Technical Details

How are the steel bands attached to the ABS grip?
They aren't attached;The support bands are a single piece of laser cut spring steel bent to track through the internal channel of the heavy duty ABS grip- You cannot pull them out. Immensely strong. In the lower portion of the handle (above), the channels are widened to allow for flexing of the support bands, providing compliance for varying stack widths and a slight bit of shock absorption.

When it comes to the the design and engineering quality of our product Kettlestack customers care almost as much as we do ourselves; If you don't see your question (and answer) among the most likely questions, just get in touch and we'll sort it out.

How are the steel bands attached to the ABS grip?
They aren't attached;The support bands are a single piece of laser cut spring steel bent to track through the internal channel of the heavy duty ABS grip- You cannot pull them out. Immensely strong. In the lower portion of the handle (above), the channels are widened to allow for flexing of the support bands, providing compliance for varying stack widths and a slight bit of shock absorption.

Did you say ABS handle , how strong can that be?

We use high impact ABS polymer (the same stuff used in football helmets) in the Kettlestack design. We specify 5/32" material with a highly redundant internal web design; The ABS is for your hand's benefit, the Kettlestack relies on spring steel for it's strength.

We have even dropped a 55 lb configuration from a 30" desktop; It landed right on the handle without any damage. However, we do not recommend and cannot (fully) warrantee improper use such as a drop.

What about the bolts, won't they snap off ?

The Kettlestack design uses 1/2" grade 8 or better bolts (with a shear capacity of over 15,000lbs) to hold either of the wings and a large 4" steel hexnut of similar strength for the center core.


or loosen accidently ?

A subtle point; The two-band separation tapers- wider than the hexnut span at the root (near the handle) and narrower at the tip. The spring steel support band, in the manner of a good mortise and tenon joint, distribute the compression from the tightened bolts entirely across the band faces- regardless of the width of the central weight stack. We've never seen properly tightened bolts (at least 7 turns) work loose. However, we've deliberately loosened the bolts and the rattle and different feel immediately gets your attention.

Do the bands adjust to accomodate lighter/fewer weights without the weight plates sliding around?

Yes. Since the bands flex inside of the handles, they can flex to accomodate different core widths- Checkout this animation and you'll see 'cores' with 4 or 5 plates. Once you crank the bolts down, it's tight .

Why is there a washer welded to one end of that hexnut axle ?

Glad you noticed:

* If there wasn't a captive washer, tightening the bolts could shift the positition of the hexnut. In the worst case (impossible with the washer) you'd lose track of the axle's true position and have a false notion of how many turns were applied to the bolts.
* You can quickly adjust or remove the weights on the 'washer side' and the remaining weights in the central and opposite stack are still completely fixed.
* By allowing one or two bolts Kettlestack adjustable kettlebell handles provide a wide range of stack widths. You get the shape and weight you want.
* Safety and very quick weight adjustments.


Is the axle aluminum ?

The axle is steel- always has been. Did some shill for the cast kettlebells start a rumour ?

The only thing more foolish than an aluminum axle would be using a cheap, "paper clip" steel for the support bands. It's expensive, but Kettlestack uses expensive tempered steel bands. Anything else would be irresponsible :

* We invented this concept
* We use these things
* thousands of units testify to their sturdiness .

What about "plate showers" ?
Cute phrase by some die hard cast KB advocates.

Watch this 70lb Kstack dropped almost 7ft onto a 500lb steel crash plate-no padding (btw we still use this "veteran" all the time).

Any questions ?