ST X Coilover Suspension Kit by KW – BMW 1 Series M135i/M140i F20 F21 (RWD, non-EDC) 2011+ | Height Adjustable Coilovers / Lowering Kit | Adjustable Shocks & Springs

Transform the way your BMW 1 Series drives and looks with this ST X height adjustable suspension system. Built by KW Automotive, it delivers precise ride height control, sharper turn in and a planted, confident feel on British roads. Ideal for fast road use, daily driving and weekend blasts, this suspension upgrade brings real-world performance and reliability without compromising everyday usability.

We have installed this setup for customers and on our own builds, and the feedback has been consistently positive. Expect tighter body control, improved grip over uneven surfaces and a purposeful stance that you can fine tune to your preference.

• Ride height adjustment via robust threaded bodies and a durable polyamide adjuster
• Twin-tube damper technology for balanced control and comfort
• Galvanised struts with additional coating for strong corrosion resistance
• Chrome plated piston rods and low-friction internals for long service life
• Comprehensive sealing package to keep dirt and moisture out
• Supplied as a complete set with adjustable spring perches, performance springs, bump stops and dust protection

Lowering range

• Front: 25 to 50 mm
• Rear: 30 to 55 mm

Permissible axle loads

• Front: 921 to 1090 kg
• Rear: up to 1230 kg

Vehicle compatibility

• BMW 1 Series F20 and F21, M135i and M140i
• Chassis codes: 1K2 and 1K4
• Rear wheel drive models
• For vehicles without electronic damper control
• Model years from 09/2011 onward

Why this upgrade

If you are searching for a BMW 1 Series suspension upgrade that offers adjustable ride height, improved cornering stability and a clean, even drop, this coil over suspension kit is the sweet spot. It is perfect for drivers who want a performance suspension package that enhances handling, reduces body roll and refines steering feedback while allowing you to dial in your stance for road or track days. Keywords people look for include BMW M135i suspension, M140i lowering kit, adjustable shocks and springs, height adjustable struts, performance suspension for F20 F21 and coil over suspension for RWD 1 Series.

Professional fitting

Want it installed correctly the first time? Book fitting with MJ Modifications in Warwickshire. Request a quote: info@mjmodifications.co.uk.