How do you calculate gear ratios?

[philinmerthyr]

How do you calculate if one gear ratio. Is easier than another?

Fr example is a 34 front and 34 rear combination easier to pedal than a 30 front and 25 rear combination?

Is there a simple formula to use to calculate this?

 

[Rohloff_Brompton_Rider]

http://xldev.co.uk/bgc.html

Untick the Brompton specific box.

 

[ohnovino]

Front divided by back. Bigger result = harder/faster gear.

e.g. 34/34 = 1, 30/25 = 1.2, so the 34 front and 34 rear combo would be easier.

 

[slowmotion]

Here's another gear inch calculator
http://cycleseven.org/bicycle-gear-inch-calculator
The smaller the number of gear inches, the "easier" the gear. Gear inches are quite handy if you want to compare different ratios with different wheel sizes.

 

[SpokeyDokey]

http://www.bikecalc.com/gear_ratios

 

[deptfordmarmoset]

I think in terms of ratios à la ohnovino and SpokeyDokey. Some people prefer to use gear inches, so if they start giving their figures it doesn't really help ratio users relate to them. If I remember correctly, Sheldon Brown has both a ratio and gear inch calculator.

 

[Rohloff_Brompton_Rider]

The one I referenced has Gear Inches, Metres Development, Speed MPH and KPH.

 

[Nigelnaturist]

Front divided by back. Bigger result = harder/faster gear.

e.g. 34/34 = 1, 30/25 = 1.2, so the 34 front and 34 rear combo would be easier.

It's only faster if the cadence stays the same.

 

[guitarpete247]

Gear inches (or metric) show the size of wheel you would be pedalling on a penny farthing (ordinary). So the bigger gear inches the harder to turn but the faster you travel.