This is the story of how I turned a 15" Titan adjustable dumbbell to be 80 cm (31.5 inch) long. Why? Because I have a space-constrained home gym but still wanted a leg press, and so I had to remove its original barbell.
In its place, I built a pair of wood mounts for a normal barbell to rest upon, covered in that earlier post. However, since this machine is wall-adjacent, such a barbell would have to fit inside the width of the leg press, so about 80 cm. But must also be wider than the spacing from outside-edge to outside-edge of the wood mounts, which is 60 cm.
Such a short barbell -- or long dumbbell -- does not readily exist commercially, with the narrowest one I've seen being 48 inch barbells, which are still too wide. So I decided to build my own, using my spare Titan dumbbell as the base.
To start, the Titan dumbbells are excellent in this capacity, as the shaft diameter is 28 mm -- not 32 mm as the website would indicate -- which is a common diameter, if I am to cut short a cheap barbell to replace this dumbbell's shaft.
In keeping with my preexisting frugality, I purchased a cheap 1-inch barbell, hoping that it adopts the Olympic 28 mm shaft diameter, and not the 29 mm deadlift bar shaft diameter, as the Titan collars have small clearances. Matching neither, I find that this bar is closer to 23 mm, which although will fit into the existing collars, poses its own issues.
Nevertheless, this 7 ft barbell can conveniently be cut in half to yield two 42 inch segments. And then the included bar stops can be loped off, and then the length further refined to 77 cm, thus hiding the marks from the bar stop within the Titan collars, and also centering the (meh) knurling from the cheap bar.
But perhaps a picture will be more explanatory. Here, the original collar is dismantled at the top, showing the original shaft with a groove cut into it, about 1/4-inch from the end. Into that groove would fit two half-rings with an inner diameter of 20.4 mm and an outer diameter of 40 mm. In fact, all the parts inside the collar use 40 mm outer diameter, except the spacer cylinder, which is smaller at 37 mm. All of these parts are held captive within the collar using the C-ring and the geometry of the collar itself.
To deal with the difference between the collar expecting 28 mm, and the cheap bar's 23 cm, I designed an ABS 3d printed part in FreeCAD to act as a bushing, upon which the original Titan brass bushing will ride upon. This ABS bushing is held captive by way of its center bulge, which fits within the dead space inside the collar.
As for how I cut the groove into the end of the new shaft, I still don't own a lathe. So the next best is to mount an angle grinder onto a "cross slide vise" taken from a drill press, with the shaft secured in a wooden jig to only allow axial rotation manually. The vise allows precision control for the cutting wheel's depth, with me pausing frequently to measure how close the groove is to the desired 20.4 mm inner diameter. This is.... not a quick nor precise process. But it definitely works.
After reassembling both collars onto the new shaft and lubricating with white lithium, the final result is a long dumbbell (or short barbell) with Titan's 3.5 inch collars on the end, with 63 cm of shaft exposed and 80 cm from end to end. The ABS bushing is remarkably smooth against the brass bushing, after some sanding with 180 grit. The whole dumbbell weights 5.48 kg empty.
Here is the comparison with the stock Titan dumbbell. It's pretty amazing how the knurling conveniently lined up. It fits well onto the wood mounts of the leg press.
But why would I do all this just to add a weirdly long 3.5-inch collar dumbbell to a leg press, when it already can accept weights underneath the carriage? I will answer that in a follow-up post.
Notwithstanding the possible typo in the title, I think the question is why USA employers would prefer to offer a pension over a 401k, or vice-versa.
For reference, a pension is also known as a defined benefit plan, since an individual has paid into the plan for the minimum amount will be entitled to some known amount of benefit, usually in the form of a fixed stipend for the remainder of their life, and sometimes also health insurance coverage. USA's Social Security system is also sometimes called the public pension, because it does in-fact pay a stipend in old age and requires a certain amount of payments into the fund during one's working years.
Whereas a 401k is uncreatively named after the tax code section which authorized its existence, initially being a deferred compensation mechanism -- aka a way to spread one's income over more time, to reduce the personal taxes owed in a given year -- and then grew into the tax-advantaged defined contribution plan that it is today. That is, it is a vessel for saving money, encouraged by tax advantages and by employer contributions, if any.
The superficial view is that 401k plans overtook pensions because companies wouldn't have to contribute much (or anything at all), shifting retirement costs entirely onto workers. But this is ahistorical since initial 401k plans offered extremely generous employer contribution rates, some approaching 15% matching. Of course, the reasoning then was that the tax savings for the company would exceed that, and so it was a way to increase compensation for top talent. In the 80s and 90s was when the 401k was only just taking hold as a fringe benefit, so you had to have a fairly cushy job to have access to a 401k plan.
Another popular viewpoint is that workers prefer 401k plans because it's more easily inspectable than a massive pension fund, and history has shown how pension funds can be mismanaged into non-existence. This is somewhat true, if US States' teacher pension funds are any indication, although Ontario Teacher's Pension Plan would be the counterpoint. Also, the 401k plan participants at Enron would have something to complain about, as most of the workers funds were invested in the company itself, delivering a double whammy: no job, and no retirement fund.
So to answer the question directly, it is my opinion that the explosion of 401k plans and participants in such plans -- to the point that some US states are enacting automatic 401k plans for workers whose employers don't offer one -- is due to 1) momentum, since more and more employers keep offering them, 2) but more importantly, because brokers and exchanges love managing them.
This is the crux: only employers can legally operate a 401k plan for their employees to participate in. But unless the employer is already a stock trading platform, they are usually ill-equiped to set up an integrated platform that allows workers to choose from a menu of investments which meet the guidelines from the US DOL, plus all other manner of regulatory requirements. Instead, even the largest employers will partner with a financial services company who has expertise on offering a 401k plan, such as Vanguard, Fidelity, Merrill Edge, etc.
Naturally, they'll take a cut on every trade or somehow get compensated, but because of the volume of 401k investments -- most people auto-invest every paycheck -- even small percentages add up quickly. And so, just like the explosion of retail investment where ordinary people could try their hand at day-trading, it's no surprise that brokerages would want to extend their hand to the high volume business of operating 401k plans.
Whereas, how would they make money off a pension fund? Pension funds are multi-billion dollar funds, so they can afford their own brokers to directly buy a whole company in one-shot, with no repeat business.