Powerflex Black Series Rear Subframe Front Bush Inserts for BMW 1 Series F20/F21 - Track Polyurethane Bushing Upgrade (Pair) - Replaces OE 33316792509

BMW 1 Series F20 F21 Rear Cradle Front Mount Insert Kit - Powerflex Black Series

Unlock razor sharp handling and rock solid rear axle control on your BMW 1 Series F20 or F21 with this Powerflex Black Series rear cradle front mount insert kit. Engineered from race focused 95 Shore A polyurethane, these uprated poly bushes fill the voids in the factory rubber mounts to curb subframe shift, stabilise the rear end and keep suspension geometry consistent under load. Ideal for track days, sprint, time attack and aggressive fast-road driving where precision matters.

We run these inserts on our own builds at MJ Modifications and customer feedback is consistently positive. Expect crisper turn in, improved traction on corner exit and far greater confidence under hard braking and rapid direction changes. If you are chasing lap time or simply want your 1 Series to feel planted and direct, this is a proven upgrade.

• Application: BMW 1 Series F20 F21 rear cradle, front mounting points
• Construction: Black Series polyurethane, 95A hardness for motorsport-grade response
• Function: Inserts occupy OE bush voids to reduce movement and flex in the sub-frame
• Fitment style: Works with the original equipment rubber bush, no removal of the OE bush required
• Pack size: Pair of inserts
• Diagram reference: 20
• OE reference it suits: 33316792509

What you will feel

• More immediate steering response and sharper rear axle behaviour
• Better stability during cornering, braking and rapid load changes
• Reduced rear sub-frame compliance for repeatable alignment and tyre contact
• Durable, heat and load resistant material designed for circuit use

Searchers also look for: BMW F20 subframe insert kit, F21 rear cradle bush upgrade, 1 Series poly bushings, performance suspension mounts, track day bush set, rear axle mount reinforcement, polyurethane sub-frame inserts, race spec bushes, handling upgrade for BMW 1 Series, drift and circuit suspension parts.

Compatibility

Designed for BMW 1 Series F20 and F21 chassis at the rear sub-frame front location. These inserts install into the cavities of the standard bush to control movement without pressing out the factory mount.

Note: As with any motorsport compound bushing, some increase in NVH compared with stock rubber is to be expected, trading comfort for precision.

Fitting and support

Professional installation recommended. MJ Modifications offer fitting at our Warwickshire workshop. Request a quote at info@mjmodifications.co.uk.

Ready to tighten up the back end of your F20 or F21 and enjoy predictable, repeatable handling on track and spirited road drives? Add this Powerflex Black Series rear cradle front mount insert kit to your basket today.