---
title: "Sierra Designs Flex Capacitor 40-60 L"
name: "Sierra Designs Flex Capacitor 40-60 L"
brand: "Sierra Designs"
description: "Improved version of the popular and very versatile Flex Capacitor backpack."
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  - name: "Sierra Designs Flex Capacitor 40-60 L"
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last_updated: "2026-10-13"
---

# Sierra Designs Flex Capacitor 40-60 L

Brand: Sierra Designs · Category: [Backpacks](/c/backpacks.md)
Backpack size: S/M, M/L · Removable hipbelt: No · Seam-sealed: No

## Offer

- Price: €210.90
- Availability: Out of stock
- Condition: New
- Buy on the website: [HTML product page](/p/sierra-designs-flex-capacitor-40-60-l)

## Description

Improved version of the popular and very versatile Flex Capacitor backpack. With the straps, you can adjust the volume of the backpack between 40 and 60 liters. For its weight, it has really great load capacity and durability, plus it boasts lots of features and a ton of pockets.

The improved version of the popular adjustable backpack with great load capacity and durability.

## Usage

You'll really appreciate the versatility, higher load capacity, and durability of this backpack, especially if you're just stepping into the world of Ultralight Backpacking. At first, you might need the full 60 liters, but as you start reducing the amount of stuff you carry over time, you can cut it down to 40 liters. You'll find that useful even on longer hikes. In one section, you'll get by with food for 3 days, while in another, you'll need supplies for a week. The Flex Capacitor is also **perfect for those whose adventures are pretty varied** – from short weekend trips to long trails or winter crossings.

The backpack has an awesome load capacity compared to other backpacks of similar weight/volume. Even though the manufacturer doesn’t specify the upper load limit, **we’ve loaded this backpack from the previous collection several times over 20 kg**, and it didn’t suffer at all. You can check out our short video presentation of the earlier model. [here](https://www.youtube.com/watch?v=-zLFjuDQIds).

[Video](https://youtu.be/mYBBNGfSae4)

## Pockets wherever you look

The backpack has a total of **9 external pockets**.

- Two smaller pockets on the shoulder straps with elastic drawstrings – perfect for your phone, a small water bottle, or a quick snack.
- Two larger zippered pockets on the hip belt – perfect for your power bank, a quick snack, and the stuff you want to have handy throughout the day but still securely stored.
- Two spacious pockets on the sides of the backpack made of stretchy mesh material – perfect for a big water bottle, a seat pad, or even a down jacket with a rain cover.
- Two more spacious mesh pockets on the sides of the backpack – they'll be perfect for your tent or tarp, food supplies, or other bulkier essentials you want to have easily accessible.
- One big pocket in the lid secured with a zipper and a small carabiner for extra security – for valuable little things like a headlamp or keys, toothbrush, documents.

## **More features**

### **Multipurpose pocket for hydration bladder**

Inside the backpack, there's a removable lightweight pocket for a hydration bladder that you can easily take out using plastic snaps and transform it into a minimalist daypack for a quick jaunt off the trail, a run to the summit, or even a little pack for your kid to feel independent.

### **Main U-shaped zipper**

Thanks to the ergonomic shape of the main compartment zipper, access to your stuff is not just easy, but also super roomy. The durability of the zipper might reliably put off some ultralight extremists, but it guarantees a long lifespan even with less gentle handling. The zipper is also covered with a storm flap for better weather resistance.

## Materials and construction

The body of the backpack is made from a sufficiently durable material with a distinctive honeycomb pattern, **100D Nylon Honeycomb**. The bottom part of the backpack, which is in contact with the ground, is actually made from a fabric that’s about 4x more durable, **420D Nylon Oxford**. The shoulder straps and hip belt are padded with dense foam that feels a bit firm at first, but loosens up and softens with use. The back section features separate padding under the shoulder blades and lower back. In other areas, your back doesn't touch the backpack at all, which allows for air circulation and significantly reduces sweating on your back.

The volume of the backpack expands sideways, so the center of gravity of the load doesn’t rise high but stays close to your body’s center of gravity. The backpack is reinforced with a **Y-shaped aluminum frame** that's connected to the hip belt. Overall, the load in the backpack feels super comfy and sits great on your back.

The weight of the backpack in size S/M is 1210 g + 50 g for the hydration bladder, and in sizes S/M and M/L it's 1380 g + 50 g for the hydration bladder.

## Specs

- Color: Black
- Backpack size: S/M, M/L
- Removable hipbelt: No
- Seam-sealed: No
- Waterproof material: No
- Backpack frame: Aluminum frame
- Backpack padding: Yes
- Backpack removable frame: Yes
- Maximum load capacity: 20 kg
- Sex: unisex
- Material: 100D nylon honeycomb, 420D Oxford nylon
- Material composition: Nylon
- Dimension: 63 × 32 × 20 cm
- Volume: 60 l
- Weight: 1380 g
- Woocommerce product id: 94479
- Brand: Sierra Designs

## Variants

- Sierra Designs Flex Capacitor 40-60 – M/L · SKU 80710223PT-M/L · EAN 054003854344 · €210.90 · Out of stock · Black, M/L
- Sierra Designs Flex Capacitor 40-60 – S/M · SKU 80710223PT-S/M · EAN 054003854320 · €210.90 · Out of stock · Black, S/M

## Related

- [Hyberg BANDIT](/p/hyberg-bandit.md)
- [Sierra Designs Flex Capacitor Rain Cover](/p/sierra-designs-flex-capacitor-rain-cover.md)
- [Granite Gear Crown3 60 Women's](/p/granite-gear-crown3-60-womens.md)
- [Sierra Designs Flex Capacitor Replacement Hip Belt](/p/sierra-designs-flex-capacitor-replacement-hip-belt.md)
- [Granite Gear Crown3 60](/p/granite-gear-crown3-60.md)
- [Sea To Summit Mesh Stuff Sack 2023](/p/sea-to-summit-mesh-stuff-sack-2023.md)
- [Liteway Biggie Pack X-Pac 45 L](/p/liteway-biggie-pack-x-pac-45-l.md)
- [Liteway Hip Belt Pokkie X-Pac](/p/liteway-hip-belt-pokkie-x-pac.md)

## Shipping and returns

- [Shipping and payment](/shipping-payment)
- [Returns](/return-order)

## Images

- ![Sierra Designs Flex Capacitor 40-60 L](https://media.gramino.com/medusa/7fd4b1101eea07f9ccf583fcb5e12b12-01KWHVJCFFCXTJ9N7Y39WY2ZZG.webp)
- ![Sierra Designs Flex Capacitor 40-60 L](https://media.gramino.com/medusa/6e731554eacf7a56b7181d405b3bd017-01KWHVJCHYC8N3WWBGXC80XNE1.webp)
- ![Sierra Designs Flex Capacitor 40-60 L](https://media.gramino.com/medusa/afa36297d1837685d791a87a297a61f8-01KWHVJCQDAD9Q5MM5PPV96VMR.webp)
- ![Sierra Designs Flex Capacitor 40-60 L](https://media.gramino.com/medusa/0ee8bde84832ed87873b391f513348e5-01KWHVJCQ9N5WV6PVD7BPTNQ88.webp)
- ![Sierra Designs Flex Capacitor 40-60 L](https://media.gramino.com/medusa/7f67eb9d2b6b4af43a0d4421f97d6d05-01KWHVJCQQJAHVC1FPBYMJSRQ4.webp)
- ![Sierra Designs Flex Capacitor 40-60 L](https://media.gramino.com/medusa/1c9e5e44fa587ca712dd50f38035bc5a-01KWHVJCQSHDMXRFW2D5DNDFPZ.webp)
- ![Sierra Designs Flex Capacitor 40-60 L](https://media.gramino.com/medusa/7475ec92a837b2ac92ac4690116dbd27-01KWHVJCQNVEDVCJGAQDVMPF9F.webp)
- ![Sierra Designs Flex Capacitor 40-60 L](https://media.gramino.com/medusa/ec1863668db2f06c4d5e0d319512ec62-01KWHVJCVEZA70PAAMTDWCKH00.webp)

## Identifiers

- SKU: 80710223PT-M/L
- EAN: 054003854344
- Handle: sierra-designs-flex-capacitor-40-60-l
- Brand: Sierra Designs

This product is also available as [HTML](/p/sierra-designs-flex-capacitor-40-60-l).

Category: [Backpacks](/c/backpacks.md) · [Sitemap](/sitemap.md)

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