Gears And Gear Ratios


Simplistically speaking bicycle gears, a common feature in modern performance biking, help you to give a uniform riding experience no matter what the terrain. Because of the gears you can easily negotiate a steep gradient and increase speed on a downhill beyond the natural wheel roll. It is thanks to gears that performance biking has become an attractive endurance sport around the world

Efficient cycling is all about seamlessly transmitting the effort of the rider’s cadence, which is the rate at which he pedals, to the wheel rotation

To understand gears and gear ratios it is important at first to understand the drive train which is the the composite mechanism of transferring linear leg motion to rotational movement of the wheel. The elements of the drive train are 1. Crank made up of one or multiple chain rings in the front and attached to the pedals, 2. The cassette or the sprocket made up of multiple smaller wheels or cogs and aligned to the rear wheel axel 3.The chain that passes over the chain ring and the sprocket 4 the front and the rear derailer, a mechanism that allows the rider to jump the chain on both the chain wheel and the sprocket and of course 5.the shifters that are the controls on the handlebars

Gearing is the process of altering the position of the chain on the front chain rings and the rear sprockets with the help of the derailer so that the rider can maintain similar cadence or similar effort regardless of the terrain that he is riding on. This is important because the rider can extend his endurance to longer distances and tougher terrains without too much muscle strain

Technical riders take the term gear ratio very seriously as it allows them to pre-estimate the range that their equipment allows them. Without getting into mathematical complexity, simplistically, a gear ratio means the number of times the drive wheel (rear wheel) rotates in proportions to the pedal rotation. For example it would be most convenient if for minimal rotation of the pedal there is maximum rotation of the rear wheel. This ratio is called a gear ratio. Mathematically it is the ratio of the number of teeth in the front chain ring to the number of teeth in the rear sprocket. In case of multiple chain rings and multiple wheels the maximum range or the highest ratio is that between the teeth on the largest chain wheel to the teeth on smallest cog in the sprocket

While pro riders can get into complex calculations, amateurs need to understand this with common sense. Since gear rations come in more handy while negotiating climbs, road bikes normally have two options the standard for the pros (53-39) and the compact for others (50 -34). Similarly in MTB’s, for downhill bikers too much range is of less use since they throw themselves down in any case and let gravity take over and hence the range is less relevant. Whereas for a mountain bikes the preferred range is very high as maximum options are required for tough terrains

So if you are getting into riding its best to know the basic technicalities of gear ratios as it is a great help in selecting your bike. One also has to see it in combination with wheel size etc. And if you are a pro rider it will help if you ask your bike shop for a more professional help. Or you can write into CRANK anytime and our test riders will be glad to help

So cheerio and happy riding and keep em gears movin…

Be the first to comment

Leave a Reply

Your email address will not be published.