How to choose the correct bike type and size?
Do you want to buy a new bike but are not sure how to choose the correct size and model? We prepared a thorough guide to help you.
Considerations before buying a bike
Before buying a bike, there are several aspects to consider. The first step is to choose the type of the bike, which depends on the terrain you plan to use the biike on. From this perspective, there is no all-purpose bicycle. Each bike is suited to different kind of terrain and it is important to consider the future use of your bike carefully. The chosen bike model, rpice and quality should reflect your riding style, expected mileage and predominant terrain on which you plan to ride.
When choosing a bike, take into consideration:
- bike type (mountain bike, cross bike, trekking bike...)
- frame material and the quality of used components
- frame size (in relation to your height)
- components set
- price/quality ratio
Choosing the wrong frame size or adjusting the seat post incorrectly can significantly decrease your comfort during the ride and cause back pain and other problems in the long run.
How to choose the type?
Frequent terrain rides
In this case, a mountain bike is the ideal choice. Mountain bikes have wider tires and rougher pattern which makes it easier for the wheels to adhere to slippery surfaces and keep balance on uneven terrain. You can divide mountain bikes into two categories – bikes with fixed frame and suspension bikeswhich have both suspension fork and suspension frame. Thanks to these features, the user can pedal evenly on unstable terrain and handle riding down difficult slopes. Some suspension bike models have the option of locking both the front and the rear suspension, which is an advantage cyclist who want to ride both in rough terrain and less difficult conditions surely appreciate.
Regular recreational and urban rides
An urban bike, suited for riding on hard flat surfaces, is more than enough for such purposes. Another choice for recreational rides is a trekking bike, equipped with such features as mud guards, lights, a bell or a carrier.
Regular long-distance road rides
A road bike is the correct choice in this case. Road bikes are designed to have an aerodynamic frame, minimal resistance and a prefect force transference. The bikes have only necessary components and their gear shifting is focussed on speed. They are the lightest of all bike types.
Combination of terrain, urban and road rides
In this case you can compromise with a cross bike or a trekking bike. Cross bikes combine the advantages of road and mountain bikes. The seat is more vertical, the wheels have a bigger diameter (28) and the tire pattern is more universal for more sped on tarmac surfaces. If you plan on riding on less difficult terrain, this bike is an optimal choice for you.
Other specialized bikes
Folding bikes, E-bikes, BMX, children’s bikes.
Frames are made of variety of materials - aluminium, magnesium, scandium, carbon, steel and in rare cases titan. The following table offers basic information about the properties of the materials:
Aluminium – The advantage of aluminium alloys is light weight and side frame rigidity. Their disadvantages are low to none flexibility and higher price when compared to steel frames. An important factor influencing the properties of aluminium frames is tube shaping. Aluminium frames are marked alu (possibly with designation 6061, 7005, 7020 etc.), allux, alloy, dural, easton, alutron, etc. The price and weight of these frames depends on the type of aluminium alloy and the method used to produce them.
Carbon – Carbon is made when layers of carbon fabric and glue are moulded under pressure in a vacuum. This method enables the manufacturer to add material where necessary and reduce its amount when not. That’s why the material is at once extremely durable and light. Since the method was perfected, carbon frames have become the number one option for bicycles.
Steel (Hi-Ten) – The advantage of steel frames is their flexibility and low price. However, they are rather heavy. To compensate, steel alloys are used instead, such as Cr-Mo (ameliorated steel with added chrome and molybdenum) or Columbus. Thanks to the alloys’ durability the tubes can be thinner and that makes the frame lighter. The price rises with the quality of the alloy used. Steel is most often used to make BMX frames to ensure durability and impact resistance.
|+ light weight||+ durability||+ rigidity|
|+ rigidity||+ extremely light weight||+ flexibility|
|+ high-quality production|
How to choose the correct frame size?
Frame size (height) is defined as the distance between central axis and the end of the seat tube. Frame size is usually determined in inches (1 inch = 2.54 cm). Frame size of a bike can slightly differ, depending on the brand or frame type. When choosing a bike frame, we recommend taking into account also the length of the user’s legs (third table below). Cross and trekking bike frames can be 1 – 2 inches higher.
Frame size according to the user’s height (adults)
|User height||Mountain bikes (inches)||Cross bikes (inches)||Road bikes (cm)|
|150 - 155 cm||15" - 16"||16"||50 - 52|
|155 - 160 cm||16"||16"||52|
|160 - 165 cm||16" - 17"||17"||52|
|165 - 170 cm||17" - 18"||17" - 18"||52 - 54|
|170 - 175 cm||18" - 19"||18" - 19"||54 - 56|
|175 - 180 cm||19" - 20"||19" - 20"||56 - 58|
|180 - 185 cm||20" - 21"||20" - 21"||58 - 60|
|185 - 190 cm||21" - 22"||21" - 22"||60|
|190 - 195 cm||22" - 23"||22" - 23"||62|
|195 +||23" a víc||24"||62 - 64|
Frame size according to children's height:
|Wheel diameter||Child's age||Child's height (cm)|
|12"||2 - 4||90 - 110 cm|
|14"||3 - 5||95 - 115 cm|
|16"||4 - 7||100 - 125 cm|
|20"||6 - 9||105 - 135 cm|
|24"||8 - 12||115 - 155 cm|
|26"||10 +||155 cm +|
Frame size according to user’s leg length (adults)
Frame size is determined by the length of the seat tube and the seat tube length determines all the other frame dimensions. This size is called “centre-centre”. The general recommendation for choosing mountain bike frame is to have a 5 cm gap between the horizontal frame tube and the user’s groin while standing above the bike. You’ll find recommended frame sizes in the table below. User height is included for illustration purposes.
|User height||Leg length||Frame size|
|Sports use||Recreational use|
|161 cm||72 cm||40 cm||15,7"||42 cm||16,5"|
|165 cm||75 cm||42 cm||16,5"||44 cm||17,3"|
|169 cm||79 cm||44 cm||17,3"||46 cm||18,1"|
|173 cm||82 cm||46 cm||18,1"||48 cm||18,9"|
|179 cm||87 cm||48 cm||18,9"||50 cm||19,7"|
|183 cm||89 cm||50 cm||19,7"||52 cm||20,5"|
|187 cm||92 cm||52 cm||20,5"||54 cm||21,3"|
|193 cm||96 cm||54 cm||21,3"||56 cm||22"|
The components set includes various bicycle parts. These are brakes, stems, pedals, gear shifting, seat posts, cranks, derailleurs, etc. It is best to have a complete components set, without mixing brands or levels. Basically, the higher the quality of the components materials, the higher reliability, adjustability, longevity and also price. The cheapest components are usually made of moulded metal plates or plastic. The more advanced components are mainly made of scandium, titan and carbon. Expensive high-quality components also weight less, which is especially advantageous for longer rides.
Naturally ergonomic saddle position
Adjust the saddle to the correct height. Step on one of the pedals and bring it to its lowest position. You should be able to reach the pedal with your heel. While riding, the tip of your foot should be on the pedal and your leg should be slightly bent at the knee while in the lowest position. Under no circumstances should your hip bones move from side to side. Your hip area should be practically immobile. Seat inclination is adjusted according to the rider’s needs or the bike type. A horizontal position is ideal for mountain, cross and road bikes.