Strongflex Bushings for BMW E9X – Complete Guide to Colors, Hardness & Fitment
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Why Upgrade to Strongflex Polyurethane Bushings?
The factory rubber bushings on your BMW E9X were engineered for comfort and compliance — not for precision handling. Over time, they degrade, crack, and introduce unwanted flex into the suspension geometry. The result: vague steering, inconsistent cornering behaviour, and accelerated tyre wear.
Strongflex polyurethane bushings are a direct replacement that eliminates this flex without the harshness typically associated with solid mounts. They're a proven upgrade for street, track, and motorsport applications — and they're made in Europe to exacting tolerances.
What Makes Strongflex Different?
Strongflex is a Slovenian manufacturer with decades of experience producing polyurethane suspension components. Their bushings are:
- Manufactured from high-grade polyurethane — not rubber
- Self-lubricating with integrated grease nipples on most kits
- Available in multiple hardness levels for different use cases
- Colour-coded for easy identification
- Designed as direct OEM replacements — no modifications required
Understanding Strongflex Color Coding & Hardness Levels
One of the most important things to understand before purchasing Strongflex bushings is their colour-coded hardness system. Each colour represents a different durometer (hardness rating), which directly affects ride quality, NVH (noise, vibration, harshness), and handling precision.
| Colour | Hardness | Best For |
|---|---|---|
| Yellow | Soft (street) | Daily drivers, comfort-oriented builds |
| Red | Medium (sport) | Sport street use, occasional track days |
| Black | Hard (race) | Track cars, motorsport, maximum precision |
For most E9X owners using their car on the road, the yellow (soft) or red (sport) variants offer the best balance between improved handling and acceptable NVH levels. Full black kits are best reserved for dedicated track builds where ride comfort is not a priority.
For a full visual breakdown of the colour system and hardness guide, see our Strongflex Colors & Hardness Guide.
Strongflex Bushing Categories for the BMW E9X
We stock Strongflex bushings across all major suspension points on the E9X platform. Here's an overview of what's available and what each category covers:
Front Suspension Bushings
The front suspension on the E9X uses a double-wishbone setup with multiple rubber mounts that are prone to wear. Replacing these with Strongflex polyurethane units sharpens steering response and reduces front-end dive under braking.
→ Shop Front Suspension Bushings
Rear Suspension Bushings
The rear multi-link suspension of the E9X is particularly sensitive to bushing condition. Worn rear bushings cause toe and camber changes under load, leading to unpredictable handling at the limit. Strongflex rear bushings restore geometry stability and improve traction.
→ Shop Rear Suspension Bushings
Anti Roll Bar Bushings
Anti roll bar (ARB) bushings are often overlooked but play a critical role in body roll control. Factory rubber ARB bushings compress and allow the bar to shift under load. Strongflex ARB bushings eliminate this movement, giving you more consistent and predictable roll stiffness.
Differential Bushings
The rear differential is mounted via rubber bushings that absorb torque loads. Under hard acceleration, worn diff bushings allow the differential to move, causing wheel hop and imprecise power delivery. Strongflex differential bushings lock the diff in place for sharper, more consistent acceleration.
Full Bushing Kits
If you're doing a full suspension refresh or building a track car, a complete Strongflex kit covers all suspension points in one go. This is the most cost-effective approach and ensures consistent hardness across the entire chassis.
→ Shop All Strongflex Bushings
BMW E9X Compatibility
Strongflex bushings are available for the full E9X range:
- E90 – 3 Series Sedan (2005–2011)
- E91 – 3 Series Touring (2005–2012)
- E92 – 3 Series Coupé (2006–2013)
- E93 – 3 Series Convertible (2007–2013)
Fitment covers all engine variants including N52, N54, N55, and S65 (M3). Always verify your specific chassis code and production date when ordering.
Installation Tips
Strongflex bushings are designed as direct OEM replacements, but a few tips will ensure a clean installation:
- Press out the old bushings using a hydraulic press or bushing removal tool — avoid hammering where possible to protect the surrounding metalwork.
- Clean the housing thoroughly before pressing in the new bushing. Any debris or corrosion will affect fitment and longevity.
- Apply the supplied grease to the bushing bore and outer shell before installation. Strongflex kits include grease for this purpose.
- Torque to spec with the suspension at ride height — tighten all suspension bolts with the car at normal ride height (not hanging), to avoid pre-loading the bushings.
- Re-grease periodically via the integrated grease nipples (where applicable) to maintain performance and prevent squeaking.
If you're not comfortable with suspension work, have the installation carried out by a qualified workshop familiar with BMW suspension systems.
Frequently Asked Questions
Will Strongflex bushings make my E9X uncomfortable to drive daily?
In yellow (soft) hardness, the difference in NVH compared to new OEM rubber is minimal. Most drivers report a noticeable improvement in handling feel with only a marginal increase in road noise. Red (sport) bushings are still very liveable on the street for most drivers.
Do I need a wheel alignment after fitting Strongflex bushings?
Yes — always perform a four-wheel alignment after replacing suspension bushings. Even if the geometry hasn't changed, it's good practice and ensures your tyres wear evenly.
How long do Strongflex bushings last?
Polyurethane bushings significantly outlast rubber in most applications. With proper lubrication, Strongflex bushings can last the lifetime of the vehicle.
Can I mix hardness levels across the car?
Yes, this is common practice. Many builders use softer bushings at the front for steering feel and harder bushings at the rear for stability. Consult with a suspension specialist if you're unsure.
Ready to Upgrade Your E9X Suspension?
Strongflex polyurethane bushings are one of the highest-impact, lowest-cost upgrades you can make to your BMW E9X. Whether you're chasing sharper street manners or building a serious track weapon, there's a Strongflex kit for your application.