How to avoid painful bra straps that hurt, chaff, cut shoulders: -Engineering has the answer.

Painful bra straps that chaff, cut, mince are the most commonly reported bra annoyances.

Everyone has a recipe to tame evil straps but only very few know the fundamental causes of so many lamentations.

Bra shoulder straps carry (heavy) boobs and uplift them against the pull of gravity.

As such they are structural elements that transfer forces to the shoulders and can be modeled as belts over pulleys.

And that's where several fascinating phenomena occur.

Pressure being the most intuitive of them. That's how we cut cheese with a wire.

A narrow belt, in this case a thin wire, is capable to generate tremendous pressures with little effort. Right.

Thin wires can generate destructive pressures.
That's how we cut cheese.

Pressure is defined as applied force divided by contact surface: P=F/S where P is the pressure, F the applied force and S the contact surface.

Simple and self explanatory. The smaller the surface, the greater the pressure.

Which is why those trendy close to nothing itsy-bitsy straps can inflict pain and in extreme cases, damage, cut the skin and what's under. Haven't we all a story of a shoulder mincing bra to tell? Sadly, yes.

Merchandised as modern comfort enhancements, elastic stretch straps hide a couple of viciously insidious comfort killer painful and often poorly understood effects.

Shoulder abrasion by stretch bra strap.

Being stretchy they will extend under load and retract back when the tension decreases.

Precisely what happens at every movement and promotes bouncing.

Repetitive sliding of the extending and retracting stretch straps causes friction and abrasion of the skin around which they act. Alike what wears pulleys when machinery is subject to vibrations.

Physics reserves quite a few more surprises to loaded stretchy straps.

Elastic deformation of flat straps actually happens in all directions and prompts the strap material to "creep" and extend more on the edges than along the center-line.

Which results in the formation of a "V" shaped profile as (exaggeratedly) rendered below.

Bra straps material creeping to "V" shape and
ensuing cutting sensation.

Leading to a decreased carrying capacity as forces concentrate on the sharp edge of the "V".

Are stretchy bra straps as comfy and tender as the public perception of elastic fabrics?

No. Material engineering says big time no. Narrow loose stretch straps are the cheapest option almost universally adopted to create a false initial comfort feeling before physics ineluctably takes over in the long run.

That's when strap adjustment enters the realm of voodoo. Just check how many posts and pages on interweb are dedicated to recipes, magic math, alterations and finally surrender to the reality of poorly made bras.

Is such the unavoidable fatality we all face? No. Big time no.

The solution exists and is nothing new under the sun: -Wider rigid straps. As simple as it gets.

Long ago most bras had such straps. Then modern marketing took over and stretchy one-size-fits-most cheaper to scale in different sizes bras invaded the the boob-scape. What a shame.

So what is the secret of wide rigid straps?

First, properly designed support cups need comparatively little strap stretch as they transfer breathing movements to the wings and back.

Then, rigid straps reduce bouncing and therefore the need to compensate by stretching.

Back elasticity compensates rigid straps movement.

Last but not least, rigid straps rely on the back for elasticity and shoulder movement compensation. It's all a connected force distribution structure.

The back of a bra is where the band covers the body with little inwards pressure as the dominant effort is longitudinal and not perpendicular to the body. The perfect location for elastic stretch oscillations without chaffing and skin abrasion.

So what gives ? Simple.

Correctly adjusted rigid shoulder straps on a properly engineered bra will provide uttermost support with unmatched comfort in all situations.

As simple as it gets. Alike engineering, if a detail causes trouble, we can spend precious time fixing it or directly eliminate it right from the start.

Confirmed by my first-hand experience after I adopted Elila bras with wide rigid straps for my fleet. Bye bye shoulder and strap issues, all stays put, safe, cozy and comfy.

Wide rigid straps offer better
lateral stability and don't fall.

Last but not least, wide rigid straps veer less off-course under lateral loads and when the correct tension is set will not slide and fall.

Consecutively I wrote this post to share the joy.

I love you, I love you all !