Brompton Bicycle
The Brompton is a British folding bicycle. Due to its compactness when folded, it is popular among commuters especially in the UK, the Netherlands, and Japan. Fast and compact folding is seen as the Brompton's key competitive advantage. The design has remained fundamentally unchanged over three decades, although it has been steadily refined.
History
The idea of folding bikes is not new now and was not new in 1976 when Andrew Ritchie, an engineering graduate but a landscape gardener by trade, decided to try his hand. Contemporary folding bikes from Bickerton in particular had shown that a market existed, but the quality and utility of the product left much to be desired.
Ritchie obtained financial backing from a few friends and founded a company named after the Brompton Oratory, the famous London landmark, visible from Ritchie's flat where the first prototypes were built. Initially he sought to license the design but in the end the drawbacks of this approach outnumbered the advantages and after five years, and a further five of searching for venture capital, the idea remained on the drawing board. Finally Ritchie decided to go it alone and with the backing of thirty friends who paid up front to buy the first production run he began manufacturing the bike himself.
The bikes were well received, others started enquiring, and with rudimentary tooling and as much enthusiasm as expertise the Brompton Bicycle company was in business.
Enthusiasm and hard work were enough for the firm to break even but further capital would be required to expand. Despite the fact that around 500 bikes had been sold, no venture capitalists were interested and production ground to a halt in 1982. However, the company was still solvent, there was still demand for the bikes and Ritchie was convinced that the product had a future so he continued to explore possibilities while doing various other jobs to make ends meet. Finally in 1986, again with backing from friends and former customers (notably Julian Vereker, founder of Naim Audio), enough money was raised to resume production on a larger scale in a railway arch in Brentford. By early 1988 Brompton bicycles were once more in production.
In the years since, the firm has grown to be one of the best-known brands in the UK. The order book is full and a host of imitations have been spawned. The bike has earned a strong following at home and abroad, earning a Queen's Award for Exports in 1995.
Brompton is one of only two mass-production bike builders left in the UK (the other is Pashley). The company makes one product, the design fundamentally unchanged from the original, but much improved over time. Recent developments include optional part-titanium frames, new styles of handlebar, rather better trolley wheels (see below) and a menu approach to specification, with buyers able to mix and match options and colours.
About the bike
All Bromptons are basically the same: a characteristic curved main tube with a hinged rear triangle, three-speed hub gears and/or two-speed derailleur to give two, three or six speeds, small (currently 16") wheels, a tall seatpost and a folding handlebar stem. The handlebars are aluminium, traditionally a moustache shape (though with a deep U). There is a hinge in the main tube. In riding position the rear triangle rests on a rubber spring to give some suspension; it is held in place by the rider's weight. On the left is a custom folding pedal. On the right is a standard pedal. Mudguards are fitted as standard (unless de-selected), an optional rack and factory-fitted dynamo lighting are also available. The dropouts are narrow, which enables the small folded package, but also restricts the range of compatible gearing and hubs, although Schmidt Maschinenbau now manufacture the SON XS hub dynamo for the Brompton. In addition to the frame and dropouts, many other parts are also unique to the Brompton, including brake levers, rear derailleur, chain tensioner, and handlebars.
The bike is surprisingly rigid given the length of stem and seat pin. Heavy or powerful riders might find the rear suspension disconcerting, but it does dampen bumps, helping avoid pinch punctures that heavy riders sometimes experience.
Specifying and buying
A test ride is strongly advised before buying, particularly to check gearing preference. The Brompton is fairly expensive (prices range from £380 to around £1200) and particularly fit for purpose, so most buyers do their research thoroughly and get the right bike first time. Bromptons are exceptionally reliable and long-lived. These characteristics mean that depreciation is lower on Bromptons than many other bikes.
Two main equipment options are available, one which comes with a rack and bottle dynamo lighting system, and one without. Both are available in three and six speed versions, and now with titanium rear triangle, forks and seatpost for a weight saving of around 2 kg. For riders over about 1.85 m (6') tall an extended or telescopic seatpost is available. There are Brompton riders 2 m (6 ft 7 in) tall and more. The deep moustache bars are somewhat flexible - earlier models were prone to fatigue failure and the tube was subsequently thickened - and a brace is available for those who find this problematic.
A range of special luggage is available: panniers and a messenger bag, which mount on a quick-release block on the head tube; a trunk bag which mounts on the optional rack; a saddle bag.
Experienced cyclists usually recommend the 12% or 18% reduced gearing option. The standard gearing is suited to a slow pedalling cadence. Consensus is that faster cadence is efficient and less stressful to the rider's joints. The simple suspension tends to "bob" a little under load - the two most common fixes are a pair of jubilee clips around the rubber spring or replacing it with an elastomer from a Riese & Muller Birdy. Dual-pivot caliper brakes are now fitted as standard front and rear (replacing the high-leverage brakes formerly fitted as standard at the rear).
For the traditionally-minded there is an optional Brompton branded Brooks traditional leather saddle (as seen in the pictures with this article); sportier models can be equipped with a fizik vitesse saddle. Although the supplied plastic and foam saddle is light and cheap, it is widely regarded as uncomfortable over longer distances.
Folding
The fold is in four stages. The fact that the bike stands unsupported at each stage of the fold is a strong selling point, as is the fact that the bike can be folded and unfolded in 10-20 seconds by a proficient rider. The two hinges, on the main tube and the steerer, are secured by clamping a thick machined aluminium channel over them and fastening a wing-bolt with a large plastic handle. Folding is accomplished standing on the left side of the bicycle, from the rider's perspective. Before folding the luggage must be removed (panniers are quick-release).
First, the front wheel is turned slightly left and the rear triangle flipped under, the wheel touching the bottom of the main tube. The bike sits reasonably securely on the front wheel; two small wheels which are mounted above the rear light/reflector bracket on the rear triangle; and either a small trolley wheel on the mudguard or two wheels on the back of the rack, if fitted. At this stage the pedals may be freely rotated; the right pedal should be rotated to around the seven o'clock position, that is, low and behind.
Second, the main tube hinge is unlocked; the head tube is grasped and the front wheel swung back (still facing forward) and hooked to the rear triangle with a hook mounted on the left fork.
Third, the saddle is dropped down. There is a quick-release seat pin clamp; a new design is being introduced in conjunction with the new rear frame latch (see above) to replace its relatively cheap-looking predecessor. The seat pin is long and projects far enough down that it locks the rear triangle in place. On newer bikes with free-rolling trolley wheels a rubber foot on the bottom of the seat pin stops the bicycle rolling when folded (like every development with Brompton, this is available as a retro-fit). The seat pin in ployed position rests against the rear tyre, thus locking the rear triangle securely.
Fourth, the handlebar stem clamp is unfastened and the bars simply drop down into place; a clip on the right fork leg secures the handlebars to the bike. Some riders reverse the order of stages three and four.
The folded package is 565 mm x 545 mm x 250 mm (22.2" x 21.5" x 9.8) and weighs between 9 and 12.5 kg (20-28 lb).
Once folded the pannier can be re-attached to its block and the integral handle used to trail the bike like a piece of wheeled luggage.
Brompton Culture
Being an unusual bicycle, the Brompton has inspired a devoted following. Brompton fans with engineering expertise have not been slow to modify the bike; the most notable of these is Steve Parry whose SP Brompton includes a 7-speed derailleur, V-brakes, carbon fibre seat post and suspension handlebar system. Parry will incorporate any or all of the above to suit the customer's requirements and budget.
The compact dimensions of the folded bike allows easy transport in buses, taxis, tubes, trams and main line trains where carrying a normal bike can be difficult.
Superficially the bike is not well suited to long rides, having a restricted range of gears, but with an upgraded saddle it is comfortable enough to undertake ambitious journeys.
Alternatively, the cycle engineer Juliane Neuss in Germany designed a commercially available add-on kit which turned the Brompton into the first true folding recumbent.
An electric-assist hub motor kit ('nano') adds a 4-5.5 kg to the weight depending on the size of battery. It was reviewed in issue 60 of 'A to B' magazine. On the test route, it ran for 75 km over mixed terrain at an average speed of 22 km/h with a 7Ah Lithum-Polymer battery. The hub is 100 mm wide, so wider forks are required, along with a modified luggage block which connects to the battery inside the luggage.