A bicycle with a planetary bush: folding, urban, road or mountain. Owner feedback

A bicycle with a planetary hub is a fairly complex mechanism that consists of more than 40 parts and components. The first vehicles of this type were developed at the beginning of the last century by SACHS and gained popularity among users around the world.

Introduction

Later, the Japanese corporation Shimano and their competitors from the US - SRAM - improved this product and presented the public with four- and seven-speed models. Despite the fact that the planetary bushing has not undergone any particular changes during its history, the increased accuracy requirements that are imposed on its assembly and fabrication are the reason for the high cost of this mechanism. Also to the disadvantages of such a system of switching speeds, in comparison with other solutions, consider its low efficiency at high gear ratios.

Scope of use

Even in spite of these shortcomings, planetary devices are very popular with discerning buyers who choose a folding, city or road bike. After all, the mechanism protected from penetration of moisture, dust and dirt requires minimal maintenance and ensures a long and trouble-free operation, which is combined with the following advantages:

• Bicycles with a planetary bushing are presented in a huge assortment that can satisfy any wishes of riders.
• A wide range of gear ratios provides comfortable acceleration of the bike uphill or on other difficult sections of the road.
• A clear switching of speeds is made with the help of ergonomic dummies on the handlebars. The change of gear takes place even when the bicycle stands still.
• A foldable, road, mountain or city bicycle with a planetary bushing requires minimal maintenance of the mechanisms. Moreover, many instructions indicate that there is no need to carry out routine maintenance for knots and wilset systems.
• Unlike external mechanisms that suffer from accelerated chain wear due to its skewing on system stars, the planetary bushing functions in a different order. In this case, the transmission of the bike consists of only the simplest and most reliable elements, which ensure long-term operation.
• A bicycle with a planetary bushing is equipped with a reliable foot brake.

Design Disadvantages

Of course, the structure of this vehicle is not without some drawbacks. However, their overall impact on the final choice of unsophisticated buyers is too low, because the bike is purchased for everyday use in the city, and it does not have specific requirements. However, discerning critics do not forgive these vehicles any flaws. First of all, they mention a big bike weight, which can cause inconvenience during trips on rough terrain, where bicycles with a planetary bushing are not quite comfortable. The feedback of professionals confirms these theses, since the use of heavy machinery and components in conditions of extreme loads or sports disciplines, where each gram is taken into account, is unacceptable. Also, many cyclists reject the planetary bushing because of the difficulties in servicing - if a malfunction is found in it, it is not always rational to perform expensive repair of the mechanism. Therefore, we will try to understand the design of planetary mechanisms and the features of their application for various needs.

Whim or necessity?

Practically every modern bicycle has a multi-stage transmission. Most often for the bike, an external gear shift system is used - this is a classic design that is easily serviced and repaired. Usually, it allows for switching in the range of 10 to 33 speeds, which provide the necessary gear ratio depending on the conditions. Whereas the internal transmission of a bicycle where a planetary bush is used still remains a wonder, as well as equipping two-wheeled vehicles with a cardan shaft. Nevertheless, for urban comfort bikes, a differential gear is often used, which is recommended for use only in the warm season. Applying budget solutions for year-round or extreme driving will only lead to accelerated wear and tear, and a bicycle with a planetary bushing will require costly repairs. If you stop the choice on the average price segment, you need to be ready to give a two-wheeled "friend" at least 5000-6000 US dollars. In this case, a bicycle with a planetary bush will have a sufficient margin of safety, which will allow the bike to operate daily.

The burden of tradition

An important factor in choosing the optimal characteristics for a city bike is its own weight. If a bushing is installed on it, the reviews mark the shift of the center of gravity of the bike to the rear axle of the wilset. This observation is associated with an impressive mass of differential transmission with a foot brake, which can be up to 2 kilograms. Therefore, the use of this solution in compact bikes is not always justified. After all, they are designed taking into account the characteristics of storage in cramped conditions, and excess weight does not go to their advantage. Therefore, a folding bicycle with a planetary bushing is an anachronism for modern society. It can be considered as a status subject of a cyclic fetish, but not a practical unit for travel.

Options

Consider the main shortcomings of the planetary bushing, which limited its use in this niche:

• High risk of damaging the gearshift mechanism during its intensive operation;
• Insufficient range of gear ratios;
• The significant weight of the sleeve leads to a shift in the center of gravity and an increase in unsprung masses on hardtails and two suspensions;
• The eccentric wheel clamp is incompatible with this solution, since in case of unreliable fixation it is possible to damage the seats;
• Popular frames with vertical dropouts do not allow to take advantage of the planetary hub, and the use of horizontal structures leads to excessive bicycle rises in price.

Results

Despite obvious drawbacks or advantages of this design, the final decision on the appropriateness of its application remains with the buyer. This thesis finds confirmation in numerous reviews of bicycle owners with a planetary hub, which are happy to use their bikes for walks in their spare time.