NÜOBELL S 5100 Review: 100 lb Adjustable Dumbbells at a $999 Price
By The Ironnook Test Desk ·
8.0
nuoathletics.com
The verdict
The S 5100 is the adjustable dumbbell for lifters who miss the feel of a real one. Twist the handle and both ends change in a second, the shape stays compact enough for flyes, and 100 lb a hand covers serious pressing. It costs $999 a pair, the dumbbells are not meant to be dropped and the stand is fussy. Buy it if you lift heavy and have money. Otherwise PowerBlock or Bowflex do the job for less.
Best for: Heavy lifters who want one pair to replace a dumbbell rack
What we liked
Twist-handle change takes about a second
Range of 5 to 100 lb per dumbbell in 5 lb steps
Compact length of 548 mm, narrower than boxy rivals
Knurled aluminium handle with 32 mm diameter feels like a real dumbbell
Four-year residential warranty when bought direct
What could be better
$999 a pair, far above Bowflex SelectTech at roughly $549
The 552 is still the quickest dial dumbbell to use and the cheapest way to replace 15 pairs, but it asks for trust the brand has not fully earned. The recalled models dropped plates on people, the redesigned Results Series adds metal locking tabs, and the dial housing is still plastic. Buy it on sale, treat it kindly, and never drop it. If you lift heavy or rough, buy a PowerBlock or Nuobell instead.
These are the adjustable dumbbells for people who outgrew Bowflex. The all-steel build, the 34 mm knurled handle and the 125 lb ceiling feel like fixed dumbbells, and the lifetime warranty backs that up. They cost $899.99 for the 65 lb pair and $1,499.99 for the full 125 lb set, and the pop-pin changeover is slower than a dial. Heavy lifters should buy them. Anyone who stops at 50 lb should save about $700.
8.4$899.99 to $1,499.99 a pair
Weight on the handle can be off by up to 5%
Reviewers worry about plastic parts if dumbbells are dropped
Cradles need careful alignment and a floor stand costs $349 more
The NÜOBELL S 5100 runs from 5 to 100 lb per hand in 5 lb steps, changed by twisting the handle. It costs $999 a pair. We asked whether that feel justifies paying more than a pair of Bowflex.
Every adjustable dumbbell makes the same promise: a whole rack in the space of a shoebox. Most of them keep it by turning the dumbbell into something else, a block or a brick with a handle. The NÜOBELL S 5100 is the one that tries hardest to stay a dumbbell. It is also the one that asks for $999.
One twist, both ends
The mechanism is a patented twist handle. You rotate the handle collar to the weight you want, lift, and the plates you chose come with you. The maker lists a range of 5 to 100 lb per dumbbell in 5 lb steps. Reviewers agree it is fast. Garage Gym Reviews gave the earlier 80 lb model 4.75 out of 5 for adjustment speed, its best score, and other reviewers praise the way both ends change at once.
Speed matters in practice. A set of dumbbell rows into presses into curls means three weights in a minute. With dial or pin systems that interrupts your rest; here it is part of it.
Feel under load
A dumbbell is its shape. The S 5100 measures 548 mm long, 181 mm high and 200 mm wide with an aluminium handle 32 mm across. That is compact for a 100 lb dumbbell, and a comparison from GymScored says it wins on feel against Bowflex's boxier shape and PowerBlock's frame. The short length lets the dumbbells pass close to each other during flyes, where a longer bell would clash.
GymScored's 2026 guide, which scores eight adjustable sets on mechanism and build.
The handle is knurled like a barbell, and testers like the grip. At 100 lb a hand you can bench, press and row heavy. Few adjustable pairs go that high.
Where the doubts are
Three things bother us. First, the marked weight can differ from the true weight by up to 5%, says NÜO itself. That is a few pounds on a heavy pair, which is fine for training but not for a programme counting every 2.5 lb.
Second, durability. Garage Gym Reviews praised the build but said hard plastic connecting pieces raise questions about long-term use, and the dumbbells are not designed to be dropped. NÜO describes stainless steel V-connectors and plastic compounds placed against the metal for smooth, quiet changes, so the plastic is deliberate. If you slam bells down after a failed set, this is the wrong tool. A PowerBlock, with its simple proven design, is probably the tougher option.
Garage Gym Reviews rates the earlier NÜOBELL 80 at 4.3 out of 5, with a caveat on durability.
Third, the cradles. They come in the box, but the same tester said each dumbbell has to be seated precisely or it can stick. A floor stand called PYLON is $349 extra.
What $999 really compares with
A side-by-side article on Bowflex and NÜOBELL adjustable dumbbells.
GymScored lists the Bowflex SelectTech 1090 near $549 for 10 to 90 lb, and the earlier NUOBELL 80 at $745. The S 5100 adds 20 lb a side and costs $254 more than that 80. A fair way to think about it: it works out at roughly $5 per pound of range per pair. A Bowflex works out nearer $3.
Its extra is shape, speed and the top 20 lb. If you press under 80 lb, the cheaper pairs give you most of the benefit. Our Bowflex SelectTech 552 review covers the cheaper dial route.
Small-space maths
Where the S 5100 shines is floor space. Two dumbbells and their cradles replace twenty pairs of fixed ones, which at home means one corner of a garage or bedroom instead of a rack along a wall. For a lifter in a flat, that trade is the reason to pay a premium at all.
Warranty, delivery and the small print
NÜO gives two years as standard and an extra two if you buy direct, four in total for home use. Delivery is 3 to 5 business days in most countries and up to 8 for rural addresses. Read the returns page before ordering, since the product page did not spell out details.
Who should buy it
Buy the S 5100 if you lift heavy, press more than 80 lb a hand, hate how boxy dials feel, and treat the dumbbells like gear rather than weights to be thrown. It is the best-feeling adjustable pair we looked at.
Skip it if you are new to lifting, if you train hard enough to drop bells, or if $999 would be better spent on a bench and a rack. Then buy a PowerBlock or a Bowflex and keep the change.
The 840 is a convenient bell for beginners and small flats: six weights from 8 to 40 lb in one dial, with a smooth shell and a comfortable handle. It is not a replacement for cast iron. The plates rattle on swings, the body is bulky, 40 lb is a low ceiling, and $149 buys more iron elsewhere.
