The Bowflex SelectTech 840 is a single kettlebell with a dial that selects one of six weights between 3.5 kg and 18 kg, according to Bowflex. It suits a buyer who wants several weights in a 22.4 x 17.8 cm footprint and accepts an 18 kg top setting, and suits less well anyone expecting to progress beyond it.
What weights does the Bowflex SelectTech 840 offer?
Bowflex lists six settings: 3.5, 5.5, 9, 11, 16 and 18 kg (8, 12, 20, 25, 35 and 40 lb). The manual says these are estimated values and can vary because of manufacturing variances. This page reviews the product from Bowflex's UK product page and owner's manual, not from testing.
The manual's parts list gives five plates of 4, 8, 5, 10 and 5 lb, and says the handle alone represents the 8 lb (3.5 kg) starting weight. Adding the plates in that order gives 12, 20, 25, 35 and 40 lb, which matches the six settings. That is arithmetic from the manual, not a maker statement, but it explains why the steps are uneven.
What the maker says it is
Bowflex describes the SelectTech 840 as replacing six kettlebells, with a weight selection dial. The product page also lists on-demand workouts through the JRNY app, including trainer-led classes designed for SelectTech kettlebells, and a JRNY adaptive fitness membership. The page does not state the membership price or terms, so check that before counting it as part of the value.
Specification
| Item | Maker's figure |
|---|---|
| Weight settings | 3.5, 5.5, 9, 11, 16 and 18 kg (8, 12, 20, 25, 35 and 40 lb) |
| Plates (manual) | 4, 8, 5, 10 and 5 lb, plus the handle |
| Adjustment | Rotating dial; the handle lifts out of the base |
| Dimensions | 22.4 x 17.8 x 31.8 cm (8.8 x 7 x 12.5 in) |
| Assembly weight (manual) | 18.4 kg (40.5 lb) |
| Warranty (product page) | 2 years on parts |
| Materials and handle diameter | Not published |
| Minimum age (manual) | Not intended for anyone under 14 |
| Use (manual) | Home use only; not outdoors or in moist or wet locations |
The maker's page does not state materials, handle diameter or what is in the box.
Who does the specification suit?
Six settings in one unit suit a household where more than one person will use the bell, or a buyer who wants a light bell to start and a heavier one later. The jumps are uneven: 11 kg to 16 kg is a 5 kg step while 9 kg to 11 kg is 2 kg. Anyone who progresses in small steps should look at that. The top setting is 18 kg, so a buyer who expects to need a heavier bell will want a second one. For other adjustable options see the best adjustable kettlebell guide.
How does it work, and what does that imply for space?
You pull the handle straight up out of a base and only the selected plates come with it. The manual says to use a vertical motion, perpendicular to the base, and not to tilt it or move it sideways until it is fully clear of the unselected plates. A locking mechanism lets the knob turn only when the handle is fully inserted, and is designed to lock the handle to the bottom plate if the weight has only been partly selected.
To lift the kettlebell and base together, the manual says to set the knob to the maximum weight and use the lift handles moulded into the base, not the handle. From the stated dimensions the unit covers about 22.4 x 17.8 cm of floor. That is reasoning from the figures, not a measure of how it stores in your room. For movement space the manual asks for a free area 0.6 m beyond the maximum reach of the exercise in all directions, and it advises putting the kettlebell directly on the floor. See the small apartment gym guide for layout ideas.
Does the Bowflex 840 need maintenance?
Yes, the manual asks owners to inspect the kettlebell before each use and to test the locking mechanism, suggesting a monthly repeat. The test has you turn the knob to 8 lb, withdraw the handle and check the knob will not turn, then reinsert the handle, set the knob between settings and check the handle will not lift out in that position. If it fails, the manual says to stop using the kettlebell until approved service is available.
Cleaning is simple: a cloth lightly dampened with warm water and a little mild soap, wiped dry. The manual says the unit is internally lubricated, allows only a silicone lubricant (preferably food grade) on the selector mechanism if you feel it necessary, and says not to use solvents, harsh detergents, chemicals or bleach.
What to check before buying
- Never drop it. The manual says dropping can damage plates and the lock, can cause plates to come off the handle without warning and voids the warranty. It also says not to lean on the handle or use it to support body weight, for example in a push-up.
- Not user serviceable. The manual says not to disassemble the handle or base. Outside the US and Canada, contact the local distributor.
- Warranty route in the UK. The manual's warranty section is headed for purchases in the US and Canada and says purchasers elsewhere should contact their local distributor. The UK product page lists 2 years on parts, so confirm with the seller who handles claims.
- Delivery and returns. The maker's page lists an approximate delivery of 28 days from order confirmation for credit card payments, a 7-day cooling-off period and written return requests by email. GOV.UK business guidance describes a 14-day cancellation right from delivery for distance sales, so ask the seller which applies. At the time of checking, the page showed the item as sold out.
- Health. The manual advises consulting a physician before starting an exercise programme. A qualified coach can advise on technique.
Is the Bowflex 840 suitable for children?
No, not according to the maker: Bowflex's manual says it is not intended for use by anyone under 14 years of age. It also says children must not be let on or near the machine, because moving parts and other features can be dangerous to children, and the warning label says to keep children and pets away at all times. It advises checking that your surroundings are free from interference and third parties before you start a workout.
Who should skip the Bowflex 840?
Skip it if you want a single weight above 18 kg, if you want no mechanism to test monthly, or if the household includes anyone under 14. Also skip it if you are buying for commercial use, as the manual says the product is for home use only and the warranty excludes commercial settings.
Alternatives
The PowerBlock Pro adjustable kettlebell uses a magnetic selector pin instead of a dial and lists 8 to 16 kg in its 18-35 lb model, with a 5-year warranty. If you would rather compare with fixed bells, see the best kettlebell guide and kettlebell vs dumbbell training. For dumbbells, the Bowflex SelectTech 552 uses the same brand's dial approach.
Price context
Around £199 (checked Oct 2026). The maker's own page lists different prices from that figure, so check the current price with the seller before buying.
