A newbie question plus i'm a girl so take it easy ,
I've a 12-25 on a 39x53 so once my bikes all set up with this gearing and tuned in if I did decide to remove the 9 spd 12-25 cassette and fit for example (although I won't) a 9 spd 11-21 cassette and replace the wheel back on my bike would the gears need retuning or will the lesser teeth not affect the rear derailler?? And would it be the same if i'd had a 11-21 and then changed it to a 12-25 would the extra teeth cause shifting problems resulting in retuning needing to be done?? So what i'm saying is if you swap different 9 spd cassette combinations will the bike need to be retuned each change??
I've a 12-25 on a 39x53 so once my bikes all set up with this gearing and tuned in if I did decide to remove the 9 spd 12-25 cassette and fit for example (although I won't) a 9 spd 11-21 cassette and replace the wheel back on my bike would the gears need retuning or will the lesser teeth not affect the rear derailler?? And would it be the same if i'd had a 11-21 and then changed it to a 12-25 would the extra teeth cause shifting problems resulting in retuning needing to be done?? So what i'm saying is if you swap different 9 spd cassette combinations will the bike need to be retuned each change??