Getting a frame that fits you well is one of the most important things when choosing a bike, as the frame size
will affect its feel and comfort. Despite various specialist fitting services on the market these days, following a few basic principles around sizing should suffice for the general commuter. Most of your weight on the bike should be carried by your feet and bottom, not by your hands.
Most bike size measurements are based on the seat tube length (the vertical bar from the pedal cranks to the saddle). Make sure you can stand over the bike with some clearance.
For optimum saddle height
, place your heel on the pedal – when it’s at the bottom of the stroke, your leg should be straight. When you move your foot into the normal pedalling position, you’ll have a slight bend in the knee.
The length of the top tube (seat to handlebars) is also key as it determines how far you’ll have to stretch. There’s no simple guide but comfort is crucial – you don’t want to be too stretched out or too bunched up.
What the frame is made out of will also impact your ride.
Common on classic bikes such as the Dutch step-through
Pros: Absorbs bumps; strong
Cons: Rusts easily; can be heavy
Common on city-style bikes
Pros: Lighter than steel; doesn’t rust
Cons: Doesn’t absorb bumps
Not common on city-style bikes
Pros: Light; absorbs bumps