Whether racing bike or mountain bike: More and more manufacturers are streamlined by the circuits of their models. This has a lot of advantages - but also some disadvantages.
The more corridors, the better. So far, all cycling generations have been safe. Already in the school yard you could argue about a lot, but when it comes to circuit, the number of gears was such an unshakable criterion as the displacement in the car quartet. Three, seven and at some point 21 - nobody doubted that the bike was somehow cool, faster, better. But that's over. Even more: the poles of the bicycle world now seem to have turned, at least with sporty models such as racing bikes, gravel and mountain bikes.
For several years now, a rapid shrinking process has been observed on the treading cranks of new bicycles. For example, if you want to buy a mountain bike and have not dealt with the topic for a long time, you will be surprised when buying a bicycle: Many current models only have two chainrings, i.e. double circuits, or even just simple circuits with a single chain leaf - and usually only eleven or twelve gears.
"All of our new mountain bike models have a simple circuit," says Maik Krienitz, product manager for mountain bikes at the bicycle dealer and manufacturer Rose Bikes based in Bocholt. The trend has recently strengthened again. While the expensive simple circuits were originally only available for high-tech models, they are increasingly prevailing in all price segments. "Two years ago, it would have been unthinkable to do without three-way circuits in mountain bikes in the lower and middle price range," says Frank Greifzu, product manager at the bicycle manufacturer Cube. Today, almost all models have a maximum of two chainrings at Cube. A mountain bike with a triple circuit and possibly still the 26-inch wheels, which is customary up to a few years ago, made it to the classic car within a very short time. This fate also threatens the second chainring with the mountain bike, because large manufacturers such as Shimano or Sram focus primarily on the simple circuit.
Short innovation cycles
The situation is similar with the currently particularly popular gravel bikes. This is a mixture of racing bike and mountain bike - the circuits are also mixed. "The demand for double circuits predominates very clearly," says Greifzu. But here too there are more and more models that are equipped with just one chainring.
Seldom existed with such an important component as the circuit as short innovation cycles as in previous years. This was made possible primarily by new options on the rear wheel: if only six gears were generally space there in the early 1980s, the manufacturers can now install up to twelve pinions there. It was not easy because the chain inevitably runs in the case of more gears - but still does not fall off the pinion and should not wear it quickly. So the chains became narrower and the systems became more sophisticated.
Because more and more pinions can be installed at the back, you need fewer chainrings at the front. This has many advantages for the user. Switching is easier if the derailleur no longer has to lift the chain between three, but only between two chainrings. The chain jumps out less often, and the circuit is also easier to adjust.
The bikes become easier, the maintenance effort is lower
The advantage is even greater if only a single chainring does its job on the crank. The corridors only define the simple circuits on the rear wheel via the different sizes. So it is no longer necessary and of course no second gear lever. "The bicycles are becoming much easier," says Rose product manager Krienitz. In addition, the maintenance effort is lower if the bicycle no longer has an derailleur - what is not on the bike, can not break. "But the biggest advantage is the intuitive shift," emphasizes Krienitz. Instead of dealing with different combinations of chainring and sprocket, you can choose the gears with a single lever.
So everything better? Not necessarily. The absence of chainrings also has disadvantages that are of different weight depending on the route profile and personal preferences. For fewer chainrings, the range between the smallest and the largest gear is often lower than in the previously common triple circuits. In practice, for example, this means that you need more strength on the mountain on steep climbs or that you can no longer accelerate on departures.
Is the spectrum enough?
With the latest, but also quite expensive systems, this no longer applies: a modern simple circuit can even have a larger spectrum than a circuit with several chain leaves. The manufacturers succeed in mounting both very small and very large sprockets with more than 50 teeth on the rear wheel. However, the second disadvantage of the simple circuit then weighs all the harder: the jumps between the individual corridors are much greater. Above all, athletically ambitious drivers, it can then happen that they don't find a suitable gait. One is too heavy, the other too light. For circuits with two chainrings and thus more gears, the gradations are finer. They are therefore still standard for racing cyclists who are strongly based on their optimal cadence. For mountain bikers who drive in rapidly ascending or sloping terrain, however, the big jumps between the corridors can even be practical.
So if you want to buy a new bike, you don't have it easy. One thing is clear: the circuit is one of the most important criteria for buying a bike. "Above all, you should ask yourself what kind of tours you need the bike," says Cube product manager. "The terrain is crucial." The following applies: if you want to trample on a tour at the highest speeds and at the same time climb as easily as possible with steep climbs and are sensitive to the selection of your feel-good movement, you will tend to be a double circuit. This is, for example, "the highly sporty mountain biker who starts his tour flat in the Alpenland with high-speed on the bike path and then heads for his favorite forests," says Greifzu. This type of user is also: "The absolute exception".
The sprocket calculator helps
However, it can also get uncomfortable for the normal driver, especially with steep and longer. The smaller the chainring at the front and the larger the pinion in the back, the easier it becomes. Especially with some gravel bikes with simplications, however, the smallest gear is quite high - which can quickly become exhausting on the mountain. Regardless of whether one or two circuit: If you do not swear or drive high speeds on steep climbs, you should pay particular attention to the translations of the largest and the smallest corridors when buying. And if you want to know exactly how easy a bike climbs or how quickly you can drive it with normal cadence, you have to get the calculator out, use a sprocket calculator on the Internet - or preferably drive extensively.
So it has become more complicated on cranks and rear wheels. However, it was not quite as easy in the past: Because of the many combinations with the sprocks, a few gears are twice occupied or not sensibly usable, because the chain would otherwise run very obliquely. The very large number of gears on the bike has always been an illusion. Nobody noticed that in the school yard.
Of Andreas Remien