Leif-fire-eater

Hello,

Trying to get a grasp on gear ratios and need somewhere to start. I'm currently riding a 48x16 and it feels good. I have a new bike with a 44 tooth chainring and was wondering what size cog I should use to keep a similar ratio. Any help would be great.

soyboy

14 or 15

mattface 

Use Sheldon brown's handy dandy Gear calculator to see how many gear inches your current combo is, and compare it to the 44 tooth possibilities

https://sheldonbrown.com/gears/

Leif-fire-eater

Ok next stupid question. what is the gain ratio?

mattface 

https://sheldonbrown.com/gain.html

Leif-fire-eater

Ok I'm seeing that I need to dig in much deeper to sheldon browns site, before I keep asking more easy questions. Thanks for the help

pklove

You also need to keep in mind the number of skid spots you will have. Seeing as 44x14 and 44x16 only have 7 and 8 spots, respectively, on the wheel where you will skid at, you are kinda sandwiched into 44x15 if you care about that sort of thing. 44x15 has 15 skid spots.

Leif-fire-eater

hmmm? how does this work, right now, I just lock up whereever and throw a skid.

pklove

I attached a spreadsheet I made and you can look at the formulas if you want. But basically, every gear has a number of points at which you skid. An awesome gear ratio will have 2x the number of your cog points at which you skid on your wheel. A tiny bit less awesome ratio will have 1x the number of your cog. Bad ones will have less. I started on a ratio with 5 skid spots and sailed through tires.

My spreadsheet assumes you are ambidextrious with skidding. If you aren't, then you would prefer a odd number of skid spots so they cycle back and forth from left side front skid spots to right side front skid spots.

Sorry if this is too nerdy.