A newbie question plus i'm a girl so take it easy:p ,
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??
A newbie question plus i'm a girl so take it easy:p ,
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??
You can do all the changes you mention without retuning.
One thing to consider is the "age" of the cassettes. If your older one is worn it has mated itself to your chain and a new cassette could have issues with a stretched chain. Best way is to give it a shot and see how she runs. Tools are cheap; lockring socket and chain whip total less than $20.
