The Bushings and mounts category covers suspension and driveline bushings, engine mounts and various polyurethane inserts that improve stability and durability. Compared with conventional rubber, polyurethane bushings from brands such as Strongflex and Epman offer higher stiffness, better resistance to oil and heat and more precise handling for both road and motorsport use. This section will expand to include control arm, subframe, anti-roll bar and engine mount solutions for a wide range of makes and models.
Net price: 29 €
Role and Benefits of Bushings and Mounts
Bushings and mounts are the flexible joints that connect suspension arms, subframes, stabiliser bars and the engine–gearbox assembly to the chassis while damping noise and vibration. Factory rubber bushings provide good comfort but soften and crack over time, allowing unwanted movement that alters geometry under load. Upgrading to high-quality polyurethane bushings greatly improves durability and reduces compliance, so wheel alignment stays closer to its intended values under braking and cornering, which translates into sharper steering and more stable handling.
Strongflex polyurethane bushings are offered in different hardness levels, typically around 80 ShA (red) for fast-road and 90 ShA (yellow) for race applications. The harder compound limits how far the bushing can deflect, keeping control arms and subframes located more accurately relative to the body. This improves turn-in, reduces toe and camber change under load and gives a more connected feel through the steering wheel, at the cost of some additional noise and vibration compared with soft OEM rubber.
Technical Basics
Conventional rubber bushings are designed to work primarily in shear and torsion, letting arms and brackets move a few degrees while isolating harshness from potholes and road joints. As they age, the rubber hardens, cracks and can slip within its shell, which allows geometry to wander and can cause clunks, steering vagueness and uneven tyre wear. In extreme cases, heavily worn bushings can let components shift enough to affect braking stability and high-speed confidence.
Polyurethane bushings use a denser elastomer with significantly higher stiffness than typical rubber, and Strongflex units are explicitly described as being around 20% stiffer than comparable OEM items. Red 80 ShA parts are aimed at sporty road use, while yellow 90 ShA versions target circuit and competition where geometry control is more important than comfort. Polyurethane resists oil, salt and temperature swings far better than rubber, making it ideal for exposed locations such as subframe mounts, diff mounts and engine or gearbox supports.
The range includes not only suspension arm and anti-roll bar bushings but also engine mounts and gearbox mounts. Stiffer engine mounts reduce how much the powertrain rocks under hard acceleration or aggressive gear changes, improving throttle response and consistency in driveline alignment. The trade-off is that more engine vibration and exhaust resonance can make its way into the cabin, especially with track-oriented hardness. Design-wise, bushings can be steel-shelled with bonded inserts, two-piece polyurethane designs with a separate sleeve or full polyurethane units with metal sleeves pressed through.
Many Strongflex kits are sold as complete sets for a given car – for example, full front and rear suspension, subframe and diff bushing packages – while others focus on high-impact locations such as front lower arm rear bushings or rear subframe mounts. These targeted upgrades can already deliver a noticeable improvement in braking stability and mid-corner control without committing to a full-car re-bush. For dedicated drift and time-attack builds, however, it is common to replace as many factory rubber bushings as possible with polyurethane or solid alternatives to minimise any elastic movement.
Selection Criteria
When choosing bushings, start by considering how the car is used: daily road driving, mixed street/track or pure competition. For daily use, softer polyurethane or high-quality rubber replacements are often best—such as red 80 ShA Strongflex parts—which give a tighter feel without making the car harsh. For regular track days or competition, yellow 90 ShA race bushings provide the greatest geometry control but will transmit more NVH into the cabin.
Next, identify the exact make, model, generation and drivetrain layout. The Strongflex catalogue is organised by marque and chassis code, with dedicated kits for each platform; even different generations of the same model can use very different bushing layouts. Always choose the parts listed specifically for your car rather than guessing from similar-looking items, as outer/inner diameters, lengths and mounting styles can all differ. If you are building a custom suspension setup, universal bushings can be used, but only with careful measurement and fabrication.
Decide whether to re-bush the entire car or focus on key areas. A full bushing kit transforms the overall character—steering becomes much more direct and the car stays composed in combined braking and cornering—but also increases overall stiffness and NVH. Partial upgrades, like replacing front control arm and rear subframe bushings, can deliver much of the performance benefit with a smaller comfort penalty and lower cost. For drift or time-attack applications, most builders aim to eliminate as much compliant movement as possible throughout the suspension and driveline.
Installation & Maintenance
Replacing bushings and mounts requires appropriate tools and experience, so complex suspension work is best left to a professional workshop. Old bushings are usually pressed into arms or subframes and may need a hydraulic press, dedicated pullers or a combination of heat and cutting to remove. When installing new polyurethane components, pay close attention to orientation marks and shoulders, and only use the lubricant supplied or recommended by the manufacturer—some bushings require specific grease, and mineral oils are often expressly forbidden.
After installation, torque all bolts to the manufacturer’s specified values with the suspension at normal ride height, not hanging at full droop. Tightening with the suspension fully drooped can pre-load the bushings, shortening their life and distorting alignment once the car is back on the ground. An alignment check is strongly recommended after major bushing work, and engine or gearbox mount replacement should be done with the powertrain properly supported so that mounts are not stressed or twisted during tightening.
In terms of maintenance, quality polyurethane bushings are long-lived, but periodic inspection is still important. Look for cracks, surface degradation, signs of metal-to-metal contact or bolts that have started to loosen. Unusual noises, new clunks or sudden changes in steering feel can indicate bushing or mount issues. On track-driven cars it is wise to inspect suspension and subframe bushings at least once per season, paying particular attention to rear subframe and diff mounts, which see very high loads under hard launches and kerb strikes.
FAQ
How are polyurethane bushings better than stock rubber?
Polyurethane bushings are stiffer and more durable than typical OEM rubber, resisting softening, cracking and deformation under heat, oil and load. This keeps suspension geometry more stable, improving steering precision and cornering grip, but usually increases noise and vibration slightly.
Are polyurethane bushings suitable for a daily-driven car?
Yes, especially in softer grades such as 80 ShA “fast road” bushings. These offer a noticeable improvement in response without making the car uncomfortably harsh. Full race-spec 90 ShA sets are usually better reserved for track-focused builds where performance outweighs comfort.
Will stiffer bushings make the car much noisier?
Some increase in NVH is expected, particularly if you stiffen engine and subframe mounts as well as control arms. How noticeable it is depends on the car and the combination of parts, but in return you gain significantly more precise response to steering, throttle and brake inputs.
Should I replace all bushings at once?
A full-car re-bush gives the biggest transformation, making the chassis feel tighter and more responsive everywhere. However, if budget is limited, focusing first on high-load locations such as front lower arms and rear subframe mounts can deliver a large proportion of the benefit, with the option to upgrade the remaining bushings later.
How long do polyurethane bushings last?
When installed correctly and lubricated where required, quality polyurethane bushings generally outlast OEM rubber parts, even under spirited driving. On hard-used track cars the rest of the suspension—joints, bearings and dampers—often becomes the limiting factor before the bushings themselves wear out.
