Creator verdict: RecommendsNÜOBELL 580 Adjustable Dumbbells
Head-to-head · Dumbbells & Kettlebells
NÜOBELL 580 Adjustable Dumbbells vs BowFlex SelectTech 840 Adjustable Kettlebell
Which should you buy in 2026? FR Scores, specs, prices and 7 independent video reviews, side by side.
FR Score 8.6 out of 10, Excellent
Twist-to-select speed and a true dumbbell feel, from 5 to 80 lb.
Typical price · 80-lb pair at NÜO’s list price; 50-lb pair about $599
FR Score 8.3 out of 10, Great
Six kettlebells in one: dial from 8 to 40 lb in seconds.
Typical price · Single adjustable kettlebell (8–40 lb) at BowFlex.com
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The quick verdict
NÜOBELL 580 Adjustable Dumbbells edges ahead with an FR Score of 8.6 vs 8.3, winning on build quality & durability, performance & feel and ease of use & footprint. It’s our Best Premium, while SelectTech 840 Adjustable Kettlebell is our Best Kettlebell. SelectTech 840 Adjustable Kettlebell is the cheaper pick by about $620.
Choose 580 Adjustable Dumbbells if…
- Feels closest to a fixed dumbbell, with flat heads and a knurled aluminum handle
- Twist-handle changes rank among the fastest in the category
- Wide 5–80 lb range in even 5-lb steps
Choose SelectTech 840 Adjustable Kettlebell if…
- One dial covers six weights from 8 to 40 lb
- Fastest weight changes of any kettlebell style
- Reasonably priced at about $149
Scores
Score breakdown
Each criterion scored 0–10 by our methodology. The winner of each row is highlighted.
Criterion580 Adjustable DumbbellsSelectTech 840 Adjustable Kettlebell
FR Score (overall)
Build Quality & Durability
Performance & Feel
Ease of Use & Footprint
Value for Money
Typical price
Video reviews
Specs
Specs side by side
| Spec | 580 Adjustable Dumbbells | SelectTech 840 Adjustable Kettlebell |
|---|---|---|
| Weight range | 5–80 lb per dumbbell | 8–40 lb |
| Increments | 5 lb (16 settings) | — |
| Adjustment | Twist handle in cradle | Dial selector with storage base |
| Replaces | 16 pairs of dumbbells | 6 kettlebells |
| Plates | Powder-coated cast iron | — |
| Handle | Knurled anodized aluminum, 1.26 in diameter | — |
| Internal components | ABS and nylon polyamide | — |
| Warranty | 2 years (per official Amazon listing) | 2 years |
| Sold as | Pair with cradles | — |
| Weight settings | — | 8, 12, 20, 25, 35 and 40 lb |
| Handle diameter | — | 28 mm |
| Shell | — | Plastic composite over metal plates |
| Model number | — | 100790 |
580 Adjustable Dumbbells: pros & cons
- Feels closest to a fixed dumbbell, with flat heads and a knurled aluminum handle
- Twist-handle changes rank among the fastest in the category
- Wide 5–80 lb range in even 5-lb steps
- Owners with four to five years of use still recommend them
- Premium price: about $769 for the 80-lb pair
- Plastic internal parts are the known weak point; not drop-safe
- 5-lb jumps are coarse for light isolation work
- Tops out at 80 lb per hand
SelectTech 840 Adjustable Kettlebell: pros & cons
- One dial covers six weights from 8 to 40 lb
- Fastest weight changes of any kettlebell style
- Reasonably priced at about $149
- Compact footprint for apartments and small gyms
- Plastic shell isn't meant to be dropped
- Taller, more oval shape than a traditional kettlebell
- 28 mm handle is thinner than standard bells
- 40-lb maximum is light for stronger lifters
On video
What reviewers say
Creator verdict: RecommendsNÜOBELL 580 Adjustable Dumbbells
Creator verdict: RecommendsBowFlex SelectTech 840 Adjustable Kettlebell
Creator verdict: RecommendsBowFlex SelectTech 840 Adjustable Kettlebell
580 Adjustable Dumbbells vs SelectTech 840 Adjustable Kettlebell: FAQ
Is NÜOBELL 580 Adjustable Dumbbells better than BowFlex SelectTech 840 Adjustable Kettlebell?
NÜOBELL 580 Adjustable Dumbbells scores higher overall (8.6 vs 8.3 out of 10), winning on build quality & durability, performance & feel and ease of use & footprint. SelectTech 840 Adjustable Kettlebell still has the edge on value for money.
Which is cheaper, 580 Adjustable Dumbbells or SelectTech 840 Adjustable Kettlebell?
At typical prices, BowFlex SelectTech 840 Adjustable Kettlebell costs about $620 less ($769 vs $149). Sizes and deals vary, so check the current price at the retailer.
Which has more video reviews?
We’ve cataloged 4 independent video reviews of 580 Adjustable Dumbbells and 3 of SelectTech 840 Adjustable Kettlebell. Both products’ pages list every review with the creator’s verdict.