STEVO820

my favorite gearing on road bikes is 42-12. its a nice solid gearing imo. i can hit 30+ on the flats and still crank up hills. i want my track bike to be about the same. the track bike is a 48-16. how do you figure out how close they are?

sorry if i sound ********

-Steve

also. what would my rear cog have to be at if i was in the big ring 53 it be comprable to the 42-12? does anyone have like a chart to figure this stuff out?

badkarma

Well, in a 42/12, you have a 3.5 gear ratio. In a 48/16 is 3.0

If you wanted comparable gearing to a 42/12 in a 53, you'd need either a 15 or 16 cog.

acape

Divide the numbers.

42/12 is a ratio of 3.5 (42 divided by 12)
48/16 is a ratio of 3 (48 divided by 16)

The closest gear combo with the 53 ring would be 53/15, with a ratio of 3.53.

Retro Grouch 

48-14 will come pretty close although a bit easier than 42-12. 53-15 will be close although a bit harder than 42-12.

acape

But I doubt either of these differences would be noticeable, in reality. They are very close.

STEVO820

ok i get you. so a 48-14 would be a 3.42 so it would be just about the same with a little extra kick. i thought their was more to it than that. like i said im ********. so i should look into a 14T cog.

MichaelW

Gear inches are the std method of comparison. This allows you to compare bikes with diferent size wheels. The exact meaning of a gear inch in archaic but it is a nice useful number.

Hammertoe

https://www.panix.com/~jbarrm/cycal/cycal.30f.html

Edit....Hows that for 4 posts at the same time. I find the above site a little easier to use than Sheldons'. Nothing against Sheldon....

STEVO820

yeah i was going to say. i know that the tenths make a difference but does the hundreds?