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Description

AST Bolt-in Roll Cage BMW F21 V4

The AST Bolt-in Roll Cage BMW F21 V4 is a full roll cage for the BMW 1 Series F21 with three-door hatchback bodywork. In addition to the continuous structure and the door bars, this Bolt-in F21 V4 also has an extra diagonal brace and a harness bar, giving your harness system a fixed anchor point.

The cage is designed and built by AST Roll Cages in Spain, for drivers who want a fully equipped cage that is bolted into the car.

Key benefits

• Harness bar: a fixed anchor point for your harness, part of the V4 level.
• Extra diagonal brace that further increases the torsional rigidity of the whole structure.
• Door bars for side protection in the three-door bodyshell.
• Six bolting points on six 3 mm steel foot plates welded to the bodyshell.
• Supplied in sections: the welded structure is split at connecting sleeves, making it easy to get through the door opening.
• E355 steel: main hoop 45 mm, rest of the structure 40 mm.
• Exact fit: laser scan of the F21 bodyshell and a 3D design based on it.

Suitable for

BMW 1 Series F21, three-door hatchback

• BMW 1 Series F21 three-door hatchback, built 2012 to 2019
• Type: full bolt-in roll cage, version V4
• Not interchangeable with the five-door F20: AST designs a dedicated cage for each body style
• Drifting, track use and rallying

Technical specifications

• Manufacturer: AST Roll Cages
• Manufacturer part number: CMBN06414
• Sunroof: for roofs without a sunroof
• Headlining: for roofs without headlining
• Rear anchorage: in the rear suspension area
• Rear structure layout: V design
• Type: full roll cage, bolt-in on welded foot plates
• Main hoop: E355 steel, 45 mm diameter
• Secondary structure: E355 steel, 40 mm diameter
• Foot plates: 3 mm steel, custom-designed for each car
• Mounting: 6 bolting points on 6 foot plates welded to the bodyshell
• Weight: 210 kg (manufacturer’s figure)
• Finish: welded and unpainted, in sections via connecting sleeves
• Included: welded structure, connecting sleeves, reinforcement plates, bolts, washers and nuts, documentation, fitting instructions and sticker set

Fitting and delivery

The cage is built to order; the standard delivery time is 15 to 35 working days. Good to know: bolt-in here means that the cage is bolted onto the foot plates, but those six foot plates are welded to the bodyshell. So expect welding work by a skilled fitter.

Fully equipped roll cage with harness bar, bolted onto welded foot plates in the three-door F21.

Why choose this Bolt-in F21 V4?

For many drivers, the harness bar is the turning point: without a fixed anchor point for your harness, a bucket seat never works the way it is meant to. The V4 provides that, plus an extra diagonal that makes the whole structure more rigid. AST digitises the bodyshell with laser scanners and designs the cage in 3D, so you do not have to modify anything in a three-door F21.

Frequently asked questions

Does this cage involve welding?

Yes. On the Bolt-in F21 V4, the six foot plates are welded to the bodyshell; the cage itself is then bolted in place. A cage with no welding at all does not exist in this range.

Does this cage fit the five-door F20?

No. This version is designed around the three-door F21 bodyshell. AST makes a separate cage for the five-door F20, and the two are not interchangeable.

Can I use this cage in competition?

The cage is intended for track and competition use. Which technical requirements apply depends on your governing body or organiser; check those regulations before you enter.

What is the delivery time?

The standard delivery time for this roll cage is 15 to 35 working days.

Delivery outside the European Union: different shipping costs may apply. Don’t worry: we will email you as soon as possible after your order and agree the shipping with you. You are not committed to anything without your consent.