Bowflex’s adjustable kettlebell provides a useful weight range in a compact package, but it’s not perfect…

For a full roundup check out the best kettlebells for home workouts

Bowflex SelectTech 840


Top view of Bowflex SelectTech adjustable kettlebell

The Bowflex selection dial is impossible to miss, but can be difficult to move too

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  • Easy weight selection
  • Cast iron build quality
  • Consistent shape


  • Little room under handle
  • Selection dial is stiff
  • Bulky feeling

Grip: 3/5
Weight range: 4.5/5
Ease of adjustment: 4/5
OVERALL: 3.5/5

Bowflex is an established name in the adjustable free weights game, offering the excellent SelectTech 552i and SelectTech 1090i dumbbells that offer a massive spread of weights in a compact and space-saving package.

They’ve repeatedly ranked among the best adjustable dumbbells money can buy, so I had high hopes for the Bowflex SelectTech 840 Adjustable Kettlebell when it arrived. 

Managing to cram six weights into one compact system, the Bowflex SelectTech 840 allows for rapid weight adjustment on the fly, while the innovative design means that when you swap weights, you don’t change the overall shape of the kettlebell.

That was an issue with the Primal Personal Series Adjustable Kettlebell, resulting in a lack of consistency in the shape and feel of the kettlebell during a workout. No such issues here though.

Bowflex SelectTech 840 Adjustable Kettlebell features

Like other Bowflex adjustable systems, the SelectTech 840 Adjustable Kettlebell sits atop a small plastic tray that effectively ‘catches’ the weight plates that are stored inside the reinforced plastic exterior of the kettlebell itself.

An oversized dial on top of the unit acts selects the weight, twisting an internal spindle that locks onto the numerous weight plates. This offers the option of 3.5, 5.5, 9, 11, 16 or 18kg (or 8lb to 40lb, hence the ‘840’ in the name).

That’s a very useable weight spread, with the 18kg top end certainly feeling heavy enough for even advanced kettlebell users. 

Compared to other adjustable kettlebells I’ve tested, the Bowflex model feels a bit bulkier and takes up more room than, say, the aforementioned Primal Personal Series. There’s not a huge amount in it, but something to consider if you are looking to cram it in a cupboard or under the bed. Plus, the body isn’t sculpted like the Primal, so there’s no comfy groove when resting the kettlebell against your skin – as you would during overhead presses etc.

Bowflex SelectTech 840 Adjustable Kettlebell build quality 

There’s certainly a lot of plastic involved in this adjustable kettlebell, and it doesn’t feel as sturdy as the solid metal options we’ve tested. In fact, look closely at the weight selection dial and you’ll notice the words ‘Do Not Drop’ have been embossed into the plastic surface. I’m sure that’s something that wouldn’t end well.

If you’re looking for an adjustable kettlebell to beat up, this definitely isn’t the one. What’s more, the bottom of the kettlebell is effectively exposed once you lift it from its plastic tray. Should the internal locking mechanism fail, weight plates are going to fly out of there with the first aggressive swing. Just something to bear in mind.

Close-up of a man lifting a Bowflex adjustable kettlebell

The Bowflex case is studier than it looks but it is a little bulky

Thankfully, Bowflex has opted for a steel handle, which gives some peace of mind when throwing around 18kg of weight. It’s sturdy but it’s also a little on the thin side and lacks any kids of rubberised coating, so grip can be an issue if you suffer from sweaty palms.

The oversized selection dial on top of the kettlebell requires a significant amount of heft to spin – perhaps a little too much. It spins 360 degrees, so you can quickly swap from the heaviest to the lightest weight selection in a single click. 

However, I found the chunky dial leaves little room between it and the handle, which proves uncomfortable when standing in the front rack position, or when performing snatch movements.

Bowflex SelectTech 840 Adjustable Kettlebell performance

I tested the Bowflex SelectTech 840 Adjustable Kettlebell during one of the kettlebell-specific workouts found on the JRNY app. Bowflex customers get two months free with certain purchases, so I thought I’d give it a go.

Firstly, these adjustable models are a godsend if you’re tight on space. Rather than requiring an entire rack of kettlebells, you can have a useable weight spread in one compact unit. If, like me, you’re working out in a living room or a bedroom, the ability to quickly swap weights without the demand on real estate is well worth the initial investment.

The only downside to the Bowflex SelectTech 840 Adjustable Kettlebell is the workout feel. It just can’t compete with traditional kettlebells, simply because the exterior is bulky and, quite frankly, the wrong shape.

I found the handle to be shallow, with my wrists bashing off the chunky weight selection dial on a number of occasions. It’s also thin and gets slippery as hands start to sweat, while the bulky exterior makes snatches and the rack position a little awkward.

Seeing as the interior locking pin holds on to individual weight plates, there is understandably some rattling from inside when you start swinging. It’s nothing major, but can be disconcerting when you are swinging like a maniac in front of your brand new flatscreen television.

Despite the reliance on plastics, I found the Bowflex SelectTech 840 Adjustable Kettlebell to be fairly robust and able to withstand a bit more abuse than it lets on. The hard plastic shell will fend off the odd bump and scrape, but I’d be hesitant to ignore the ‘Do Not Drop’ warning, purely because the locking mechanism is likely to suffer… and with disastrous results.

Should you buy the Bowflex SelectTech 840 Adjustable Kettlebell?

If the Bowflex SelectTech 840 Adjustable Kettlebell is only available at the full price of £339, we’d struggle to recommend it, purely because there are rivals that offer a similar spread of weights in a more robust and easier to use package. However, these often have a hefty amount of money slashed off these days, making them something of a home gym bargain, if you can live with its quirks.

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