What is a compact crank on a bike?

A compact crank refers to a road bike crankset with relatively smaller chainrings that can make pedaling easier. While ‘standard’ cranks come with a 53-tooth large chainring and a 39-tooth small ring, compact cranks usually feature 50- and 34-tooth rings.

In respect to this, what is a Cotterless crank arm?

The bottom bracket spindle (axle) used with a standard cotterless crank has tapered square ends, which fit into matching tapered square holes in the cranks. The ends of the axle are threaded, either male or female, and a bolt or nut (called the “fixing” bolt/nut) pulls the crank tightly onto the end of the axle.

What length crank arms should I use?

Crank Arm LengthsHeightCrank Length(cm)5’11” (1803mm)175mm5’10” (1778mm)172.5mm5’9″(1753mm)170mm5’7″ (1702mm)165mm

What is correct crank length?

Whereas now 170 is ‘short’ 172.5mm is ‘normal’ and 175 mm cranks are very common. Still though, the difference between 170 mm and 175mm is less than 3% and leg lengths of bike riders vary by far more than that.

What is a compact group set?

this limits how small an inside ring you can fix on there, which on a standard chainset is a 39 tooth ring. but this may not be small enough for steep hills. a compact crankset has a smaller diameter bolt hole radius (pcd pitch circle diameter) of 110mm enabling you to put say a 34tooth chain ring on there.

What is the cassette on a bike?

A bicycle cassette is the cluster of sprockets located on the rear hub of your bike, slotting onto a freehub body and held firmly in place with a threaded cassette lockring.

What is the chainset on a bike?

A chainset is part of the drivetrain on a bike. It connects via the chain (or belt in some cases) to the drive wheel of the bike. The chainset rotates using the bottom bracket as a support and housing. When the chainset travels in a clockwise direction, this provides the power to move the bike forwards.

What is a chainring?

It consists of one or more sprockets, also called chainrings or chainwheels attached to the cranks, arms, or crankarms to which the pedals attach. It is connected to the rider by the pedals, to the bicycle frame by the bottom bracket, and to the rear sprocket, cassette or freewheel via the chain.

What is a BB on a bike?

The bottom bracket on a bicycle connects the crankset (chainset) to the bicycle and allows the crankset to rotate freely. It contains a spindle that the crankset attaches to, and the bearings that allow the spindle and cranks to rotate. An old American term for bottom bracket is hanger.

What is the top gear on a bike?

A high gear, sometimes referred to by cyclists as a ‘big gear’, is optimal when descending or riding at high speeds. The highest, or biggest gear on a bicycle is achieved by combining the largest front chainring size with the smallest rear cog or sprocket — expressed as ’53×11′, for example.

Which bike gear is the hardest?

High Gear = Hard = Good for Descending: The “highest” gear on your bike is the largest chain ring in the front and the smallest cog on your cassette (rear gears). In this position, the pedaling will be the hardest and you’ll be able to accelerate while traveling downhill.

Is it better to have a higher or lower gear ratio?

The lower the number, the faster the car will go with the same number of engine revolutions. The higher the number the better the car will accelerate, but at the expense of high speed cruising. Now for the confusing part of the story. A high numerical gear ratio is called a low gear or low rear end, and vice versa.

What does a 4 11 gear ratio mean?

In simple terms, the numbers mean how many turns of the drive shaft to one turn of the rear wheel. If you are cruising down the freeway at 60 MPH with 3.00 gears, in a typical high gear with a 1:1 output ratio, it simply means that the drive shaft (engine) is spinning 3 times for every 1 rotation of your tire.

Why is there more torque in lower gear?

The greater rate of rpm increase versus road speed provides greater acceleration. Since horsepower increases as engine rpm increases (up to the point when the torque curve drops off at a greater rate than engine rpm increase), the engine is able to overcome loads more easily with lower gears than with higher gears.

What does more torque do?

Horsepower is the total power output of an engine, while torque measures the “turning/torquing ability” of the engine. Practically, torque is a better measurement of how quickly your car will accelerate, while horsepower (relative to weight) is a better measure of your car’s top speed.

What happens to torque when you increase speed?

Torque can be understood to be the effort behind the work done and angular speed specifies the rate at which it happens. If the input power is constant, torque and angular speed become inversely proportional. Only then does the angular speed decreases as the torque increases.

Why does torque decrease as RPM increase?

After this point in the RPM band, the torque reduces due to the air flow losses in the valves and mechanical losses which dominate at higher speeds. These factors reduce the volumetric efficiency and thereby the torque. However, the power continues to increase as it is a product of speed and torque.

Is torque directly proportional to speed?

The Reason that Torque and Speed are said to be inversely proportional is the ability to generate torque diminishes with increase speed. The reason for this is because the BackEMF opposes the supply that is attempting to force current into the stator, that will generate EM-Torque.

How speed and torque are related?

The relation between the torque of vehicle and speed is Power = Torque x Speed. So as the speed increases, the torque decreases. The torque and power produced by the engine is varied in following manner: As you can see, the maximum torque is obtained at around 50% of the engine speed.

Is motor torque proportional to current?

Relation between motor’s torque/speed and its voltage/current. The torque of a motor is proportional to the current flowing through it ( τ ∝ i ). The angular velocity of a motor is proportional to the voltage across it ( ω ∝ v ).

What is the standard crank arm length?

Whereas now 170 is ‘short’ 172.5mm is ‘normal’ and 175 mm cranks are very common. Still though, the difference between 170 mm and 175mm is less than 3% and leg lengths of bike riders vary by far more than that.

How do you know what size bottom bracket to get?

The 68mm and 73mm dimension measure the width of the bottom bracket on the frame of the bike with no BB installed, simply the width of the shell. Most road bikes that use a threaded bottom bracket measure 68mm wide and most cross country/trail mountain bikes measure 73mm.

What cranks fit bb92?

The BB92 standard, also known as Shimano Press Fit, uses a bearing housed in a nylon or aluminum cup that is pressed into a bottom bracket shell that measures 92mm wide. This standard is designed around the 24mm spindle diameter used by Shimano.

What is a Shimano press fit bottom bracket?

The bearings have no plastic retainer or cups. These bearings are a mild press fit into the bottom bracket shell. The cartridge bearing are 37mm outside diameter and 24mm inside diameter to accept the Shimano® Hollowtech® II cranksets.

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