Just came across this website/ product and was pretty intrigued, the website doesn’t do a great job of explaining what the product is of how it works so I asked Gemini which explained below
What are people’s thoughts on this concept and has anyone tried one?
https://oversuspension.eu
Oversuspension is a product that acts as a "gravitational resonator" to control tire rebound, especially on motorcycles. To understand how it works, it's helpful to first understand what tire rebound is and how it relates to a standard suspension system.
The Role of Suspension and Tire Rebound
A vehicle's suspension system is designed to absorb bumps and keep the tires in contact with the road. It has two main components:
Spring: This absorbs the initial impact of a bump, compressing and then releasing energy.
Shock Absorber (or Damper): This controls the speed at which the spring compresses and, most importantly, the speed at which it extends (rebound). The damper prevents the spring from bouncing uncontrollably, which would cause the tire to lose contact with the road.
Tire rebound is a separate, high-frequency bouncing that occurs within the tire itself. When a tire hits a bump, it compresses and then wants to spring back to its original shape. This happens much faster than the main suspension can react, and it can cause the tire to briefly lose contact with the road. This is a critical issue because traction, braking, and steering all depend on the tire being firmly on the ground.
How Oversuspension Works
Oversuspension is designed to specifically address this high-frequency tire rebound, which is often not fully managed by the main suspension. Here's a breakdown of the technology:
Mass Damper Principle: The device is essentially a type of mass damper. A mass damper is a system that uses a tuned mass to absorb unwanted vibrations. The Oversuspension device contains a central core made of a heavy metal (like a tungsten alloy).
Counteracting Vibrations: When the tire experiences a high-frequency rebound, it creates vibrations in the swingarm. The heavy mass inside the Oversuspension device is designed to move in a way that is "counter-phase" to these vibrations. This means it moves in the opposite direction, effectively canceling out the energy of the rebound.
Special Polymer: The device uses an aircraft-grade spring and a special polymer that changes its structure based on the force of compression. This allows the device to respond dynamically to the energy of the impact. The energy from the tire's rebound is dissipated by the movement of the mass against this polymer.
Keeping the Tire on the Ground: By canceling out these high-frequency vibrations, Oversuspension keeps the tire "glued" to the ground. This provides a more constant contact patch, which is the area of the tire that is touching the road.
Benefits of Oversuspension
According to the manufacturer, by controlling tire rebound, Oversuspension provides several benefits:
Improved Traction: A more constant contact patch means better grip, especially during acceleration and cornering.
Better Braking: By keeping the wheel from bouncing, the device improves the effectiveness of braking, particularly with ABS systems.
Increased Stability: By reducing vibrations and maintaining contact with the road, the vehicle feels more stable and predictable.
Reduced Tire Wear: The constant contact and reduced bouncing can help to decrease uneven tire wear.
Reduced Rider Fatigue: Less vibration transferred to the rider can result in less physical strain.
In essence, while a vehicle's primary suspension manages the larger movements of the chassis and wheel, Oversuspension acts as a finely tuned secondary system that specifically targets the quick, uncontrolled bouncing of the tire itself. It's a way of enhancing the overall effectiveness of the suspension by addressing a problem that traditional shock absorbers can't fully solve.
Some of the MotoGP bikes use mass dampers.
They don’t overcome proper suspension setup but I used one years ago and felt it gave the rear of the bike a more stable feel. I bought one last winter for my son‘s KTM 85 and we spent a day testing, taking it on and off, and the back of his bike was definitely more controlled in the braking bumps with it on. Not night and day, but enough to be noticeable. (talk to text edit)
Didn't these get used in both MotoGP and F1 and where banned?
Banned in F1, not MotoGP.
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It's a mass damper. Works well when the bumps you're hitting causes the damper to oscillate 180 degrees out of phase of the bump. Makes everything worse if it happens to go in-phase (or close to it). Either way, you're hauling weight around on the end of your swingarm, which is not a good thing. Whether the pros outweigh the cons depends a lot on the situation, but for a motocross bike, I wouldn't consider it.
In the last year or so, the MTB Downhill 'community' have really glommed on to these as a 'new' thing.
All sorts of dampers, in all sorts of positions, and, a few companies are selling them to the public.
I've noted the disappearance of them, from a few riders / teams bikes that tried them for a while, but, by the same token, others starting to try them.
I / a company I did work for, played with these long ago, for a few types of applications, as have many.
I'm neither for, or against them - if it makes you happy, go for it. But, I settled for good suspension and chassis set up.
Physics says they can be tuned to help for any specific bump frequency and amplitude.
Fine where you have a repeatable situation (F1 or MotoGP, maybe) but in MX or Enduro where the terrain is varied and ever-evolving...about as much use as boobs on a bull.
(If they worked, Honda would be using 'em and Luxon. Would be selling 'em 😁)
Kyle Lewis and moto XXX ran em back in the day I got to try one out and it definitely does make a difference if you're looking for that extra little bit in your setup and you sorted out your suspension pretty well it's worth it. In MotoGP Ducati was the first one to really do the modern version of it for their bikes they called it the salad box or the lunch box
Yeh Ducati put it behind the seat, I would expect it to make the rider feel better, but not smooth-out the unsprung frequency ?
Marquez has been using one on his swingarm this year as well to help with tyre chatter.
Some of the World Cup downhill mountain bike racers at the highest level are playing with those, but I'm in the same camp as @Luxon MX on them for MX.
Tire rebound is a real thing, but I feel like it's not that big of a deal on most MX tracks.
Soft / tilled dirt offers some damping for the tire. Hard pack dry / slick chop is where I'd imagine it is worst for us MX guys.
I do some work in the monster truck industry building shocks, hydraulic steering and gearboxes, etc.
Tire rebound is a serious issue for those guys. The axles weigh so much that they fully compress the tires and rebound hard enough to bounce back up. That bottoms the suspension before the truck chassis has stopped moving downward. I did some tuning with a customer using high frame rate video and it was crazy to watch that axle move as he landed from 30+ feet high.
You recall seeing miller’s chatter on the KTM when he was on it. Was unreal the amount in slo-mo
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