Modern bicycles with and without gear shifting can often be found on the roads. And not always a bike without gear shifting is worse than its multi-speed counterpart. For each task, it will be advisable to use one or another model. A quiet walk through the city streets does not impose an increased requirement for the presence of transmissions. But for athletes, a multi-speed bike allows you to save energy and overcome mountainous areas.
Gear shifting – advantages and disadvantages
A cyclist who can reduce or increase the power of the energy transmitted to the wheel will much more easily accelerate the sports equipment on a slope, and pick up the necessary effort on a forest path or in the sand. However, you have to pay for this, a city bike without gear shifting has its advantages:
- Low price;
- Less weight;
- No additional switches on the steering wheel;
- Undemanding maintenance.
Do not think that the transmission without gear shifting is used only for leisurely walks. In the discipline of BMX, athletes compete on bikes that have only one gear. For jumps and other tricks, a multifunctional body kit is simply not required, the reliability of the frame and the curb weight of a two-wheeled sports equipment are much more important.
Bicycle without gear shifting
The advantages of this choice for amateurs are obvious. Especially when you consider that any transport requires constant maintenance. By choosing a bike without shifting gears, the buyer receives huge benefits in service. It comes down to pumping the wheels and periodically cleaning and lubricating the chain. On a single edge, you can opt out of:
- Two stars in the system;
- Five to nine stars in a cassette;
- Shifters and gear shifting systems;
- Ropes and shirts.
It is for this number of parts that the bike becomes lighter. Yes, and you do not have to pay for the purchase of this set of spare parts. These advantages force the largest bicycle manufacturers to produce road vehicles with a single gear. For example, in 2017, KONA released the Paddy Wagon with a reversible hub. By turning the rear wheel over, you can get a different ratio of gears.
The traditional combination of gears on a single-speed bike is 2:1, where one full turn of the cranks causes the wheels to spin twice. Even if the existing ratio seemed inconvenient to the cyclist, he has the opportunity to replace the rear sprocket, choosing the parameters to suit his requirements.
For those who prefer MTB or road bikes, shifting gears on the handlebars will be the most familiar and convenient. There are three options for switches – shifters, shifters, and handles combined with brakes.
- Shifters. There are two levers on each side of the steering wheel.
- Shifters. The round switch serves as an extension of the grips, used on inexpensive models.
- Switches on the brakes. Usually, they are used on road bikes. The specific blend of the steering wheel does not allow the use of shifters or shifters.
It is customary for manufacturers to place gear shifting in the cassette on the right side of the steering wheel, and in the system on the left side. This is because the gears in the cassette are switched much more often, and it is more convenient to do this with the right hand.
Even though additional components and parts require additional adjustments and maintenance, athletes simply need to match the applied efforts to the traffic situation. So, Titan Bike has 2 stars in the system and 8 in the cassette. This means that the athlete receives 16 levels of effort adjustment.
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An even larger adjustment range is used in mountain bikes. Difficult terrain and various types of road surfaces make it necessary to use 3 stars in the system and up to 11 in the cassette. The ratio of gears can reach 500%, which means the regulation of efforts in the five-fold range. To turn the wheel, all other things being equal, in a 1:1 gear, you need to spend five times less effort than with 3:11. But instead of one revolution of the pedals, you have to do five to travel the same distance.
Not so long ago, planetary gear shifting on a bicycle appeared, which combines the advantages of single and multi-speed bikes. Outwardly, it is almost impossible to distinguish a single ped from a planetarium. Only the gear lever on the steering wheel can give it out.
The advantages of such a switch include:
- Low weight;
- Full protection of mechanisms from dirt, dust, and moisture;
- 2-4 times less chain wear due to greater thickness and fewer bends;
- Ease of adjustment;
- Switching can be carried out at idle;
- The uniform tension of the spokes of the rear wheel increases its reliability.
A bicycle with gear shifting in the hub also has disadvantages. This includes a small ratio of gear ratios, efforts vary in a threefold range. Other disadvantages include:
- High energy loss, which reaches a coefficient of 7% versus 2% for the classical scheme;
- High cost, a conventional switch of a comparable class will cost 20% less;
- The laboriousness of removing the wheel, changing the tire, or the camera you will have to tinker.
Despite this, there are a lot of admirers of such a system. Even bicycles for competitions with a planetary hub began to appear.
Automatic gear shift
In 2011, manufacturers began to offer a bicycle with automatic gear shifting, every bike enthusiast can buy SRAM products. By default, they are set to “direct” transmission 1: 1. But when a speed of 12 or 18 km / h is reached, the sleeve itself changes the gear ratio.
So far, two factors have hampered their popularity. The first of these is the price of $90 just for the hub. The second was a small number of passes, of which there are only two – “direct” 1:1 and increased 1:1.37.
Although there are also many advantages:
- Combination with a foot brake;
- No need for maintenance;
- No levers and shifters on the steering wheel;
- Complete dust and moisture protection.
There is no doubt that automatic gear shifting will not hurt the bike. But while progress does not allow the idea to be realized at a high technical level, the machine in 2017 is only suitable for a leisurely ride.
Another direction of development looks more promising – the introduction of electronic components into the transmission. The pioneer was Shimano, which is not surprising. Now the new Dura-Ace Di2 has been released, which will primarily be of interest to professional athletes. They note its highest reliability and accuracy of work.
This is helped by a self-adjusting system that responds well to changing conditions. The disadvantage is the need for a battery, but it’s one charge is enough for several months of intensive use. Although the electric drive made it possible to get rid of the cables, it became necessary to stretch the wires.
But in fact, it is not very important which gearshift system is on the bike. If it meets the objectives, gives pleasure to ride, or helps to achieve sports results, then everything is done right.