REAR WHEELS IN TRACTOR ARE BIGGER THAN FRONT WHEELS !! WHY??

The word “tractor” is related to words like “traction” and “tractive,” from the Latin word “tractus” meaning drawing (pulling): a tractor is essentially a machine designed to pull things along, usually very slowly and surely.

Reasons for having big wheel at rear and small ones at front:

1.Grip or Traction

Farm tractors spend a lot of their life working in muddy, bumpy fields. If you’ve ever been in car that has driven over a muddy field, you will know that the car slips around on the surface of the mud, or it gets stuck. A large tyre on a tractor has much better grip pads that can ‘bite’ into the ground, as well as a large surface area that distributes weight more evenly which means the traction is a lot better. 

2.Steering

The two smaller wheels at the front have a much better steering radius which means it’s easier to turn sharp corners. This is really important to cover the maximum area of the field while carrying out different jobs like ploughing, sowing and harvesting. Being light weight and small is also really beneficial for ease of control.

3.Visibility

The large rear wheels of the tractor fix the driver’s seat at a higher elevation which ensures good visibility of the nose of the tractor and the corners of the field it ploughs.

4.Cost

Small tyres cost less than larger tyres, and therefore it is much cheaper to replace small tyres that the very expensive big ones! It’s worth noting that because the rear tyres have a much thicker tread that they don’t need to be replaced as often as the front ones.

5.Weight distribution

Having the driving axle higher above the ground means the tractor can pull more weight without the front of the tractor rising up. It works like a lever, where twice the height means twice the maximum pulling force before the tractor tips over.

INTAKE VALVE BIGGER,EXHAUST VALVE SMALLER !! KNOW THE REASON !!

In internal combustion engines, intake valve is used to introduce fresh charge to the cylinder and exhaust valve is used to expel burnt gases from cylinder.

Generally,intake valve is bigger than exhaust valve.The reason is explained below :

1.)The intake valve is bigger in size so that sufficient amount of charge can enter into cylinder as pressure outside is low.

2.)As the pressure after power stroke is high enough to push exhaust gases outside.So in the case of exhaust valve small opening is given.

3.)Being smaller also assists exhaust valves with keeping them cool which is important as exhaust valves often give rise to thermal problems.

KNOW WHY FAIRING IS PROVIDED IN ALL RACING BIKES !!

A motorcycle fairing is a shell placed over the frame of some motorcycles, especially racing motorcycles and sport bikes, with the primary purpose to reduce air drag. The secondary functions are the protection of the rider from airborne hazards and wind-induced hypothermia and of the engine components in the case of an accident.

Motorcycle Fairing is important and it does play a major role in reducing Air blast while traveling at high speeds. In this article,we will compare “Faired” motorcycles with their “Naked” counterparts. Thus, we can easily judge the difference which the fairing makes.

Why fairing is added to racing motorbikes:

The major benefit of a fairing on sport touring and touring motorcycles is a reduction in aerodynamic drag, which allows for reduced fuel consumption and permits higher speeds at lower engine rpm, which in turn increases engine life.

Let's understand by an example:

Suzuki Motorcycles India had introduced an awesome bike called Gixxer, the 155cc Motorcycle made its debut in 2014 and had superb handling, punchy performance and awesome looks. The bike was capable of a top speed of around 117 km/hr but felt a little wobbly at High speeds. After a little while, Suzuki Motorcycles India launched Gixxer SF, which was the fully faired version of the bike.

The Engine of the bike remained the same 155cc unit and even the weight too propelled by 4 Kgs. Despite all that the Gixxer SF was easily able to score a more stable highway run High speeds. The fairing provided decreased wind drag and increased aerodynamic stability at high speeds. All of these factors also contributed to the improved Fuel-economy of the Gixxer SF.

Some disadvantages of fairing :

>Low ground clearance:
Fairing often reduces the Ground clearance as it takes up a huge chunk of space, below and sideways of the engine.

>Limited Flick-ability:
A fairing reduces your bike’s flick-ability as the heavy structure at the front, prevents you from cramming your bike into tight spaces.

>Increased maintenance cost:
Most of the fully faired bikes don’t come with a leg guard because the fairing takes up all of the space, so there is none left to install a leg guard. So, just one little accident or crash is enough to cause a big crack or scratch on your bike.