Brompton 7.7kg THM Extralite Ridea NOV SMC JCP 3D Print Ti KCNC Carbon eebrakes

This is a fully custom-built Brompton folding bike that weighs just 7.7kg despite using a steel frame as its foundation. It was conceived as an ultimate urban commuter—light enough to carry through stations and compact enough to fold away, yet refined to ride with genuine smoothness and efficiency. The build blends Brompton's classic compact-fold design with state-of-the-art lightweight components, from 3D-printed titanium parts to premium carbon wheelsets, without sacrificing the understated aesthetic that makes a Brompton feel right in any setting.

The frame started life as a 2018 Brompton and has undergone a complete transformation. It was shot-blasted and finished in gloss clear lacquer with a bespoke colour scheme centred around Turkish green, balanced with black, gold, cream, blue and purple accents across the stem hinge joint and other details. This intentional restraint gives the bike character without the gaucheness of typical raw lacquer builds. The steel frame tubes have been treated inside with Bilt Hamber anti-corrosion wax for protection, and new hinge pins have been installed so the fold mechanism operates without play. Since the respray and assembly, the frame carries only limited mileage, and the stem itself has never been ridden after powder coating.

The drivetrain is entirely single-speed at 52 front ring and 13 rear cog—a ratio that suits flat urban riding and offers effortless acceleration without the complexity of gearing systems. The crankset is a THM Carbone Clavicula SE with lightweight carbon construction, paired with a Lightworks carbon narrow-wide chainring and a THM hybrid ceramic bottom bracket that has been chased and faced. The chain is an SUMC SX10 in oil-slick finish, kept in tension by a Ridea custom chain tensioner fitted with a sealed-bearing 10-tooth pulley. A Brombacher POM titanium pedal with single quick-release completes the pedalling platform.

Braking relies on a Cane Creek eeBrake G4 system with a custom JCP 3D-printed titanium bridge, extended arms for better modulation, and Swiss-stop Black Prince carbon pads. The brake lever is an Extralite Ultralever 3 finished in purple and black. This setup delivers smooth, powerful stopping without the heaviness of traditional rim brakes, and the reverse cable configuration keeps things tidy through the fold.

The wheelset uses SMC Lunate carbon wheels with 3K gloss finishing and ceramic hubs—38mm deep rims that roll noticeably faster than standard Brompton wheels while still maintaining the compact 16-inch size. They're shod with Velotto Fantome mini folding tyres in cream (a limited edition run) and RideNow TPU inner tubes, both chosen for their combination of light weight and practical durability. The front quick-release is a custom SMC slow-release design with a titanium axle.

The seatpost is a full-carbon design from H&H (Matt 12K finish) running to 540mm, topped with an AX Lightness 3K gloss carbon saddle that weighs almost nothing. The handlebar is an Extralite Ultra Bar in 25.4mm diameter with a 4-degree bend and 520mm width, wrapped with 14-gram ultralight foam grips that feel responsive without padding away road feel. Frame-side details have been refined too: a KCNC carbon stem catcher, Lightworks aluminium stem catch knob in gold, JCP custom carbon hinge clamp with magnetic hold, and various titanium bolts in black and gold anodise throughout. The seatpost clamp is an H&H Innovation design in black, and a NOV Design ultralight magnet hinge clamp in matt black holds everything rigid when folded.

Day to day, this bike behaves quite differently from a stock Brompton despite using the same basic frame geometry. The ceramic bearings throughout the drivetrain and wheelset mean virtually no drag—acceleration feels immediate and momentum builds and holds with ease. The lightweight carbon wheels absorb some road vibration while remaining responsive to steering inputs, making it agile in congested urban stretches. The eeBrake system is notably more modulated than rim brakes, so you can adjust deceleration precisely rather than reaching a point where you have to squeeze hard. The overall riding experience is smooth and efficient without feeling twitchy or nervous.

The bike folds down to the familiar Brompton size and shape, fitting easily under desks, into train luggage racks or car boots. The fold mechanism is crisp and reliable with fresh hinge pins installed and no slop in the mechanism. All components except the wheelset, saddle, crankset, bottom bracket, chain tensioner and stem catch knob are new and unused prior to this build, so there's no hidden wear in brake cables, bearings or contact points.

This build represents a concentration of premium component choices that individually cost over £6,600 in addition to the donor frame itself. The result is a folding bike that performs well beyond what you'd expect from Brompton's standard offerings—lighter, faster to accelerate, smoother to ride and more refined to brake. It suits collectors and serious commuters who value precision engineering and are willing to invest in a bike that simply works better. Worldwide shipping is available at buyer's expense via tracked insured parcel, or collection can be arranged at Durrington-on-Sea station. Within the UK, Parcel Force 24 delivery is included in the price.