A Rethymno ATV tour is an outing on a quad bike or a similar off-road vehicle near the town of Rethymno on Crete. Read on for the vehicle types, the engine, the belt drive, fuel injection, the chain and the radiator, then four plain answers. Each new word gets a short definition, and more trips wait at Greece tours.
What does a Rethymno ATV tour mean?
A Rethymno ATV tour is an outing on a quad bike or a similar off-road vehicle. It takes place near the town of Rethymno on Crete, a Greek island. This section explains the vehicle types that sit behind the name.
A Rethymno ATV tour brings up the side-by-side, which is a type of light off-road vehicle. This vehicle has at least two seats inside a roll cage. A roll cage is a set of metal tubes that rings the seats. It also has at least four wheels or tracks, foot controls and a steering wheel.
The same vehicle is also called a UTV, an ROV or a MOHUV, depending on its use. UTV is short for utility terrain vehicle. Since the 2017 Dakar Rally, four-wheel side-by-sides with a 1000 cc engine limit have had a separate class. A cc is a cubic centimetre, a unit that sizes an engine.
A dune buggy is built for sand dunes, beaches and desert fun. Sandrails run from one-seat models with small engines to four-seat vehicles with eight or more cylinders. A cylinder is the chamber where a piston slides. Since early World War II, the UK Special Air Service has used cut-down, light off-road vehicles.
- Frame: A side-by-side has at least two seats and sits inside a roll cage.
- Name: A Rethymno ATV tour is a label for a ride on a quad or a side-by-side.
- Class: Four-wheel side-by-sides with a 1000 cc limit race in their own Dakar class.
The side-by-side and the dune buggy belong to one family of light off-road vehicles. A Rethymno ATV tour is a plain name for a ride in that family. The next sections cover the engine, the belt drive, fuel injection, the chain and the radiator.
On a Rethymno ATV tour, what does the four-stroke engine add?
A Rethymno ATV tour brings up the four-stroke engine. This is an internal combustion engine in which the piston completes four separate strokes. A stroke is one trip of the piston up or down its cylinder. This section follows the four strokes in order.
The first stroke is intake. It begins at top dead centre and ends at bottom dead centre. Dead centre marks where the piston turns round. As the piston falls, it draws a mix of air and fuel into the cylinder. A Rethymno ATV tour meets this stroke only as a name.
The second stroke is compression. The piston squeezes the mixture before ignition, and both valves stay shut. These are the intake valve and the exhaust valve. A valve is a small door that opens and shuts a port. In a gasoline engine, a spark plug then ignites the squeezed mixture.
The third stroke is the power stroke, which produces the work that turns the crankshaft. The crankshaft is a bent shaft. The fourth is the exhaust stroke, which pushes the spent mixture out through the exhaust port. In a diesel engine, the high compression itself makes the heat that ignites the fuel.
- Intake: A Rethymno ATV tour page covers intake, the stroke that fills the cylinder.
- Power: The power stroke produces the mechanical work that turns the crankshaft.
- Uses: Four-stroke engines run in cars, trucks, diesel trains, light aircraft and motorcycles.
An engine of this kind cycles through intake, compression, power and exhaust. The Daimler Reitwagen used a four-stroke engine. A Rethymno ATV tour is a page label here, and the engine is one of its topics. The next section looks at the belt drive.
On a Rethymno ATV tour, what does the continuously variable transmission add?
A Rethymno ATV tour brings up the continuously variable transmission, called a CVT. A CVT is an automatic transmission that can change through a continuous range of gear ratios. A gear ratio compares how fast two linked parts turn.
Other transmissions give a limited number of gear ratios in fixed steps. A CVT does not work in steps. With suitable control, it can let the engine run at a constant angular velocity. Angular velocity means how fast something spins. A Rethymno ATV tour meets this idea only as a name.
A pulley CVT changes its ratio by closing one pulley’s halves and opening the other’s. Each pulley in a V-belt CVT is made of two cone-shaped halves. A belt runs between the two pulleys. A belt-driven CVT design offers an efficiency of about 88%. Efficiency is the share of power that is not lost.
Toroidal CVTs withstand higher torque loads than pulley-based ones. Torque is a twisting force. Hydrostatic CVTs serve small and medium farm and earthmoving machines. In 1879 the American Milton Reeves invented a CVT for sawmilling. A sawmill cuts logs into boards. In 1958 a Dutch car became the first mass-production car with a CVT.
- Idea: A Rethymno ATV tour page notes that a CVT can change through a continuous range of gear ratios.
- Belt: Each pulley in a V-belt CVT is made of two cone-shaped halves.
- Start: Milton Reeves invented a CVT for use in sawmilling in 1879.
A CVT swaps fixed steps for a smooth range of ratios. A Rethymno ATV tour is a page label, and the transmission is one of its topics. Toroidal and hydrostatic types show other shapes of the idea. The next section turns to fuel injection.
On a Rethymno ATV tour, what does fuel injection add?
A Rethymno ATV tour brings up fuel injection, the introduction of fuel in an internal combustion engine. Fuel injection sprays pressurised fuel into the engine. Pressurised means that the fuel is pushed under force. A fuel pump is one device that can do this.
A device to pressurise the fuel is needed, such as a fuel pump. The injector then atomises the fuel through a small nozzle under high pressure. The nozzle is a narrow opening. To atomise is to break a liquid into a fine spray. A Rethymno ATV tour meets this method only as a name.
Since the 1980s, electronic systems have been used to control fuel metering. Recent systems use an electronic engine control unit. This unit meters the fuel and also controls the ignition timing. Metering means measuring out the right amount of fuel. Ignition timing is the moment the spark fires. A spark lights the mixture.
Single-point injection uses one injector in a throttle body on an intake manifold. A manifold is a branched air pipe. Multi-point injection puts fuel into the intake ports just upstream of each cylinder’s intake valve. In 1872 George Bailey Brayton patented an engine that used a pneumatic fuel injection system. Pneumatic means driven by air.
- Spray: A Rethymno ATV tour page notes that fuel injection sprays pressurised fuel through a small nozzle.
- Control: An electronic engine control unit meters the fuel and controls ignition timing.
- Types: Single-point injection uses one injector, while multi-point injection serves the intake port of every cylinder.
Fuel injection is a way to spray fuel into an engine under pressure. A Rethymno ATV tour is a page label, and the method is one of its topics. Electronic control shaped the method. The next section looks at the chain drive.
On a Rethymno ATV tour, what does the chain drive add?
A Rethymno ATV tour brings up the chain drive. This is a way of sending mechanical power from one place to another. A roller chain passes over a toothed wheel called a sprocket. This section follows how the links and the teeth mesh.
A roller chain passes over a sprocket, and the sprocket’s teeth mesh with the chain’s links. To mesh is to fit together. A drive chain can go around corners when more than two gears sit along it. A Rethymno ATV tour meets this part only as a name.
Gears that neither put power in nor take it out are called idler wheels. Varying the diameter of the input and output gears changes the gear ratio. Diameter is the width of a circle through its centre. Duplex chains are two chains joined side by side, which allows more power and torque.
Chain drive set the 1885 safety bicycle apart from the penny-farthing. The chain-driven safety bicycle led to the end of the penny-farthing. The Greek engineer Philon of Byzantium described the Polybolos, the oldest known chain drive application. Su Song used a chain drive to operate an armillary sphere in his clock tower.
- Parts: A Rethymno ATV tour page notes that a roller chain passes over a sprocket with meshing teeth.
- Ratio: Varying the diameter of the input and output gears changes the gear ratio.
- Bicycle: Chain drive set the 1885 safety bicycle apart from the penny-farthing.
A chain drive links two wheels with a loop of metal links. An armillary sphere is a model of the sky made of rings. A Rethymno ATV tour is a page label, and the chain is one of its topics. Next comes the radiator.
On a Rethymno ATV tour, what does the radiator add?
A Rethymno ATV tour brings up the radiator, a heat exchanger that cools internal combustion engines. The radiator moves heat from the coolant into the air that passes through it. Coolant is the liquid that carries heat away from the engine.
Early radiators used downward vertical flow, driven by a thermosyphon effect. A thermosyphon moves a liquid by the rise of warm liquid and the fall of cool liquid. A small radiator called the heater core warms the cabin interior, not the engine. A Rethymno ATV tour meets these parts only as names.
Modern car engine temperature is mainly controlled by a wax-pellet thermostat. The thermostat opens when the coolant reaches its activation temperature, which lets water reach the radiator. The coolant is kept above atmospheric pressure to raise its boiling point. Cooling system pressure runs from 4 to 30 psi, which means pounds per square inch.
The automobile water radiator is attributed to Karl Benz. Honeycomb radiators used round tubes swaged into hexagons at their ends. To swage is to press metal into a new shape. Electric cars also use coolant, pumps and radiators to cool batteries and motors. So the radiator is not tied to petrol.
- Job: A Rethymno ATV tour page notes that a radiator moves heat from the coolant into the air.
- Control: A wax-pellet thermostat opens when the coolant reaches its activation temperature.
- Maker: The automobile water radiator is attributed to Karl Benz.
A radiator keeps an engine cool by passing heat from liquid to air. A Rethymno ATV tour is a page label, and the radiator is one of its topics. Coolant, thermostat and pressure work together. The next and last section answers four short questions.
What four questions does a Rethymno ATV tour raise?
A Rethymno ATV tour raises four short questions, and each has a plain answer below. They cover the weather of Greece, the town of Rethymno, the Libyan Sea and the Mediterranean carob tree. Each answer rests on its own source facts.
Which season suits a Rethymno ATV tour?
Greece shows wide weather extremes. The highest yearly rainfall, 2529 mm, is recorded in Theodoriana. The lowest temperature ever recorded in the country, −27.8 °C, was in Ptolemaida. Mount Olympus, at 2,918 metres, is the highest peak in Greece. A mm is a millimetre.
Which town lies behind a Rethymno ATV tour?
Rethymno is the town on Crete. Venetian rulers set up a trading station there between Heraklion and Chania. Almost all of the old town came from Venetian builders. The University of Crete has a campus in Rethymno, which also holds the University Library.
Which sea lies on the far shore of the island behind a Rethymno ATV tour?
Part of the Mediterranean Sea off the African coast of ancient Libya is called the Libyan Sea. The south coast of Crete, which borders it, includes the Asterousia Mountains as well as the Mesara Plain. The islands of this sea, besides Crete, are Gavdos, Gavdopoula, Koufonisi and Chrysi.
Which Mediterranean tree is worth knowing before a Rethymno ATV tour?
The home range of carob trees spans the Mediterranean basin and the Middle East. A carob grows up to 15 metres tall. Its pods take a full year to develop and ripen. It is an evergreen tree. A pod is the long case that holds the seeds of a plant.