JAXJOX DumbbellConnect Vs Bowflex SelectTech 552: Which Brand Can Claim To Make The Best Adjustable Dumbbell?

JAXJOX DumbbellConnect and Bowflex SelectTech 552
(Image credit: Harry Bullmore / Future)

If you’re tired of spinning plate wheels to do your home workouts, upgrading from those spinlock dumbbells to a selectorized adjustable set might be what’s needed. 

Selectorized dumbbells allow you to change their weight in seconds to suit your strength level and the exercise you’re doing. They also offer the versatility of a weight rack while taking up the same floor space as a shoebox. 

The JAXJOX DumbbellConnect and Bowflex SelectTech 552 are two of the most popular options in our selection of the best dumbbells. JAXJOX’s set are the first digital dumbbells, allowing you to change weight with the touch of a button, and link to an app for rep-counting, average power data and more. Bowflex keeps things simpler with its sturdy dial-controlled dumbbells.

But which set should you buy? We’ve explored their similarities and differences to help you decide which would suit you best. 

Price And Availability

JAXJOX DumbbellConnect and Bowflex SelectTech 552

(Image credit: Harry Bullmore / Future)

The Bowflex SelectTech 552s cost $429 on the company’s website, although other retailers frequently offer discounted deals. In the UK, the dumbbells are widely available online for £399.99.

The JAXJOX DumbbellConnect has an MSRP of $499.99 in the US and £499.99 in the UK. At the time of writing, the set had recently been the subject of major discounts, including a price reduction at Best Buy that saw them available for $99.99. However, on that retailer’s site and the company’s website the weights are out of stock. In the US, one of the few retailers it was still available from was Dick’s Sporting Goods, which had a pair for its retail price of $499.99. 

How I Tested These Adjustable Dumbbells

I’ve owned both sets of dumbbells for nearly a year, using them for home hypertrophy training workouts and accessory exercises to complement my gym efforts. I have also used both for all four sessions (chest and back, arms, legs and abs, and shoulders) in our dumbbell workout plan. This involves pressing them overhead, popping them in a goblet hold, gripping them in a farmer’s carry position for lunges, hammering out spider curls and more. It has allowed me to understand how these free weights feel for various bodybuilding movements. 

Weight Range

The Bowflex SelectTech has 15 weight options, from 5-52.5lb (2.2-23.8kg), while the JAXJOX DumbbellConnect has eight weight options, covering a range of 8-50lb (3.6-22.6kg). 

The greater number of weight settings on the Bowflex dumbbells is an advantage for all lifters because it allows them to add a couple of pounds to lifts at a time as they grow stronger. The JAXJOX DumbbellConnect set has 8lb jumps between the different load options. If doing a lighter exercise such as the lateral raise, you may find that 8lb is too light but 16lb feels too heavy—it’s harder to find a setting that’s just right.


JAXJOX DumbbellConnect and Bowflex SelectTech 552

(Image credit: Harry Bullmore / Future)

The Bowflex SelectTechs have bulky plastic-finished plates with large gaps between them. The rubber grips are garish, with the Bowflex logo splattered across them. In contrast, the JAXJOX DumbbellConnect set has a sleek silhouette, with the matte-gray plates slotting snugly into place either side of a knurled metal grip. 

The interlinked plates of the DumbbellConnects have a more solid, secure feel, which didn’t move or rattle during any bodybuilding movements. The medium knurling of the handle also offered good grip, even with sweaty hands. The slim plates also make it compact, so I found it easier to handle than chunkier rivals. 

The Bowflex SelectTechs did, however, perform well. Despite the plastic finish of the plates, they feel robust. The plates moved slightly during more explosive exercises, but I was never worried they would come loose. The sizable dimensions of the plates and central handle meant it felt cumbersome at times, particularly for exercises like biceps curls. But, for most muscle-building movements it allows a full range of motion. 

Weight-Changing Mechanism

The major difference between the two sets of dumbbells is that one is digital, while the other provides a more conventional selectorized option. 

The digital JAXJOX DumbbellConnect is the first of its kind, offering the chance to change the weight using + and – buttons on a docking tray. Once you’ve selected your load of choice (which will be displayed on a small screen between the buttons), you take the dumbbell out of the docking tray, and any plates that are surplus to requirements will be disconnected and left behind. 

You can also link the dumbbells to the JAXJOX app on your phone to track data such as sets, reps and average power, as well as on-demand workout classes (if you pay a monthly subscription fee). I must admit, in the year I’ve had them I’ve only ever used the app to play around with while testing the dumbbells.

JAXJOX DumbbellConnect and Bowflex SelectTech 552

(Image credit: Harry Bullmore / Future)

The Bowflex SelectTech 552s use a dial on either end to allow you to change the weight. Place the dumbbells in their docking trays and twist the dials to the weight you want, which will be signaled by markers. Then, as with the DumbbellConnects, lift them out of the docking trays to shed any unneeded plates.

Both weight-changing mechanisms are faster than switching the load of a spinlock dumbbell set – the task is complete in a matter of seconds. The JAXJOX set takes marginally longer as you have to wait for them to register your choice of weight. 

A downside of the JAXJOX set is that the docking tray needs to be charged to change the weight. If you work out in a garage without a power outlet, you will have to remember to juice them up. A single charge will last several days, though.

The main drawback of the Bowflex dumbbells is, unlike other models I’ve tried from the likes of Ativafit and Core Home Fitness, you have to change dials on both sides to get the weight you want. This takes longer, and creates the possibility that you’ll load the dumbbells unevenly mid-workout. 

Why You Should Buy The JAXJOX DumbbellConnect Instead Of The Bowflex SelectTech 552

Both sets are simpler to use than spinlock dumbbells but, because you have to change dials on both ends of the Bowflex set, I think JAXJOX has the easier method. It also avoids the possibility of loading the dumbbells unevenly, which has happened to me on occasion while using the Bowflex set.

What really swings it for the JAXJOX is the design. The Bowflex set is clunky and the plates have a wide diameter that knocked into me during exercises like biceps curls. The plates feel secure, but do move a little when lifted. The plastic coating gives them a cheaper overall feel.

JAXJOX DumbbellConnect and Bowflex SelectTech 552

(Image credit: Harry Bullmore / Future)

The JAXJOX set has a sleek, matte-gray finish. The plates are slimmer and not as wide, making them easier to handle. The plates have built-in grooves designed to fit so that you don’t get unwanted movement or rattling.

The central handle on the JAXJOX has medium knurling for great grip. Plastic buffers on either end also mean, unlike the Bowflex, they can be held comfortably in a goblet position or for movements like triceps extensions.

Why You Should Buy the Bowflex SelectTech 552 Over the JAXJOX DumbbellConnect

The JAXJOX DumbbellConnect has eight weight options, from 8-50lb (3.6-22.6kg). The Bowflex SelectTech 552s improve on this with a range of 5-52.5lb (2.2-23.8kg), and also offer 15 different loads. If you’re looking to make incremental gains, or use these weights for lighter accessory movements like lateral raises, you may want to opt for the Bowflex.

If you like to lift heavy, the Bowflex dumbbells are also available in a heavier 9.9-90lb (4.5kg-41kg) option, although the price increases in line with the higher maximum load.

Another advantage the SelectTech dumbbells have over the DumbbellConnects is that they don’t rely on electricity. The JAXJOX docking stations need to be charged up to work and while the battery life is five days, it is frustrating if you forget to charge them and are left unable to change the weight. The Bowflex set, on the other hand, is mechanical, making it a good option for garage gyms where you might not have access to a mains socket.

Should You Buy The JAXJOX DumbbellConnect Or Bowflex SelectTech 552?

Both sets have advantages, but I feel the JAXJOX is the better option. The compact design looks, and lifts, better than the Bowflex SelectTech 552s. I found them more maneuverable and secure. The shape is also more practical for bodybuilding-style movements like the dumbbell bench press, dumbbell pull-over and goblet squat, making them a great option for strength training at home. 

Harry Bullmore
Staff writer

Harry covers news, reviews and features for Coach, Fit&Well and Live Science. With over a decade of training experience, he has tried everything from powerlifting to gymnastics, cardio to CrossFit, all in a bid to find fun ways of building a healthy, functional body.