using the sheldon brown one, I save screenshots of the chart that gets made from putting in a specific bike info, so I have a reference for a bike.
Here is my Kuw after I changed the granny to a 24, so 50/40/24 with a 13-30 7 spd cassette and 700x28 wheels and tires
and then my more recent heavy touring bike, 44/32/22, with a 11-34 9 speed cassette and 26x2in wheels and tires (for some reason, couldnt attach this bikes chart...no matter, you get the picture)
the % numbers you see on the charts is the % jump between each gear, which is nice to know and useful if you start to be attentive to this stuff and figure out how sometimes on older bikes, the % jumps were kinda big--which in real life is where its hard to find in some given conditions one gear is too low and the next one is too high....more modern bkes with more speeds tend to have smaller jumps than back in the day, or at least manageable jumps but with a much much wider range of gears, ie cassettes of 11-42 for example.
