i recently changed over to a compact crank, 50/34, from a triple, 52/42/30.
i have a 10 speed rear cassette 12-27. all of the drive train consists of 105 components. i do most of my riding in the 16-17-19 gears on the rear cassette. i use the 12-13 gears almost never.
it would be nice to have a 18tooth gear between the 17-19. i figure remove the 13 gear and replace it with a 18.
can you buy just a 18 tooth gear? or will i have to buy a complete cassette with a 18 in it?
in my research the only way to get a 18 in a 10 speed cassette is with ultegra or dura ace. they are both expensive. i would assume i could find a 18 tooth gear in a 9 speed and save a few bucks. i would assume the gear thickness between a 9 and 10 would be the same. the spacers between the gears would be different. an i wrong on this assumption?
i would remove the 13 instead of the 12 because the 12 is designed to mate with the lock ring. do they make a 13 lock ring gear?
i am probably sure if i switched to the 34 ring in the front i could find similar gears but switching rings and rear gears gets complicated and i would assume would lead to cross chaining.
your input would be appreciated on solving this problem.