Let’s start with the concept itself. What is a planetary gear application? If you consider it not in terms of kinetic mechanics and the resistance of materials, then everything will be much easier than it seemed. Planetary is a gearbox that consists of a fixed element (sleeve axis), a driving element (a star-driven by a chain), and a driven element (sleeve body). The number of gears depends on the gear ratio and the number of teeth on each element of the planetary gearbox. It’s simple.
Advantages and disadvantages of bicycle
Planetary have a number of advantages, about which it is a sin to keep silent:
- Gear shift mechanism is ideally protected from aggressive media;
- Transfers can be switched while parked, which is a big plus when driving around the city;
- Very easy to use – one shifter and there is no risk of falling into the “forbidden zone” of gear shifting;
- The presence of one star allows you to install a casing to protect the circuit from external influences;
- The ability to use more durable chains from one-speed bikes.
According to these advantages, the type of bicycle immediately emerges, where the planetary hub asks. But let’s not get ahead. Now about the shortcomings of the planetary gear:
- Very high cost compared to external switching systems;
- High probability of breakage of gears with aggressive driving style;
- The narrow range of gear ratios;
- A large number of gears leads to a decrease in efficiency;
- The inability to repair “on your knees”;
- Incompatibility with eccentric wheel clamp.
The mechanism of the planetary machine was invented and implemented not yesterday. And not even the day before yesterday. Back in the early twentieth century, the first two-speed bicycles with a planetary hub traveled along the roads of England. They since 1902 successfully collected the firm Sturmey-Archer. Now such sleeves put on bikes class “comfort” and they are very popular among the burghers of Western Europe.
Manufacturing technology center
At present, very few manufacturers can afford the assembly of planetary bushings due to complex manufacturing techniques. Among them are such giants of the bicycle industry as Shimano, Sram, Rohloff. There are plankarki and under the usual V-Brake, and under the disc brakes. They even produce options with a foot brake, like a one-speed bicycle.
Consider a few, if possible different, planetary bushings and features of their use on a particular bike.
Best city bikes
Using the Pride Comfort Men’s 28 ” bicycle as an example, we will consider the aspects of using the Shimano sg-3c41, 36h planetary hub. The bike is designed specifically for comfortable daily movement within the city. The bike is assembled on an aluminum frame and equipped with a rigid fork. The standard equipment includes aluminum footboards, trunk, full-size plastic fenders. And Pride would not be himself without a beautiful appearance with stylish steering bends but without the loss of “masculinity” in appearance.
Planetary body types
The rear hub, to which we are approaching, is a 3-speed, planetary type with a foot brake called Shimano Nexus Inter-3 sg-3c41. Since the gear shift occurs inside the sleeve, such a system can go without maintenance, almost 50,000 km. Very well friends with the foot brake audience, which is accustomed to such a system of brakes. But it is worth remembering that braking with one wheel is often ineffective. Therefore, this model is equipped with a front brake – the usual rim. Bicycle with a planetary hub uses the simplest and very reliable, almost eternal chain for a single-speed transmission.
The hub has a steel case, which of course affects its weight – 1175 g, but for a comfortable bike, this is not the main thing. The instructions for the sleeve generally indicate that it is maintenance-free. It sounds soothing.
We now turn to another type of bike – folding.
Folding bicycle reviews
Folding bike with the Comanche Logo planetary bushing in the city, like a fish in water. Lightweight, very practical for megacities. The bike folds very quickly and compactly. Without haste, disassembly takes less than 20 seconds. If necessary, you can take it with you in public transport or pack it in the trunk of a car.
The rear hub on it is already familiar to us from city bikes, the Shimano Nexus Inter-3 sg-3c41 with three speeds.
Mountain bike rear shock bushings
With great difficulty, but still managed to find even a mountain bike with a planetarium (although this is very rare).
Volume Generator is not just a mountain bike; it is a work of art. It is executed as a symbiosis of a one-speed bike and MTV. On the device installed planetary Affine, two disc brakes.
Looking away from the bike, let’s return to the Shimano Affine SG-S700 hub. This is one of the latest developments of the company with 11th (!) Speeds. The new sleeve has received the appropriate design, switches not only gently but also quietly.
In principle, the objectives of the brief review we have achieved. The bike on the planetary hub, of course, has a bright future. Judging by the speed of technology development, soon we will not seem like a fantasy extreme bike with a planetary gear.