baffle Construction
Box baffles throughout with vertical baffles in torso — minimises down shift, maximises warmth retention.
Women's Specific Fit (NEW — KEY FEATURE)
The Ascent Women's uses a women's-specific fit — engineered for women's body geometry rather than a unisex cut shrunk down. Three key differences:
- Narrower shoulders — reduces internal dead air space (less air to heat)
- Widest point at the hips — accommodates natural side-sleeping position without compressing the down at the hips
- Insulation deployed where women need most warmth — typically more insulation at the chest/footbox and less in the torso vs unisex cuts
Per STS FAQ: "Narrower shoulders, the widest point at the hips to allow a woman to assume a natural, side-sleeping position, and insulation deployed where women need most warmth."
750+ Fillpower RDS Goose Down
Premium 750+ fillpower goose down — RDS-certified, treated with non-PFAS Ultra-Dry Down. 750+ fillpower is mid-to-high tier (vs Alpine Down's 850+). Combined with RDS certification for ethical sourcing.
Free-Flow Zip System (Same as Alpine Down)
Full-length YKK #5 side zip with two sliders + 1/2 length YKK #5 Free-Flow zip. Multiple ventilation modes — full open (blanket), both open (flat quilt), top only (mummy), half-side (foot ventilation). All YKK zippers (industry-leading brand).
Footbox Opening Zip (NEW — UNIQUE FEATURE)
The Ascent has a footbox zipper (separate from the main zip) — opens the footbox for ventilation OR lets you wear the bag at camp. Per STS description: "You can even close the snaps at the shoulders, open the footbox zipper and wear the Ascent at camp giving you real freedom on your backpacking adventures." A unique feature not found on most sleeping bags — great for camp lounging in cold weather.
Lightweight 20D Recycled Nylon Shell
The shell is lightweight 20D recycled nylon with a non-PFAS DWR finish — same fabric family as the Alpine Down but tuned for lighter weight (the Ascent is a 3-season bag, not extreme winter). 20D balances weight and durability.
Box Baffle Construction (NEW — TECHNICAL DETAIL)
The Ascent uses box baffle construction throughout with vertical baffles in the torso. Box baffles are 3D fabric walls that create individual chambers for the down — prevents down from shifting side-to-side (a problem with simpler sewn-through baffles). Vertical baffles in the torso specifically minimise vertical down shift (where body weight compresses down out of the chest area).
Anatomical Footbox
The footbox is anatomically shaped — wider at the toes for natural foot positioning, narrower at the heel. Improves warmth retention by minimizing dead air space.
Versatility Modes (NEW — PDP SELLING POINT)
Multiple Sleeping Bag Configurations
Per STS description: the Ascent can function as:
- Standard mummy bag (all zippers closed, hood cinched) — cold nights
- Ventilated mummy (footbox zip open, body zip partially open) — moderate nights
- Quilt mode (fully unzipped, snaps at shoulders hold in place) — warm nights
- Wear mode (snaps at shoulders closed, footbox zip open) — camp lounging, walking around camp
This versatility is what STS calls a "true three-season backcountry bag." Most sleeping bags have one or two configurations; the Ascent has four.
Temperature Rating (IMPORTANT)
Two Temperature Ratings Available
The Ascent comes in two ISO Lower Limit ratings:
- 30°F (ISO Lower 18°F / ISO Comfort 30°F) — entry-level three-season bag for summer/fall use
- 15°F (ISO Lower 5°F / ISO Comfort 16°F) — extended three-season bag for cold spring/fall/winter shoulder use
Both come in Regular and Long sizes. The current page is showing the 15°F Regular (per the URL variant).
Temperature Rating (by variant)
30°F Model — ISO Lower Limit
18°F / -8°C
30°F Model — ISO Comfort (Women)
30°F / -1°C
15°F Model — ISO Lower Limit
5°F / -15°C
15°F Model — ISO Comfort (Women)
16°F / -9°C
Dimensions & Weight (by size × temp)
| Temp / Size | Total Weight | Fill Weight | Compressed Volume | User Height |
|---|---|---|---|---|
| 30°F / Regular | 31.5 oz / 893 g | 18.34 oz / 520 g | 6.8 L | 66.93 in / 170 cm |
| 30°F / Long | 35.3 oz / 1001 g | 20.46 oz / 580 g | 7.7 L | 72.05 in / 183 cm |
| 15°F / Regular | 44.1 oz / 1250 g | 25.4 oz / 720 g | 9.8 L | 66.93 in / 170 cm |
| 15°F / Long | 49.5 oz / 1404 g | 28.22 oz / 800 g | 10.9 L | 72.05 in / 183 cm |
Materials & Construction
Shell
100% Recycled Nylon (Lightweight 20D, non-PFAS DWR finish)
Lining
100% Recycled Nylon (20D)
Down Fill
90/10 Goose Down (RDS-certified, 750+ fillpower, non-PFC Ultra-Dry Down treatment)
Stuff Sack
100% Nylon (included, excluding trims)
Zippers
Full-length YKK #5 side zip (2 sliders) + 1/2 length YKK #5 Free-Flow zip + YKK #5 footbox zip
Baffle Construction
Box baffles throughout + vertical baffles in torso
Snaps at Shoulders
Yes (for quilt mode + wear mode)
Fit
Women's specific (narrower shoulders, wider hips)
Performance (STS scales)
Climate
Cold (15°F model) / Cool (30°F model) — both rated for three-season use
Weight Class
Lightweight (3-season backpacking class)
Compatibility
Use Cases
Spring/fall/winter shoulder backpacking, three-season backcountry use, alpine ascents (shoulder seasons), camp lounging in cold weather
Sleeping Pad Pairing
Pair with R 3-5 insulated sleeping pad for full temp rating system
Sleeping Bag Liner Pairing
Compatible with STS Silk Blend, Reactor Lightweight, and Reactor Midweight liners for added warmth
QuiltLock Compatible
Yes — pairs with STS quilts and sleeping pads for hybrid sleep system
Profile
Brand
Sea to Summit (Australian outdoor gear, founded 1994)
Category
Sleeping Bag / Down Sleeping Bag / Women's Sleeping Bag
Activity
Three-season backpacking, spring/fall/winter shoulder trips, alpine ascents (shoulder seasons)
Season
Spring, summer, fall (15°F version extends to winter shoulder)
Cleaning (Down Bag Specific)
Hand wash or machine wash (front-loading washer only, no top-loaders with agitators) in cold water with a down-specific technical wash like Nikwax Down Wash or Grangers Down Wash. Regular detergent strips natural oils from down and degrades the Ultra-Dry Down treatment. Wash infrequently — most down bags only need washing once every 5-10 trips. Spot clean between washes with a damp cloth. Do not dry clean — solvents strip the down treatment and damage the shell DWR.
Drying (Down Bag Specific)
Tumble dry low with 3-4 clean tennis balls or dryer balls — the balls break up down clumps as the bag dries, restoring loft. Drying takes 2-4 hours minimum. Ensure the bag is completely dry before storage — any retained moisture causes mildew and down clumping. Can also air dry in sunlight on a dry day, but fluff by hand periodically.
Storage (Down Bag Specific)
Store UNCOMPRESSED in a large cotton storage sack — not the included compression stuff sack. Long-term compression damages down loft permanently. The included stuff sack is for transport only. STS typically includes a large cotton storage sack with their down bags. Store in a cool, dry place away from direct sunlight (UV degrades the shell fabric and the down).
Ultra-Dry Down Treatment Care
The Ultra-Dry Down treatment is durable but wears off with years of use and washing. Refresh with Nikwax Down Proof or similar down-specific water-resistant treatments after washing. Apply to clean, dry bag and tumble dry low with tennis balls to activate.
Shell DWR Refresh
The shell's non-PFAS DWR will wear off with use. Refresh with a PFC-free spray-on DWR (Nikwax TX.Direct Spray-On, Grangers Performance Repel, Gear Aid ReviveX). Apply to clean bag, let cure for 24 hours before use.
YKK Zipper Care
All three zippers (full-length, half-length Free-Flow, footbox) are YKK #5 — industry-leading brand. After exposure to sand, salt, or dirt, rinse with fresh water. If zippers stick, apply beeswax or a graphite pencil tip to the teeth — avoid silicone-based lubricants which attract dirt.
Snaps at Shoulders
The snaps at the shoulders (for quilt mode + wear mode) should be kept clean and free of fabric debris. If a snap stops snapping firmly, inspect for bent or stretched metal and contact STS warranty service if needed.
Box Baffle Maintenance
Box baffles can develop cold spots over years of use as down shifts between chambers. To re-distribute down: lay the bag flat on a clean surface, massage the chambers with your hands to push down back into even distribution. Do this periodically (every few trips) for optimal warmth.
Long-Term Loft Maintenance
Down bags lose some loft over years of use. To refresh loft: tumble dry low with tennis balls for 30 minutes every 6-12 months. The mechanical action separates down clusters and restores some loft.
Repair
Small shell tears: STS repair patches or any silicone/PU repair tape. Large tears, baffle failures, or zipper failures: contact STS warranty service.
Three-Season Backpacking Tip
The Ascent's true three-season capability makes it a versatile single-bag choice for most backpackers. Pair the 30°F version with a Reactor Liner for cooler fall trips; pair the 15°F version with a Reactor Liner for winter shoulder trips. Use the Free-Flow Zip System aggressively — on warm summer nights, fully unzip and use as a quilt rather than opening and closing the bag repeatedly to vent. The snaps at the shoulders hold the bag in place during quilt mode.
Shipping Policy
Components:
All component items (wheels, drivetrains, suspension, brakes, etc.) ship within 2-5 business days of purchase.
Bicycles:
Complete bikes typically ship within 2–3 weeks due to build, tuning, and inspection times. You will receive tracking information as soon as your order is ready to ship.
Riding Gear & Apparel:
Riding gear and apparel orders (helmets, jerseys, gloves, etc.) ship within 2-5 business days.
Returns & Exchanges:
If you received the wrong size or wish to exchange an item, it must be returned in original condition—unused, uninstalled, and with all packaging intact.
For full details, please see our Refund Policy before initiating a return.
