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Big Brake Kit

XYZ Racing Hollow Rear Brake Kit — Smart SMART (FOR FOUR) (2004-2006)

SKU: XYZ-BRK-BKR-SM-001-REAR

  • IncludesRear axle pair (2 discs + 2 calipers)
  • PositionRear
  • Disc Ø380–421 mm
  • Caliper pots8-pot
  • Lead time10–15 working days

Fits Smart SMART (FOR FOUR) (2004-2006)

Brake pad compound

Street: quiet, low-dust, strong cold bite for road driving. Sport: higher temperature range and more bite for fast road and occasional track. Racing: maximum fade resistance for sustained track use (noisier and dustier cold). Match the pad to how hard you actually brake.

Disc size

Caliper grade

Hollow is the standard caliper: a lighter hollow-body forged caliper with a dust cover and a 5-year warranty. Hollow Racing drops the dust cover for sustained high-temperature use (rated to 1000°C, 2-year warranty) — the track-grade choice.

Caliper colour

Painted colours are included. Polished-forged finishes are mirror-polished forged calipers (Titanium, Gold, Silver); candy colours are a deep, mirror-reflection paint. Both are premium upgrades — fuller detail further down the page.

Painted — includedTell us the exact Pantone (PMS) code you want the calipers painted.Polished forgedCandy
Disc style

Drilled discs (cross-drilled holes) vent gas and water and look aggressive; slotted discs (surface grooves) wipe the pad face clean and resist fade under sustained hard use. Same price — choose on looks or how you drive.

Centre bell

The centre bell is the CNC-machined aluminium hat that joins the disc to the hub. Standard anodized is included; a two-tone bell adds an anodized accent ring in your choice of colour; titanium is the lightest, forged option.

Carbon-ceramic rotor

Carbon-ceramic rotors are a special-order track upgrade: far lighter than steel, fade-resistant at extreme temperatures and extremely long-lived. The price follows the disc size you choose above. The standard two-piece steel rotor is included.

Configured price£3,000.00Inc. VAT

Lead time: 10–15 working days from payment


£3,000.00

Made to order. Full payment is taken at checkout. Production begins once payment is confirmed.

Pay by card, Apple Pay, Google Pay — or Klarna on eligible orders.

Caliper render for this kit:

XYZ Racing Hollow Rear Brake Kit — Smart SMART (FOR FOUR) (2004-2006) — 380 mm
380 mm

The first-generation Smart ForFour (W454) sends almost all of its stopping effort to the front axle, which leaves the rear doing comparatively little on a car this light and short in the wheelbase. That front bias is fine around town, but lean on the brakes hard down a B-road or on a track day and the back end stays passive while the nose works overtime. The XYZ Racing rear brake kit for the 2004-2006 Smart ForFour rebalances that picture, giving the rear axle a matched pair of bigger, more thermally capable two-piece floating discs to share the load.

This is a rear-only upgrade aimed at owners who want firmer, more progressive pedal response and a brake balance that suits faster road driving and occasional circuit use rather than just commuting. The disc design keeps rotating mass in check on a chassis where every kilo at the wheel matters.

What this brake kit does for your 2004-2006 Smart SMART (FOR FOUR)

On the road you feel the difference as a firmer, more consistent pedal under repeated braking, because the larger rear discs resist the fade that catches out the small factory hardware on a warm day. Pad compound is your lever for character: the Street option stays quiet and low-dust for daily use, Sport adds bite and heat range for fast road, while the Racing compound bites harder and copes with the heat of back-to-back stops on track. Better rear contribution also settles the ForFour under trail-braking into tight corners, taking some of the workload off the overstretched front axle. Caliper finishes come in Red, Yellow, Gold, Black or Anodized Black at no extra cost, with a custom Pantone option, so the look behind the wheel matches the rest of the build.

About the rear big brake kit

The kit pairs upsized two-piece floating rear discs with fixed calipers, sized to fit the ForFour’s modest rear-axle packaging. The disc is the headline: its hollow-vane internal structure reduces unsprung and rotating mass, which helps the suspension respond more cleanly and keeps disc temperatures more manageable through hard use, while the floating mount lets the friction ring expand under heat without warping its alloy bell. Disc faces come drilled or slotted at the same price, chosen when you order. Three pad compounds are offered, Street, Sport and Racing, so the kit can be set up for a quiet daily car or a sharper fast-road and track tool. The caliper bodies are hollow-cast as standard, with an optional Hollow Racing upgrade for track-focused cars that removes the dust cover, is rated to 1000C and carries a two-year warranty. Caliper colour is specified when you order. It is a focused rear setup rather than a full-car overhaul, designed to correct the W454’s front-heavy braking character.

Fitment for the Smart SMART (FOR FOUR) (2004-2006)

This kit fits the first-generation Smart ForFour (W454 platform) across the 2004 to 2006 model years and mounts at the rear axle. Confirm your exact production year against the options above before ordering to be sure of the correct rear-axle fitment.

What buyers also search for

  • Smart ForFour rear big brake kit upgrade for the 2004-2006 W454
  • Smart ForFour rear brake disc and caliper kit for fast-road and track use
  • Smart ForFour Racing pad compound options for better rear braking balance
  • Coloured brake caliper choices for the Smart ForFour rear axle
  • Light-car rear brake upgrade that improves front-to-rear brake balance

Choose your pad compound and caliper colour, then build your rear brake setup from the options above.

What’s in the kit

Rear axle kit — supplied as a complete bolt-on assembly.

  • 2×Two-piece floating discs — 380–421 mm: you pick the exact diameter with the "Disc size" option
  • 2×Lightweight aluminium centre bells
  • 2×Forged aluminium calipers — 8-pot
  • 2×High-stiffness mounting brackets
  • 2×Braided stainless steel brake lines
  • 4×High-performance brake pads (1 set)
  • 1×Fitting hardware & tools pack

Parking brake: OE handbrake not retained — a hydraulic handbrake is required.

Choosing your spec

Every kit is built to order around the choices you make above. Here is what each option actually changes, so you can spec yours with confidence.

Brake pads — Street, Sport or Racing

Every kit ships with a full set of high-performance pads; the compound is your call.

Street is the right default for fast-road driving — a strong, progressive cold bite with low noise, low dust and long disc life. Sport raises the working temperature and adds bite and fade resistance for hard road use and the occasional track day, while still behaving on a cold morning. Racing is a track compound built for sustained abuse: huge fade resistance and bite once heat is in it, at the cost of more noise and dust when cold. Match the pad to how hard you actually use the brakes — there is no benefit to a race pad that never gets up to temperature.

Caliper grade — Hollow vs Hollow Racing

Hollow is the standard caliper on every kit: a hollow-body forged caliper, lighter than a solid one, fitted with a dust cover and backed by a 5-year oil-leak warranty. For most fast-road and spirited track use it is all the caliper you need.

Hollow Racing is the track-grade upgrade. It runs the same hollow body but without a dust cover (so there is nothing to melt at sustained high temperature), uses a twin-metal piston that isolates heat travelling from the disc to the oil seal, and is rated to 1000°C. Available 330–356mm (rear). Warranty is 2 years on oil leaks and 10 years on appearance. Built for professional racing and repeated track days.

Hollow Racing caliper

Caliper colour & finish

Painted colours (Red, Yellow, Gold, Black, Anodized Black) are included at no cost. Want an exact match to your car? Custom Color (+£150) paints the calipers to any Pantone code you supply (15–20 day lead time).

Polished Forged finishes are the flagship: a forged caliper given a mirror-polished surface treatment that shifts colour with the viewing angle. Beyond the looks, the polished surface dissipates heat better, resists rust and stands up to the weather. Choose Titanium (neochrome, +£350), Polished Gold (+£300) or Polished Silver (+£250). They look their best paired with a titanium centre bell. Care: clean only with a dilute neutral cleaner or water.

Candy colours (+£200) use a deep candy-paint and polishing process for a mirror-reflection, boutique finish — pick Teal, Blue, Red or Orange (shown below right).

Polished forged caliper finishes
Candy caliper colours

Centre bells

The centre bell is the CNC-machined aluminium hat that joins the disc to the hub. The standard anodized centre bell is included. The Two-tone bell (+£200) adds an anodized accent ring — choose Red, Yellow, Orange, Purple or Silver right here at checkout. The Titanium centre bell (+£500) is a forged titanium bell (bolts not included) that finishes off the polished-forged look.

Two-tone anodized centre bells
Same car

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