is switching from a 18t to a 17t really going to do much?
 

hey, I am setting up for this long pancake flat ride and I dont feel like spinning my legs of with a 49-18. Would changing to a 17t cog not change the gearing enough to notice or should I switch to a 16t instead

1 tooth change is generally a lot more significant of a change than one would think.

I ride 49x17 and love it, for whatever that's worth.

1 tooth in the back equals 3 in the front

Its a 5.6% difference.

That's the most correct answer that could be given. Thank you. Toast.

Go here:

http://sheldonbrown.com/gears/

Enter your correct tire size and crank length, and choose Gear Inches.

Put in a couple of different chainring sizes and a bunch of cog sizes (cassette) and click on calculate.

Study the results.

It's like shifting one gear on your road bike. More or less.

From 46x17 to 46x18 I felt a really big difference. You'd be surprised.

I just recently switched from 46x18 (which was horrible for me, riding in the city I wasn't even able to keep up with the cars) to 46x16 which is pretty perrfect. It was a bit of a difference though.

put on the 14t i've offered you before. its only 100 miles! jeez.

and while you're at it, bump up that chanring to a 67. 67x14 will rock hard.

(no really though, i have a 14t and a 15t if you wanna take them for a ride around the city, just PM me, that way you can feel the difference a little)

It's a definite difference, remember that smaller adjustments are made by changing chainring size, larger ones by changing cogs.

The smaller your chainring the more difference you'll notice when you go up or down a tooth on the cog. 42x18 vs. 42x17 = big difference. 49x18 vs. 49x17 = not as much difference.

49x18 sounds pretty good for the street. 49x16 seems a little tall unless it's dead flat.

crank length dosnt make a difference in gear inches, you only need to calculate crank length with your for your gain ratio. I mean DUHHHHHHHHHHHHHHHHHHHH.

The bigger the chainring, the more noticable the difference.......so yes, you will definitely feel the diff.

I made the exact switch about a week ago, and I definately notice the bigger gear. I don't have a speedometer, so I don't know if my speed has changed, but with a 49X18 I had a nice easy spin most of the time, and now I feel like I'm pushing the gear more as opposed to spinning. For a flat route 49X17 could be fine.