2 types of transmissions
There are 2 main types of transmission, each with their advantages and disadvantages..
Petit Porteur frame is compatible with both types of transmission.
Hub Gears for bikes
this type of transmission was invented before the derailleur and is common in the nordic countries of europe.
In this transmission, the hub has only one pinion. The modification of the reduction ratio is achieved through a set of gears inside the hub.
The gear change is effected by a handlebar handle which modifies the reduction ratio of the gears in the hub (like the gearbox of a car).
The integrated gear hub is a complex but reliable mechanism. the mechanism is protected in the sealed hub. It requires very little maintenance, but this will preferably be entrusted to a bicycle repairer.
Even if some models accept shifting at full pedaling power, it is advisable to reduce the force exerted on the pedals during shifting. This transmission offers the enormous advantage (especially in cities) of being able to change gears when stationary.
Because there is only one sprocket, it is impossible to derail.
The weak points being a performance penalized by the set of gears and a higher price than a derailleur.
Bicycle external drivetrains
This is the type of transmission found on most bikes in France. A derailleur moves the chain on a cassette comprising between 7 and 11 sprockets. Moving the chain from one sprocket to another must be done by limiting the force exerted on the pedals, but can only be done by moving the bike and turning the crankset.
This type of transmission offers the best possible performance because the chain is in direct contact with the wheel it rotates.
Derails are found both on entry-level bikes (because of its low price on the low-end), and on racing bikes worth several thousand euros (because of its performance).
The gear change is achieved by a handlebar handle that moves the derailleur, and therefore moves the chain on the sprockets.
The derailleur is a simple mechanism which you can easily adjust yourself.
Our preference is for hubs with internal gears for their following advantages:
- Shifting possible even when stopped
- Inability to derail
In urban use, try the hubs with internal gears and you will not want to change any more
You will also find on the Internet many articles and discussions on forums dedicated to bikes because this question comes up frequently.