CORE Duffel Large 51L
Man wearing large green CORE Duffel over shoulder inside gym setting
CORE Duffel Large 51L
Side view of large green CORE Duffel showing matching weight lifting belt stored inside belt sleeve
Side view of large green CORE Duffel
Flat lay of large green CORE Duffel surrounded by gym gear that fits inside duffel bag
Birds eye view of divider system inside of large green CORE Duffel packed with gym gear
Birds eye view of empty large green CORE Duffel, showing internal pockets and compartments
Birds eye view of large green CORE Duffel packed with gym gear
NOBULL sneakers packed inside large green CORE Duffel shoe compartment
Water bottle and shaker bottle packed inside large green CORE Duffel bottle pockets
Close up of large green CORE Duffel zippers and buckles
Man holding large green CORE Duffel by handles
CORE Duffel Large 51L
Medium and large CORE Duffel stacked on top of each other, showing size difference
Side by side of large and medium CORE Duffel showing size difference

CORE Duffel Large 51L

4.8
Rated 4.8 out of 5 stars
4.8 Stars (1,074 Reviews)
$200
Size: Large 51L
Mini 15L
Mini 15L
Medium 35L
Medium 35L
Large 51L
Large 51L
Color: Green
Desert
Desert
Black
Black
Green
Green
Natty
Natty
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Duffel Divider
Duffel Divider
$40 $50
Matching Lifting Belt
Matching Lifting Belt
$40 $60
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DEDICATED LIFTING BELT STORAGE

  • External weightlifting belt attachment
  • 13/15” Internal laptop sleeve
  • Sealed internal shoe compartment
  • Dual bottle pockets 

Do you even lift? If so, meet your new favorite lifting partner. Say goodbye to your belt taking up precious space in your bag, with this unique and specially designed lifting belt attachment that ensures functionality isn’t compromised whatsoever. The CORE Duffel is made to store everything you need and support you every time you step into the gym.

(Lifting belt sold separately)

Covered by our guarantee to be free of defects in material or workmanship. If there is a defect in materials or workmanship KNKG will repair or replace your bag.

Our bags are meticulously designed to stand up to the test of time. We utilize durable materials, coupled with top-notch craftsmanship and rigorous testing, resulting in the toughest bags in the game. You can confidently pack your bag to its maximum capacity without worrying about it stretching or tearing.

The CORE Duffel is made from:

  • 500D nylon body material (PVC backing)
  • YKK zippers
  • Powder-coated steel buckles
  • Ripstop nylon lining
  • Nylon webbing
​
CORE DUFFEL
SIZE COMPARISON
Capacity
Bag Weight
Height (H)
Width (W)
Depth (D)
Shoe Storage
Laptop Sleeve
Lifting Belt Size
MINI
15 L / 4 GAL
0.6 kg / 1.3 lbs
23cm / 9.1"
38cm / 15"
18cm / 7.1"
Not recommended
iPad
KNKG Belt
MEDIUM
35 L / 9.2 GAL
0.8 kg / 1.8 lbs
28cm / 11"
45cm / 17.7"
28cm / 11"
Size 10
Up to 13"
6.3" (W) - 45.7" (L)
LARGE
51 L / 13.4 GAL
1 kg / 2.2 lbs
32cm / 12.6"
50.8cm / 20"
32cm / 12.6"
Size 13
Up to 15"
6.7" (W) - 51.5" (L)
Capacity
Bag Weight
Height (H)
Width (W)
Depth (D)
Shoe Storage
Laptop Sleeve
Lifting Belt Size
MINI
15 L / 3.96 GAL
0.6 kg / 1.3 lbs
23cm / 9.1"
38cm / 15"
18cm / 7.1"
Not recommended
iPad
KNKG Belt
MEDIUM
35 L / 9.2 GAL
0.8 kg / 1.8 lbs
28cm / 11"
45cm / 17.7"
28cm / 11"
Size 10
Up to 13"
6.3" (W) - 45.7" (L)
LARGE
51 L / 13.4 GAL
1 kg / 2.2 lbs
32cm / 12.6"
50.8cm / 20"
32cm / 12.6"
Size 13
Up to 15"
6.7" (W) - 51.5" (L)

Designed for weightlifting.

Workouts are tough but these bags are tougher. Effortless to carry and palpably robust. This thing does it all and measures in at the perfect size.

Designed for serious lifters who crave serious organization.

This is the best gym bag for powerlifters. Many amazing features that set this bag apart from its rivals. The outer material is tough, durable, and lightweight while also being water resistant and easy to clean.

Made for maxing.

FAQS

The main difference is the unique weightlifting belt attachment. This feature allows the bag be used as normal, while carrying a cumbersome lifting belt on the outside. Other changes are the volume (35L) and the layout.

Most of the materials are the same as used in other KNKG bags. YKK zippers, heavy duty buckles, nylon lining and webbing are all the same. In the CORE range, we have gone for a lighter 500D nylon outside and a new velcro logo feature that allows you to go 'incognito' with your own patches.

Measure the widest point of your belt and its length.

The CORE35 (medium) duffel can fit a belt up to 6.3"/16cm wide and 45.7"/116cm long.
The CORE51 (large) duffel can fit a belt up to 6.7"/17cm wide and 45.7"/116cm long.

A lever belt can fit, but you should count the lever into your measurement.

The CORE35 (Medium) will fit size 10 shoes. The CORE51 (Large) will fit size 13 shoes. Larger shoe sizes will fit our PLUS Duffel.
4.8
Rated 4.8 out of 5 stars
Based on 1,074 reviews
Total 5 star reviews: 948 Total 4 star reviews: 98 Total 3 star reviews: 12 Total 2 star reviews: 4 Total 1 star reviews: 12
97%would recommend these products
Slide 1 selected
1,074 reviews
  • EE
    Eric E.
    Verified Buyer
    Reviewing
    CORE Duffel Medium 35L
    I recommend this product
    What type of training is your KNKG bag supporting you with? Weightlifting, Other
    Using For: Gym Bag, Sport / Fitness
    Rated 5 out of 5 stars
    Awesome gym bag

    This is excellent for storing both gym equipment and some of my ballroom dance stuff! It was previously really annoying, though possible, to sift through things in a smaller bag. I love the material, pockets, etc. Highly recommend for the price!

    Was this helpful?
  • SA
    Steven A.
    Verified Buyer
    Reviewing
    CORE Duffel Mini 15L
    I recommend this product
    What type of training is your KNKG bag supporting you with? Weightlifting
    Using For: Gym Bag
    Rated 5 out of 5 stars
    Finally a Duffle that actually gets it!

    Ive gone through a lot of gym bags over the years, but the CORE Duffel Mini 15L genuinely feels like it was built with intention. It’s compact, but somehow still fits everything I actually need—no wasted space, no bulk.

    What really stands out is how functional it is. The dedicated lifting belt sleeve alone sets it apart, and the multiple compartments make staying organized effortless. It’s clear this bag wasn’t just designed to look good—it was designed for real use on the gym floor.

    The build quality is on another level too. It feels tough, structured, and made to last, like it can handle daily wear without breaking down. You can tell right away this isn’t a throwaway bag—it’s something you rely on.

    Overall, it delivers exactly what it promises: a compact, no-BS duffel that’s loaded with function and built for people who actually train. Easily one of the best gym bags I’ve owned.

    Was this helpful?
  • EM
    eddie m.
    Verified Buyer
    Reviewing
    CORE Duffel Medium 35L
    I recommend this product
    What type of training is your KNKG bag supporting you with? Weightlifting, Functional Circuit Training
    Using For: Gym Bag
    Rated 5 out of 5 stars
    Excellent Bag

    Great color, well made. Best gym bag ever. Has plenty of storage. Design for shoe storage outstanding

    Was this helpful?
  • SC
    Samuel C.
    Verified Buyer
    Reviewing
    CORE Duffel Medium 35L
    I recommend this product
    What type of training is your KNKG bag supporting you with? Weightlifting
    Using For: Gym Bag, Every Day Carry, Work
    Rated 5 out of 5 stars
    Great size

    Stores everything I need for my workout and going to work afterwards: Clothes, shakes, food, shoes. Nice and durable. Cleans easy and a little bit of rain just rolls right off of it. Very happy with the purchase 👍

    Was this helpful?
  • VM
    Victor M.
    Verified Buyer
    Reviewing
    CORE Duffel Large 51L
    I recommend this product
    What type of training is your KNKG bag supporting you with? Weightlifting
    Using For: Work, Gym Bag, Sport / Fitness
    Rated 5 out of 5 stars
    Fire Fighter

    bought this to keep all my fitness gear together and it fits so much gear. Great for when i travel from home gym to Station gym and different Station assignments. I love it so far. Get a bit of grief for having such a huge bag for a dude that stands at 5'3'' but i could care less, the material is as thick as my skin and just as durable.

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