ST X Height Adjustable Coilovers for BMW 1 Series M135i/M140i (F20/F21) | 2WD & xDrive | No EDC | 30-55mm Lowering | KW Engineered Suspension Kit

Height-Adjustable Sport Suspension for BMW 1 Series M135i and M140i F20 F21

Give your BMW 1 Series the stance, control and confidence it deserves. This ride-height adjustable shock and spring package is engineered for the M135i and M140i on the F20 and F21 platform, transforming road feel with tighter body control, accurate steering response and a purposeful drop that works on British roads.

What this upgrade delivers

• Sharper turn in and reduced roll for quicker direction changes
• Consistent damping for fast B-road drives and motorway comfort
• Adjustable ride height to dial in your preferred look and wheel fitment
• Confident traction on RWD and AWD models in mixed weather
• German-developed damping for reliable, repeatable performance

Ride height range

• Front drop: 30 to 55 mm
• Rear drop: 30 to 55 mm

Construction highlights

• Twin-tube dampers with precise valving for balanced control
• Galvanised strut bodies with extra corrosion protection for UK winters
• Chrome plated piston rods for durability and smooth operation
• Monoblock guide and advanced seal package to keep dirt and water out
• Polyamide height adjuster for easy, accurate changes
• Vehicle-specific springs, bump stops and dust boots included

Compatibility and important notes

• Chassis: BMW 1 Series F20 and F21, M135i and M140i
• Drivetrain: Suitable for rear wheel drive and xDrive all wheel drive
• Damping: For cars without factory electronic dampers non adaptive
• Axle loads vary by spec. Check your VIN plate and choose the correct rating
• Actual lowering depends on vehicle equipment and approved axle loads
• A professional four wheel alignment is strongly recommended after installation

Real world results

We have installed this kit on multiple M135i and M140i builds and the feedback has been superb. Customers report cleaner mid corner balance, improved confidence in poor conditions and a perfect wheel gap for daily use without compromising comfort.

Fitting and setup

Want it fitted and aligned correctly first time? Book professional installation with MJ Modifications in Warwickshire. We can supply fitting, geometry and corner setup tailored to your use. Request a quote at info@mjmodifications.co.uk.

What is included

• Height adjustable front and rear damper units
• Performance springs for both axles
• Adjustable spring perches, bump stops and dust covers
• Vehicle-specific mounting hardware where required

Search-friendly terms to help you find this upgrade: BMW F20 F21 suspension upgrade, M135i suspension kit, M140i suspension kit, adjustable shocks and springs, coil over suspension for BMW 1 Series, lowering solution for RWD and AWD, non adaptive suspension compatible, road and track suspension, performance chassis kit, ride height adjustable shocks, sport suspension UK, German engineered suspension, BMW 1 Series drop kit, wheel fitment friendly stance, cornering upgrade for M135i M140i.