Return to Answer

For Internal Gearing
Internal or hub gears can be expressed as a ratio of how many times the rear wheel turns for each time the crank rotates once. The ratio is determined by the number of teeth on the sprocket (the term for the gear on the back of a single speed or hub geared bicycle), the number of teeth on the chainring and the way the hub is designed to work for each speed.

For example, a bike with a 50 tooth chainring and a 30 tooth sprocket using a bendix 2 speed red band would have a low range of 2.3 and a high range of 3.4. The rear wheels spins 2.3 times in the low gear for every rotation of the crank and 3.4 times in the high gear for every rotation of the crank.

Sheldon Brown has a calculator with a wide range of options for calculating ratios.
For a visual reference:
From www.cyclinguk.org
The chart assumes the sprocket and chainring is a 1 to 1 ratio.

For External Gearing

Here is some common terminology so that we can zero in on the words you need.

Based on the contents of the question I'm assuming an external gear system so focusing on that.
This is just the basics of gear ratios. I'm not going to get into crank length and wheel size. Sheldon Brown has a detailed article on gear ratios with a nice chart.

Cassette: The cassette is a stack of cogs. Most bikes will have 5 to 11 cogs. Each cog has a number of teeth.

Chainrings: A bike will have 1 to 3 chainrings. Each chainring has teeth

Gear ratio describes the relationship between the number of teeth on the chainrings and the cogs. if the chainring has 50 teeth and the chain is on the cog with 11 teeth then 50/11= 4.55 so, for every revolution of the pedals the rear wheel will turn 4.55 times. This gear would take more force to turn than a gear ratio of .5 which would require very little force but give very little forward motion. A gear ration of .5 would be good for climbing steep hills.

A high gear gives you more revolutions of the rear wheel per revolution of the pedals than a low gear.

Back to the question

On my old bike the first gear was easier to pedal than my current first gear and the 21st gear was harder to pedal than my current 8th gear.

On your old bike first gear had a lower gear ratio than your current bike and the 21st gear was a higher gear ratio than your current 8th gear.
If you knew the number of teeth for the different gears you could describe exactly how much difference there is between the bikes.

For Internal Gearing
Internal or hub gears can be expressed as a ratio of how many times the rear wheel turns for each time the crank rotates once. The ratio is determined by the number of teeth on the sprocket (the term for the gear on the back of a single speed or hub geared bicycle), the number of teeth on the chainring and the way the hub is designed to work for each speed.

For example, a bike with a 50 tooth chainring and a 30 tooth sprocket using a bendix 2 speed red band would have a low gear of 2.3 and a high gear of 3.4. The rear wheels spins 2.3 times in the low gear for every rotation of the crank and 3.4 times in the high gear for every rotation of the crank.

Sheldon Brown has a calculator with a wide range of options for calculating ratios.
For a visual reference:
From www.cyclinguk.org
The chart assumes the sprocket and chainring is a 1 to 1 ratio.

For External Gearing

Here is some common terminology so that we can zero in on the words you need.

Based on the contents of the question I'm assuming an external gear system so focusing on that.
This is just the basics of gear ratios. I'm not going to get into crank length and wheel size. Sheldon Brown has a detailed article on gear ratios with a nice chart.

Cassette: The cassette is a stack of cogs. Most bikes will have 5 to 11 cogs. Each cog has a number of teeth.

Chainrings: A bike will have 1 to 3 chainrings. Each chainring has teeth

Gear ratio describes the relationship between the number of teeth on the chainrings and the cogs. if the chainring has 50 teeth and the chain is on the cog with 11 teeth then 50/11= 4.55 so, for every revolution of the pedals the rear wheel will turn 4.55 times. This gear would take more force to turn than a gear ratio of .5 which would require very little force but give very little forward motion. A gear ration of .5 would be good for climbing steep hills.

A high gear gives you more revolutions of the rear wheel per revolution of the pedals than a low gear.

Back to the question

On my old bike the first gear was easier to pedal than my current first gear and the 21st gear was harder to pedal than my current 8th gear.

On your old bike first gear had a lower gear ratio than your current bike and the 21st gear was a higher gear ratio than your current 8th gear.
If you knew the ratios for the different gears you could describe exactly how much difference there is between the bikes.

NOTE: The question was updated to clarify that the question refers to an internal gear system. Adding information to cover the question, leaving the original answer.

Internal or hub gears can be expressed as a ratio of how many times the rear wheel turns for each time the crank rotates once. The ratio is determined by the number of teeth on the sprocket (the term for the gear on the back of a single speed or hub geared bicycle), the number of teeth on the chainring and the way the hub is designed to work for each speed.

For example, a bike with a 50 tooth chainring and a 30 tooth sprocket using a bendix 2 speed red band would have a low range of 2.3 and a high range of 3.4. The rear wheels spins 2.3 times in the low gear for every rotation of the crank and 3.4 times in the high gear for every rotation of the crank.

Sheldon Brown has a calculator with a wide range of options for calculating ratios.
For a visual reference:
From www.cyclinguk.org
The chart assumes the sprocket and chainring is a 1 to 1 ratio.

Start original answer:

Here is some common terminology so that we can zero in on the words you need.

Based on the contents of the question I'm assuming an external gear system so focusing on that.
This is just the basics of gear ratios. I'm not going to get into crank length and wheel size. Sheldon Brown has a detailed article on gear ratios with a nice chart.

Cassette: The cassette is a stack of cogs. Most bikes will have 5 to 11 cogs. Each cog has a number of teeth.

Chainrings: A bike will have 1 to 3 chainrings. Each chainring has teeth

Gear ratio describes the relationship between the number of teeth on the chainrings and the cogs. if the chainring has 50 teeth and the chain is on the cog with 11 teeth then 50/11= 4.55 so, for every revolution of the pedals the rear wheel will turn 4.55 times. This gear would take more force to turn than a gear ratio of .5 which would require very little force but give very little forward motion. A gear ration of .5 would be good for climbing steep hills.

A high gear gives you more revolutions of the rear wheel per revolution of the pedals than a low gear.

Back to the question

On my old bike the first gear was easier to pedal than my current first gear and the 21st gear was harder to pedal than my current 8th gear.

On your old bike first gear had a lower gear ratio than your current bike and the 21st gear was a higher gear ratio than your current 8th gear.
If you knew the number of teeth for the different gears you could describe exactly how much difference there is between the bikes.

For Internal Gearing
Internal or hub gears can be expressed as a ratio of how many times the rear wheel turns for each time the crank rotates once. The ratio is determined by the number of teeth on the sprocket (the term for the gear on the back of a single speed or hub geared bicycle), the number of teeth on the chainring and the way the hub is designed to work for each speed.

For example, a bike with a 50 tooth chainring and a 30 tooth sprocket using a bendix 2 speed red band would have a low range of 2.3 and a high range of 3.4. The rear wheels spins 2.3 times in the low gear for every rotation of the crank and 3.4 times in the high gear for every rotation of the crank.

Sheldon Brown has a calculator with a wide range of options for calculating ratios.
For a visual reference:
From www.cyclinguk.org
The chart assumes the sprocket and chainring is a 1 to 1 ratio.

For External Gearing

Here is some common terminology so that we can zero in on the words you need.

Based on the contents of the question I'm assuming an external gear system so focusing on that.
This is just the basics of gear ratios. I'm not going to get into crank length and wheel size. Sheldon Brown has a detailed article on gear ratios with a nice chart.

Cassette: The cassette is a stack of cogs. Most bikes will have 5 to 11 cogs. Each cog has a number of teeth.

Chainrings: A bike will have 1 to 3 chainrings. Each chainring has teeth

Gear ratio describes the relationship between the number of teeth on the chainrings and the cogs. if the chainring has 50 teeth and the chain is on the cog with 11 teeth then 50/11= 4.55 so, for every revolution of the pedals the rear wheel will turn 4.55 times. This gear would take more force to turn than a gear ratio of .5 which would require very little force but give very little forward motion. A gear ration of .5 would be good for climbing steep hills.

A high gear gives you more revolutions of the rear wheel per revolution of the pedals than a low gear.

Back to the question

On my old bike the first gear was easier to pedal than my current first gear and the 21st gear was harder to pedal than my current 8th gear.

On your old bike first gear had a lower gear ratio than your current bike and the 21st gear was a higher gear ratio than your current 8th gear.
If you knew the number of teeth for the different gears you could describe exactly how much difference there is between the bikes.

Here is some common terminology so that we can zero in on the words you need.

Based on the contents of the question I'm assuming an external gear system so focusing on that.
This is just the basics of gear ratios. I'm not going to get into crank length and wheel size. Sheldon Brown has a detailed article on gear ratios with a nice chart.

Cassette: The cassette is a stack of cogs. Most bikes will have 5 to 11 cogs. Each cog has a number of teeth.

Chainrings: A bike will have 1 to 3 chainrings. Each chainring has teeth

Gear ratio describes the relationship between the number of teeth on the chainrings and the cogs. if the chainring has 50 teeth and the chain is on the cog with 11 teeth then 50/11= 4.55 so, for every revolution of the pedals the rear wheel will turn 4.55 times. This gear would take more force to turn than a gear ratio of .5 which would require very little force but give very little forward motion. A gear ration of .5 would be good for climbing steep hills.

A high gear gives you more revolutions of the rear wheel per revolution of the pedals than a low gear.

Back to the question

On my old bike the first gear was easier to pedal than my current first gear and the 21st gear was harder to pedal than my current 8th gear.

On your old bike first gear had a lower gear ratio than your current bike and the 21st gear was a higher gear ratio than your current 8th gear.
If you knew the number of teeth for the different gears you could describe exactly how much difference there is between the bikes.

NOTE: The question was updated to clarify that the question refers to an internal gear system. Adding information to cover the question, leaving the original answer.

Internal or hub gears can be expressed as a ratio of how many times the rear wheel turns for each time the crank rotates once. The ratio is determined by the number of teeth on the sprocket (the term for the gear on the back of a single speed or hub geared bicycle), the number of teeth on the chainring and the way the hub is designed to work for each speed.

For example, a bike with a 50 tooth chainring and a 30 tooth sprocket using a bendix 2 speed red band would have a low range of 2.3 and a high range of 3.4. The rear wheels spins 2.3 times in the low gear for every rotation of the crank and 3.4 times in the high gear for every rotation of the crank.

Sheldon Brown has a calculator with a wide range of options for calculating ratios.
For a visual reference:
From www.cyclinguk.org
The chart assumes the sprocket and chainring is a 1 to 1 ratio.

Start original answer:

Here is some common terminology so that we can zero in on the words you need.

Based on the contents of the question I'm assuming an external gear system so focusing on that.
This is just the basics of gear ratios. I'm not going to get into crank length and wheel size. Sheldon Brown has a detailed article on gear ratios with a nice chart.

Cassette: The cassette is a stack of cogs. Most bikes will have 5 to 11 cogs. Each cog has a number of teeth.

Chainrings: A bike will have 1 to 3 chainrings. Each chainring has teeth

Gear ratio describes the relationship between the number of teeth on the chainrings and the cogs. if the chainring has 50 teeth and the chain is on the cog with 11 teeth then 50/11= 4.55 so, for every revolution of the pedals the rear wheel will turn 4.55 times. This gear would take more force to turn than a gear ratio of .5 which would require very little force but give very little forward motion. A gear ration of .5 would be good for climbing steep hills.

A high gear gives you more revolutions of the rear wheel per revolution of the pedals than a low gear.

Back to the question

On my old bike the first gear was easier to pedal than my current first gear and the 21st gear was harder to pedal than my current 8th gear.

On your old bike first gear had a lower gear ratio than your current bike and the 21st gear was a higher gear ratio than your current 8th gear.
If you knew the number of teeth for the different gears you could describe exactly how much difference there is between the bikes.