Bicycle Network: Bikes 'n' Bits
Pack small travel fast.If you prefer a bit of origami to pulling off your front wheel everytime you travel, why not try a foldable bike?
Travelling with a ‘regular’ bike can be a pain at times. Manoeuvring in and out of trains, buses, aeroplanes and taxis can be fraught with traffic-jamming anxiety. Several companies manufacture bikes (popularly known as ‘folders’ or ‘foldies’) that fold into roughly the size of a large suitcase – much less unwieldy and cumbersome to transport and store than a standard 700c or 26” machine. Nearly all folding bikes have proprietary frame designs, and wheels of 20” or smaller diameter.
Pros and cons
While a bike that can pack down and then unfold to propel the rider at an average speed of 40km/h is a great idea, there are a few small flies in the ointment.
The case for
- The bike can be packed small for transport in car boots, as airborne luggage, on buses and trams and it can fit neatly into apartments and other small living spaces.
- Folding bikes share many parts with ‘regular’ bikes and parts can often be purchased in ordinary bike shops, with some exceptions (see ‘cons’ below).
- The low standover height of most folding bike frames makes them ideal for people of average and shorter leg lengths.
- Smaller (lighter) wheels can be accelerated easily, which also helps in hill climbing. Frames often do not weigh much more than standard bikes.
The case against
- The suspension and folding arrangements of smaller-wheeled bikes, which are necessary for rider comfort, have joints, sliders, bumpers and pivots that wear with use. This wear produces unwanted lateral movement. The lack of a solid structure could lead to accelerated fatigue (and possible breakage) in poor quality components.
- Many designs of folding bikes have long, unsupported frame elements for handlebars and seats. Bending and twisting of structural elements under load is one of the prime absorbers of power input.
- Small wheels are necessary for small pack-down size, but don’t deal well with potholes, and tyres and tubes are often not readily available.
- Many folding bikes are built on the dictum ‘one size fits most’. This is fine as long as you are not taller than about 6’3” (190cm).
- Gearing with small wheels is lower. To accommodate this, you need oversized chainrings (unwieldy), and the necessarily small cogs needed to transmit drive effectively are easily worn.
Moulton is the oldest of the brands we reviewed and has stood the test of time. The FX8 sits at the middle of the English-made range. Although not primarily a folding bike, its triangulated spaceframe construction can be unbolted to make the bike smaller, and the bike’s small wheels make it easy to pack for travel, although this process takes longer than the other bikes reviewed.
Birdy Monocoque Anthracite 9
The new Birdy monocoque frame has more strength and looks better than previous models, while being as easy to pack. The Anthracite model has Shimano Deore LX and XT parts, which lend reliability and ruggedness to a sound design. Birdys track well over rough surfaces with their spring/elastomer suspension and they are the only folding bikes that do not fold in the middle of a main frame member, which is good for reducing frame and component fatigue.
Brompton’s under-15-second fold time, ease of use and their small folded size make them ideal for use and storage in a crowded urban setting. Their forté is small urban hops, but they can extend themselves for longer rides if the situation demands. The M3L sits in the middle of the range, with three gears and a more relaxed riding position than other models. Internal hub gears keep maintenance simple.
Dahon Speed P8
Dahon, a Taiwanese company, makes an extensive range of bikes using slightly unconventional designs. Dahon’s folding range of bikes has high-quality components including steel and aluminium frames, hub and derailleur gears. The P8 uses derailleur gears and a Cro-Moly frame with a stripped-down specification for light weight, stiffness and strength. They come into their own in densely populated and neighbourhoods.
Folding bikes FAQ
Derailleur or hub gears?
Configuring gearing systems for folding bikes must cause a fair bit of head scratching. Hub gears potentially avoid the problem of long chain runs of derailleur gears and, crucially for travelling, eliminate fragile external parts. Integrated rear brakes in geared hubs are more reliable in bad weather, and less likely to be knocked out of adjustment during transit. However, hub gears concentrate weight in the rear wheel of the bike, and are difficult to mend if something does go wrong in, say, Uttar Pradesh.
Wheels with a 16, 17, 18 and 20-inch diameter are all common on folding bicycles. But which is the best choice? For high-quality tyres that roll well, puncture rarely and are readily available away from specialist dealers the 20” format is generally recommended. However, this should not be the sole criterion for bike choice, as spare tyres and tubes are fairly easily carried on longer trips.
Do you need suspension?
Yes, it is advisable to have good suspension on small wheel bikes, so you can comfortably roll over different surfaces. The bikes reviewed here use different systems, but compared to high-end mountain bikes, the suspensions systems are basic.
Which bike for which ride?
The Brompton, the Birdy, the Moulton and the Dahon all reviewed here are convenient and practical, focusing on fitting cycling into a crowded urban lifestyle. The new Birdy frame is designed to aid touring and increase the bike’s speed. All manufacturers featured have an extensive range of bikes in many different component specifications, and several different frame designs. Bike Friday is another well-known brand folding bikes not reviewed here.
Mark Horner ends many days with grease smears on his face. He divides his time between fixing bikes and supporting rides. When he’s not working on or around other people’s bikes, you’ll find him out riding his own.
|Model||FX 8||Monocoque Anthracite 9||M3L||Speed P8|
20" x 1.25"
|18" x 1.5"||16" x 1.25"||20" x 1.5"|
|Frame sizes||One size||One size||One size||One size|
|Frame material||Cro-Moly steel, Reynolds 531 head and seat tubes||7005 alloy moncoque||Cro-Moly steel||Integrated, Patented Fusion Technology|
|Fork||Moulton Unicrown Reynolds 531||Leading link, suspended||Cro-Moly steel||Intergrated, Patented Fusion Technology|
|Brakes||Tektro Quartz V-brake||AVID Single Digit 7||Dual pivot, F&R||Kinetix SpeedStop V brakes, stainless link and anchor bolt, "silentGrip" ceramic brake pads Avid leavers|
|Shifters||SRAM Centera Twistgrip||Shimano Deore LX||3-speed SRAM||8-speed SRAM|
|Derailleur - front||N/A||N/A||N/A||N/A|
|Gears - rear||Shimano Sora||Shimano Deore XT||3-speed SRAM internal||8-speed 11-34T|
|Crankset||Stronglight 48T||Sunrace 170mm||Alloy||Truvativ Touro|
|Bottom Bracket||SKF sealed cartridge||BB-7418AL 68-113mm JIS||sealed cartridge||sealed cartridge|
|Chain||Taya||Shimano CN-HG73, 114L||1/2" x 1/8"||KMC Z51|
|Pedals||VP resin plus toeclips/straps||VP-197 in sandblasted silver||L/H folding||Suntour folding|
|Stem||JD-337 alloy, front-loading, 100mm ext.||Adj, height, new design 25° angle||Integrated||Radius Telescope™, forged-aluminum, patented InSide™ lock|
|Handlebar||ITM 'moustache' bar||Alloy||Alloy 100mm rise||Ritchey 6061-T6|
|Front hub||Pashley/KT QR||Mount, sealed bearing||Alloy Q/R||Kinetix Neutron|
|Rear hub||Pashley/KT QR||Shimano Deore LX||3-speed SRAM internal||8-speed Kinetix|
|Spokes||14G, stainless, brass nipples, 36 F&R||Richman 14G 2mm stainless steel||Stainless steel||14G, stainless steel, brass nipples|
|Rims||Rigida AS26FL 406mm||Alex DA-16 deep section||Alloy||Kinetix Comp, doublewall, CNC-machined sidewalls, wear line indicator|
|Tyres||Schwalbe Marathorn Swift 20 x 1.35"||Maxxis kevlar 90PSI||Brompton, Schwalbe Stelvio||Schwalbe Big Apple 20" x 2.0" 70psi, 67 tpi|
|Seatpost||31.8 mm diameter, 400mm long||AL7075 34.9x570mm||Steel, Titanium opt.|
|Saddle||SMP 1265 Elastomer||Velo VL-2038 with Cro-Moly rails||PU, Fizik opt.||BioLogic™ Comfort, Ozone design, patented DualDensity™ base|
|Freewheel||SRAM 5.0 8spd 11-28||Shimano Deore LX 11-32T||N/A||16T Shimano|
*All models reviewed come in one frame size only.
This article first appeared the June-July 2006 issue of Ride On.
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