Brompton G Line hero image

Brompton goes bigger: new upsized G Line aims to be ‘the most versatile bike in the world’

The new, go-anywhere folder also becomes the first Brompton with hydraulic disc brakes

Photos: Brompton Words: Simon Smythe

When Brompton says this is its biggest launch in 50 years, it’s not lying. Until now, all Bromptons rolled on 16in wheels, including special editions such as the CHPT3 collaboration with David Millar's brand. Now, the British brand says, “Brompton has rewritten the rules again with the G Line, which offers the feel and ride of a ‘big wheel’ bike, while maintaining the convenience and versatility of its signature fold.”

With new geometry, 20in wheels with custom Schwalbe tyres, hydraulic disc brakes and Shimano Alfine eight-speed hub gearing, Brompton says the new G Line provides game-changing comfort and capability to ride as far as you want to go, over multi-terrains, beyond the city in full comfort. The new model, which includes an Electric G Line e-bike version, is “holistically designed around the fold that made Brompton famous”. It has a steel frame that’s handmade in the brand’s London factory and comes with a seven-year warranty.

But why change the wheel size that defines the British brand – isn’t this literally reinventing the wheel? Brompton’s CEO, Will Butler-Adams, says: “Brompton owners are passionate about their bikes but it has always been a bike optimised for cities. Now, as more and more people look to escape the city, exploring roads and trails less travelled, it was the right time to take everything that makes the Brompton so special, and make it capable of going beyond the urban environment and into tougher terrain.” 

Brompton G Line bikes on gravel

The 20in wheel size is commonly used by other folding bike manufacturers – both standard and electric – and it’s highly likely Brompton simply decided that it wasn’t worth not including bigger wheels in its range for their faster, smoother rolling over rougher ground.

There were rumours more than two years ago that a 20in Brompton was being developed and a prototype was spotted more recently, so it adds up when Brompton says the bike has been rigorously tested over 250,000km to meet industry (and its own) standards, ensuring it could tackle everything from dusty singletrack to rain-soaked cobbles.

A man wheeling a folded Brompton G Line in a tube station

Like its 16in stablemates – which remain in Brompton’s range – the G Line can fold down in under 20 seconds (dependent on the user's skill). When folded, the G Line measures 690mm x 730mm x 402mm. Since folded dimensions of course depend on wheel size, it’s bigger than a classic 16in Brompton, which measures 585mm x 565mm x 270mm. When folded, however, the G Line behaves like all Bromptons and can be steered with the saddle or towed with the handlebar like a wheelie suitcase.

There are three sizes on offer, small, medium and large, suitable for riders from 152cm to 198cm, based on a single frame size but differentiated via different stem lengths. Brompton says the geometry/sizing was developed with a world-leading bike fitting expert for the best ride experience. 

A man riding a Bromton G Line with mountains in the background

Brompton quotes the weight as “from 13.9kg”, which makes the G Line the heaviest model – probably unavoidable given it has a steel folding frame with disc brakes and bigger wheels. The most basic standard Brompton, the A Line, weighs around 11.6kg while the top-of-the-range titanium T Line weighs 7.95kg.

The G Line comes with Brompton’s Wide Platform QR Pedal Set, which the brand says is the grippiest, most comfortable, stable pedal for riding on all kinds of ground. The left pedal is removable and can stow behind the fork to reduce the fold dimensions further.

There’s a riser bar that Brompton describes as “wide… delivers exceptional stability – from leverage on uphills and rough ground to comfort on longer rides. Expertly engineered to fit inside the fold”. The bar comes with new Brompton Ergonomic Grips aimed at providing extra cushioning and support.

Two Brompton G Line bikes folded on the beach

The Brompton Superlight Saddle that comes with the G Line has a carbon base for vibration damping and also a carry handle under the nose, designed to make lifting and rolling the folded bike easier. Customers can choose between two tyre options: custom made Schwalbe G-One or Continental Urban Contact for city riding on tarmac.

The Electric G Line features a new 250-watt rear hub motor that Brompton says ensures superb stability and traction on all ground throughout three levels of assistance. The brand also says it has been rigorously tested in real world conditions and in the lab, where its components have collectively travelled the distance to the moon and back on a 24/7 durability rig, with 20-plus motors going through a combined mileage of over 1,000,000km. It uses a 345Wh battery that Brompton claims allows riders to explore from 20-40 miles (30-60km). The battery pack can be removed with one click for charging away from the bike. 

Brompton has also launched a range of G Line-specific accessories so that owners can run a rack, mudguards, a variety of bags, add water bottles and store a toolkit inside the frame. Additionally, Brompton’s existing bag range is compatible with the G Line.

Models, Colours and Pricing

  • G Line 8-Speed - from 13.9kg in size Small 
  • G Line 8-Speed with rack and mudguards - from 14.8kg in size Small 
  • Electric G Line 4-Speed with rack and mudguards - from 16.1kg without battery, 19.5 kg with battery in size Small.

All models available in Forest Green, Adventure Orange, Traildust White

  • G Line 8-Speed £2,399
  • G Line 8-Speed with Rack and Mudguards £2,499
  • G Line 8-Speed with Lights £2,489
  • G Line 8-Speed with Lights and Rack £2,589
  • Electric G Line 4 speed £3,499

The Brompton G Line is available from October at www.brompton.com, Brompton Junction stores, and selected Brompton Accredited Retailers across the UK and Europe. We have one on its way for review, so keep an eye out for our opinion.

Simon Smythe staff banner
Photos: Brompton Words: Simon Smythe

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