Insole comparison
Springsoles vs VKTRY carbon fiber insoles
Two products, two completely different ideas about how a shoe should give energy back. One is a moulded carbon fiber plate that replaces your insole. The other is a patented rubber layer, 3/32 of an inch thick, that goes underneath the insole you already have. Here is the honest breakdown, with every claim about another brand sourced to that brand's own site.
The short answer
Choose Springsoles if
- You compete in cleats or court shoes where there is no room for a plate.
- You want your factory fit and arch left exactly as it is.
- You want one pair that moves between shoes, sports and work boots.
- You want documented patents and named lab work behind the claim.
- You want to spend under thirty dollars to find out.
Choose a carbon plate if
- You want a structural, orthotic-class replacement insole.
- You have the shoe volume to give up and are happy refitting.
- You want stiffness matched to your body weight by the maker.
- Premium pricing per pair is not a concern.
These are different tools. A plate changes the structure under your foot. Springsoles changes the material your foot pushes into, without changing the shoe.
Side by side
| Factor | Springbak® Springsoles | Carbon fiber plate insoles (VKTRY) |
|---|---|---|
| What it is | A thin resilient energy-return layer made from a patented 1,4-polybutadiene rubber composition. It is a material, not a structure. | A moulded carbon fiber baseplate built into a full replacement insole. VKTRY describes its product as carbon fiber sports performance insoles with a patented carbon fiber baseplate. |
| Where it sits | Underneath the insole already in your shoe or cleat. Your factory fit, arch shape and volume stay exactly as they were. | In place of the insole already in your shoe. The stock insole comes out and the plate insole goes in. |
| Thickness and fit | 3/32 inch. No break-in period, no volume change, and the same pair moves between cleats, court shoes and work boots. | A structural plate is substantially thicker and stiffer than a stock insole, so fit and shoe volume change with it. |
| Sizing model | Trim-to-fit by shoe size. One version, no stiffness tiers to pick between. | VKTRY selects a baseplate from five stiffness levels using body weight and age, and sells separate product tiers. |
| Cost per pair | $29.95, made in the USA. Check current pricing on our shop page. | Priced as a premium orthotic-class product. Check vktry.com for current pricing rather than trusting any third-party figure, including ours. |
We publish no performance numbers for another company's product and no price we have not verified today. Where a figure matters to your decision, check it at the source below.
What is actually documented on our side
Four issued United States patents, filed by inventor William R. Crow and granted between 1996 and 2003, cover the energy-return composition and the components formed from it: 5,554,694 · 5,695,850 · 6,120,880 · 6,589,630 B1. The patent record is public and every filing is linked on our patents page.
In force-plate testing at the Weber State University human performance lab, it took more than twice the force to displace a person standing on Springsoles. Howard Gray, PhD, then Director of the Department of Gerontology at Brigham Young University, sponsored that work and concluded there is a significant strength increase for individuals using Springsoles. At the University of Southern California, Dr. Robert Wiswell found athletes in Springsoles took fewer strides over the same distance than in placebo inserts, consistent with increased stride length.
That is the whole claim, stated plainly: the proof page carries the study detail and the technology page explains what the patents protect and what stays a trade secret.
On the record
On the record
Researchers, coaches and athletes on the Springbak® approach.
“Our department sponsored a strength and stability study at the Weber State University human performance lab. After reviewing the force plate data, showing it took more than twice the force to push off the subjects off the force plate when standing on Springsoles, we have to conclude there is significant strength increase to individuals utilizing Springsoles.”
Questions athletes ask before switching
Is Springsoles a carbon fiber insole?
No. Springsoles is a patented rubber energy-return material, not a carbon fiber plate. A carbon plate works by being stiff and springing back structurally. Springsoles works chemically: a 1,4-polybutadiene composition that returns energy rather than only absorbing it, in a layer 3/32 of an inch thick.
Do I take my existing insole out?
No, and this is the clearest practical difference. Springsoles goes underneath the insole already in your shoe, so your factory fit is untouched. A plate insole replaces your stock insole, which changes shoe volume and arch shape.
Which one is better for cleats?
Cleats have very little internal volume, which is why Springsoles is 3/32 of an inch and sits under your existing insole. If you compete in football, soccer, baseball or track spikes, thickness is the deciding factor. Our sport pages cover the fit for each footwear type.
What evidence does Springbak have?
Four issued U.S. patents (5,554,694, 5,695,850, 6,120,880 and 6,589,630 B1) and named laboratory work. In force-plate testing at the Weber State University human performance lab, it took more than twice the force to displace a person standing on Springsoles. At USC, Dr. Robert Wiswell found athletes took fewer strides over the same distance than in placebo inserts.
Why is Springsoles so much less expensive?
There is no moulded structure, no stiffness-tier inventory and no custom fitting step. It is a material layer manufactured in the USA and sold as one version you trim to your shoe size.
Can I use both at once?
We do not recommend stacking Springsoles under a structural plate insole. The plate already fills the volume a shoe has to give, and a rigid plate is not the surface Springsoles is designed to work against. Use Springsoles under a normal factory or foam insole.
References & sources
Try the cheaper experiment first
One pair is $29.95 and goes under the insole you already own, so nothing about your shoes has to change to find out whether it works for you.
Still deciding? Ask us directly.
Tell us your sport and the shoes you compete in and we will tell you honestly whether Springsoles fits them.