Single and Multi Speed Folding Bicycles
How to Choose the Best Folding Mountain and Urban Road Bikes
Jan 13, 2009
Sinclair claims that their 13 pound A-Bike is the lightest folding bike in the world. The Montague Paratrooper is a folding mountain bike and weighs 29 pounds. Which is better? That depends on what the bike is used for.
Wheel Size: Weight versus Comfort and Efficiency
The basic trade-off is weight versus comfort and efficiency.
This is determined mainly by wheel size. Large wheels mean:
- More comfort, rolling over bumps and not rolling into them.
- Higher efficiency, less rolling resistance. The bicycle moves further for every turn of the wheel, meaning less friction at the axle for the same distance traveled.
- Single-chain efficiency. To get the right gearing ratio, some bicycles with small wheels use a set of three gears to drive two chains (Sinclair, Mobiky, E-Z Pack), but this increases the friction.
- Heavier weight and larger size. Large wheels are bigger and heavier than small wheels.
The Sinclair A-Bike has 6 inch wheels. The Montague Paratrooper has 26 inch wheels. The wheels of most folding bikes are somewhere in-between: 16 to 20 inches are popular.
Intended Usage
Some people just want a bicycle that can fit into a car trunk. Weight and size aren't that important. They would prefer a comfortable bike that performs well and can be ridden for miles.
Others need to carry their bicycles into buildings after commuting. Weight and size are important. A short commute means comfort and performance can be sacrificed.
Some commuters carry their bikes on to trains and buses and need to follow minimum-size regulations.
Gearing and Speeds
Just like normal bikes, the gearing of a folding bike will affect the performance.
Single-speed bikes (E-Z Pack, Strida, CarryMe, Sinclair) are more reliable and easier to maintain. They are normally lighter and can be good enough for short commutes.
There are two types of multi-speed gears:
- derailleur gears (Dahon, Montague, Schwinn, Citizen)
- internal hub (epicyclic or planetary) gears (Brompton, Mobiky)
Derailleurs are the gears used on racing bikes. They work well but sometimes throw the chain.
Internal hub gears look like single-speed gears. The gear change mechanism is hidden in the wheel hub. They are more reliable and easier to maintain but slightly less efficient (more friction). Old designs were limited to 3 speeds but new models have 5, 7 or more speeds.
Folding Issues
No matter what the folding mechanism, here's what to look out for.
- Maximum rider weight. The folding mechanism will weaken the bike. Maximum load will be less than the figure for an equivalent normal bike.
- Maximum rider height. Compact folding can also mean limited height. Tall cyclists should check that the seat can be raised sufficiently. Some designs have handlebars that can't be adjusted.
- Folding can mean no space for a bell and front light. They may have to be removed before folding and reattached after unfolding.
- Some designs (Strida, CarryMe, Mobiky) allow the wheels to roll when the bike is folded. This makes weight less important. The bike doesn't need to be carried and can be treated as luggage on wheels when indoors.
- With all the folding and unfolding and carrying around, clothes and hands will touch the oily chain. Covered chains (Sinclair) are useful. Strida uses a greaseless kevlar belt instead of a chain.
Standard Spare Parts
Some parts, especially the wheels, can require repair. Standard parts and sizes means easier repair.
16 to 26 inch wheels are likely to be easily repaired at any bicycle shop. Smaller wheels might have to depend on special parts ordered from the manufacturer.
The Best Folding Bicycle
All folding bikes compromise in one area or another. Deciding which features can be sacrificed is as critical as deciding which features are important.
Not all folding bikes are small and light. Folding tandem bikes are available from Multicycle and Bike Friday.
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