The in and out of Gears for a mountain bike
Alison Addy
This article gives us a brief picture of the gears for a bicycle, its importance and how best can we make use of them.
Mountain bike gears keep becoming very intricate. Today's bikes have as much as 27 gear ratios. A mountain bikes make use of a combination of a three differently sized sprockets in the front and nine at the rear to make gear ratios.
The thought behind these gears would be to allow the biker cranking the pedals at a consistent pace irrespective of the kind of slope you are on with the bike. This can be better understood by imagining the bike with only one gear. Every time you rotate one turn of the pedals the rear wheel would also rotate for one turn, the gear ration being 1:1.
If your rear wheel is of 26 inches in diameter, then with a gear ratio of 1:1, a full pedal twist would have the wheel cover 81.6 inches of the ground. If you pedal at a 50 RPM speed, this would mean that your bike can cover around 340 feet of the ground in a minute. This is equal to the walking speed which is just 3.8 MPH. This would be ideal for riding a steep hill but, it not good for going downhill or ground.
You require a different ratio for going fast. To go downhill at the rate of 25 MPH with a cadence of 50 RPM at your pedals, you would need a gear ratio of 5.6:1. Any bike with more gears would give you much number of increments from a gear ratio of 1:1 to a gear ratio of 6.5:1 that help you to pedal always at 50 RPM irrespective of the speed you are actually going.
It is difficult to observe any difference between the six of the gears that are very close each other on a common 27 speed mountain bike.
When you use in real, bikers usually tend to select a front sprocket that suits the slope they ride on and they stick to it, though it is very difficult to shift the front sprocket under heavy load. It is however very easy to shift the gears between on the rear.
If you wish to ride up a hill, it is always best to select the tiniest of the sprockets on the front and then shift between the available nine gears on the rear. You will more advantage if you have more speeds on the back sprocket.
Gears on the whole dictate the overall speed of your bike and hence are very important for mountain bikes. You would neither be able to build up speed nor would be in a position to pound the pedals without the gears. It is gears that help you in moving the pedals and also gaining speed. Before choosing a bike you must see the (
http://www.bikecyclingreviews.com/road_bikes.html ) Road bike review to get an idea of it.
You get all kinds of gears in mountain or road bikes, and all of these gears would help you in building a lot of momentum, if used in the correct way.
Alison Addy is a freelance writer for
http://www.bikecyclingreviews.com .Keep reading about (
http://www.bikecyclingreviews.com/road_bikes.html ) road bike review and bike gears at his web.
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