ST by KW Lowering Springs Kit for BMW 1 Series F20/F21 (2011-2019) - 30mm Front/Rear Drop - Sport Coil Spring Set - Fits M135i, M140i, 125d - Performance Suspension Upgrade, Adaptive Damper Compatible (1K2/1K4 Hatchback)

Give your BMW 1 Series the stance and handling it deserves with this ST by KW performance spring set, delivering an approx. 30 mm front and 30 mm rear ride height reduction. Purpose-built for the F20 and F21 platform, it is a proven upgrade for M135i, M140i and 125d owners who want sharper response, reduced body roll and a cleaner, level look without sacrificing everyday comfort.

Perfect for fast-road driving on UK tarmac, these high-quality drop springs integrate seamlessly with factory shock absorbers, including cars equipped with BMW adaptive dampers. We have fitted these on customer cars and feedback has been consistently positive for stability, steering feel and arch gap reduction.

Why enthusiasts choose this ST spring set

• Approx. 30 mm front and 30 mm rear lowering for a balanced, purposeful stance
• Noticeably tighter turn-in and reduced body movement in corners
• Designed to work with OE dampers, including electronic damping systems
• Factory-grade construction for durability and long service life
• Engineered specifically for the BMW 1 Series F20 and F21 chassis

Construction and quality

• Chrome-silicon steel for strength and consistency
• Multiply tempered for long-term performance
• Epoxy coated for corrosion resistance through British weather
• Vehicle-specific spring rates for a confident, composed ride
• Partial tubing where required for fit and function

Fitment and specifications

• Platform: BMW 1 Series F20, F21
• Models covered: M135i, M140i, 125d and other variants within the specified power range
• Model years: 09/2011 onward
• Power range: 105 to 235 kW
• Maximum front axle load: 960 kg
• Maximum rear axle load: 1110 kg
• Lowering amount: 30 mm front - 30 mm rear
• Compatible with cars fitted with adaptive dampers

Search-friendly terms customers use

BMW 1 Series F20 lowering springs - BMW F21 suspension upgrade - M135i lowering springs UK - M140i suspension springs - 125d drop springs - BMW coil spring set - 30mm lowering kit - performance suspension for BMW hatchback - ride height reduction - stance upgrade - fast road springs - KW engineered ST springs.

Installation and support

Professional fitting available at MJ Modifications in Warwickshire. For a tailored installation quote or advice on suitability for your car’s axle loads, email info@mjmodifications.co.uk.

Note: Always confirm your vehicle’s front and rear axle weights and existing damper type before ordering to ensure compatibility.