Are gear inche all the same?

It there any difference in a gear inch of 87 for example by using a 42 X 13 or a 52 X 16. Both give a bit over 87 but does the larger chain ring have an influence?

nothing you’ll notice.

What Pip said.

Some folks reckon chains last longer on bigger sprockets and see the late, great Sheldon on even tooth count sprockets (not sure if this has been mis-indexed and should be on his bicycle humour page).

Are you really a Magican?

skid patches… 13 vs 4. Good vs bad.

Either way, 87 GI is pretty big if you are riding street.

are you converting a road bike and wondering which chainring to keep?

i think other than skid patches, and aesthetics (a larger chainring might make your street bike look more like a real track bike) another factor to consider is what changes you might want to make to the ratio later on.

ie: if you run a big 52t on the front, you’re going to need a huge cog on the back if you ever want a low ratio for a day or a week (say for polo or tricks). Sprockets bigger than 17t aren’t so common.

it’s always handy to be able to change your sprocket one size up or down, and get a gear that will be useful for you (skid patches included).

also don’t forget that changing the total number of teeth by more than about 4 will mean changing the length of your chain, which is probably why mid-range chainrings (44-49t) are more popular off the track.

sprockets above 17t are plenty common. Surly and Phil Wood both make them.

  • Joel

I think what was meant is that there is more variety of sprockets in lower tooth counts. Agreed that the Surly, Phil Wood, Soma and Roselli brands all do large cogs, but it seems that every man and his dog makes a 15T cog.

yeh, i’ve somehow ended up with 3x15t and 1x14t that i don’t reckon i’ll ever use.

Another thought on this - smaller chainring plus bigger cog means if you do want to gear up or down a sprocket the gear-inch increments/decrements aren’t so big.