Last updated on September 17th, 2026
Quick answer: the KUIU Vital S3 is the current, more substantial successor to the Peloton 97 idea, but it is not a like-for-like ultralight replacement. The Vital S3 Zip-T uses a 127 g/m2 brushed fleece and weighs 7.2 oz / 210 g in large. The old Peloton 97 Zip-T was built around 97 g/m2 fleece and was commonly listed at about 4.9 oz. Choose the S3 for a closer-fitting cold-weather base layer with modern stretch and odour control; keep the Peloton 97 if its unusually low weight is the reason you value it.
KUIU Vital S3 vs Peloton 97 Specifications
| Detail | Vital S3 Zip-T | Peloton 97 Zip-T |
|---|---|---|
| Current status | Current 2026 product | Discontinued; outlet or used stock only |
| Fabric weight | 127 g/m2 | 97 g/m2 |
| Garment weight | 7.2 oz / 210 g in large | About 4.9 oz / 139 g in large |
| Fabric | 90% polyester, 10% XLANCE | Light brushed Peloton fleece |
| Fit | Athletic, next-to-skin base-layer fit | Very light fitted fleece base or mid layer |
| Main role | Cold-to-frigid, high-output base layer | Maximum warmth-to-weight and packability |
| Odour treatment | Toray Makspec antimicrobial treatment | Varied by production generation |
The numbers show the main decision. The S3 fabric is roughly 31% heavier by area and the Zip-T is around 47% heavier as a finished garment than the commonly published Peloton 97 figure. That does not make the S3 worse, but it does mean buyers should stop treating the two names as interchangeable.
What the Vital S3 Changes
KUIU describes the S3 as drawing inspiration from the Peloton 97 while using a new fit and fabric. The inside is soft-brushed to hold warm air against the body. The half zip provides mechanical ventilation, and flat seams, layered thumbholes, a drop-back hem and hybrid raglan sleeves are intended to keep it comfortable under other layers.
The most meaningful material change is XLANCE, a stretch fibre KUIU uses instead of ordinary elastane. The design claim is better resistance to sweat, UV, heat and loss of shape, with lower-force stretch that should feel less restrictive. Those are KUIU’s material and design claims; fabric weight and garment fit remain separate considerations.
- More warmth and coverage: the 127 g/m2 fleece sits above the old 97-weight fabric.
- Base-layer positioning: KUIU explicitly places the S3 next to skin in cold to frigid conditions.
- Modern stretch package: 10% XLANCE is intended to improve recovery and long-term shape.
- Odour control: the fabric includes Toray Makspec antimicrobial treatment.
- Higher carried weight: the Zip-T is no longer in the same five-ounce niche that made the Peloton 97 unusual.
Why the Peloton 97 Built Such a Following
The Peloton 97 became popular well beyond hunting because it packed a hood or zip, a brushed inner face and useful warmth into roughly five ounces. Its appeal is the combination of warmth-to-weight, soft next-to-skin feel, quick drying and small packed size.
That light fabric also has compromises: it can snag and show pulls, and it does little to stop wind on its own. It worked best as an active layer or under a shell rather than as a durable scrub-bashing outer. That context matters when people ask KUIU to reproduce the same weight without the same compromises.
What I value in the Peloton 97 is the warmth it adds for very little weight, along with how readily it dries. Those are practical advantages in a layering system, but they do not make it a stand-alone answer to wind or sustained cold. I judge the Vital S3 against that same balance of warmth, moisture management and the room it needs under an outer layer.
Is the Vital S3 a True Peloton 97 Replacement?
It replaces the role in KUIU’s current range more than it replaces the exact product. Both are light brushed synthetic layers with a close fit, zip ventilation and a focus on moisture management. The S3 adds fabric weight, stretch content and a more explicit cold-weather base-layer brief.
For a hunter who wanted the Peloton 97 because it was almost weightless, the answer may be no. An extra 71 grams is noticeable in an ultralight clothing list. For a hunter who wanted the same general idea with more warmth, a more secure fit and current support, the S3 is the logical KUIU option.
Vital S3 vs Peloton 200
The current Peloton 200 remains a different layer. KUIU lists the Peloton 200 Zip-T at 10.2 oz / 289 g and positions it as a packable mid layer for mild conditions. The Vital S3 is lighter, closer fitting and intended as a base layer in colder conditions. The Peloton 200 makes more sense when you want a conventional fleece over another base layer.
| Use case | Better starting point | Reason |
|---|---|---|
| Cold active climb under a shell | Vital S3 | Close fit, half zip and moisture-wicking base-layer role |
| Mild-weather fleece over a thin shirt | Peloton 200 | More conventional mid-layer fit and weight |
| Lowest possible carried weight | Peloton 97, if already owned | It remains much lighter than either current option |
| Scrub as an exposed outer layer | Neither first choice | Use a more abrasion-resistant outer and protect the fleece |
Fit and Layering
KUIU describes the Vital S3 as an athletic next-to-skin layer designed to work under the same nominal size in mid and outer layers. Do not automatically size up because KUIU has a trim reputation. Measure first, then use the KUIU sizing guide to separate base-layer fit from jacket layering room.
A fitted base layer should contact enough skin to move moisture without restricting shoulder movement or pulling the hem out when reaching. The half zip is useful for heat dumping, but a cold-weather fleece can still be too much directly against skin during hard Australian climbs. Match it to output, not the word “base layer” alone.
Who Should Buy the Vital S3?
- Buy it if you want a current KUIU synthetic base layer for cold, high-output hunting.
- Buy it if a next-to-skin fit, half zip, thumbholes and odour treatment match your layering system.
- Keep your Peloton 97 if it still fits and minimum carried weight is the main reason you own it.
- Protect either fleece with an outer layer when abrasion and exposed scrub are the main concern; stretch content does not make a light fleece a tough outer shell.
- Choose Peloton 200 instead if you want a roomier mid layer rather than a fitted fleece base layer.
My Verdict
The Vital S3 looks like a sensible evolution for hunters who wanted more than the Peloton 97’s extreme minimalism. It brings a warmer 127 g/m2 fabric, a purpose-built next-to-skin fit and a stretch package designed for durability and shape recovery. The cost is the very thing Peloton 97 fans notice first: weight.
I would treat the S3 as a new product with a familiar design idea, not as Peloton 97 version two. The deciding factors are warmth, moisture comfort, fit under other layers and carried weight. My preference is to choose the layer for that role rather than expect the S3 to reproduce the Peloton 97’s unusually low weight.
KUIU Vital S3 FAQ
Did KUIU discontinue the Peloton 97?
The Peloton 97 is no longer part of KUIU’s current main range. Remaining pieces may appear through outlet or used channels.
Is the Vital S3 warmer than the Peloton 97?
The S3 uses a heavier 127 g/m2 brushed fleece versus the Peloton 97’s 97 g/m2 fabric, so more warmth is a reasonable design expectation. Fabric weight alone is not a warmth rating: fit, activity level and the rest of the layering system also matter.
How much heavier is the Vital S3 Zip-T?
KUIU lists 7.2 oz / 210 g in large. The Peloton 97 Zip-T was commonly listed around 4.9 oz / 139 g, making the S3 about 71 g heavier.
Can the Vital S3 be worn as a mid layer?
It can be layered over a very thin base, but KUIU designs it primarily as a fitted base layer. The Peloton 200 is the clearer current mid-layer option.
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