elbunta

If someone could give me a little advice would much appreciate it. I am a serious amateur rider. I am looking to get some new wheels and at the same time potentially a more easy going sprocket for big hill climbing. I am currently running CENTAUR 10spd with 11-23 on the rear and 39/53 on the front.
If I go to a 12-25 or 13-26 do I need a new chain too? If I get a new chain to go with the new wheel/sprocket does it simply interchange without needing to adjust the front derailleur. Is there anything I am missing?? Thanks.

Grasschopper

Hmm How many questions are in there?

Chain length will determine if you need a new one if the current one isn't worn. Of note here is that many 10s chains only get 1500-2500 miles of use before they wear so check the chain...you may need a new one anyway.

I can't see why you would need to adjust the FD due to a different cassette. New chain will have to be shortened to the proper length (they come long). You will want to check your RD setup to make sure you don't need limits or B screw adjustment (larger cogs may require B screw adjustment if the RD is now too close to the cogs).

Is there a wheel question in there somewhere?

biker7

Yeah...you need a longer chain with additional links that correspond to the number of cog teeth you increase in back...but could probably get by if you never shift into 53-26 which you shouldn't but chain lengths are generally spec'ed from the factory for all possible chainlines You have many options for Campy compatible chains and can find one for about $30 or so + shipping....I just picked up a KMC X10 to replace my KMC X10 that came on my Campy 10sp bike....been a good chain and the KMC missing link masterlink is strong...but not recommended to be reused which is fine with me.
As far as rear derailleur adjustment...only adjustment will be your upper cage pivot spring tension which controls vertical position of the cage relative to your largest cog.
Check out Campy's site for adjustment....see where you are in your travel right now with 23 tooth cog. Many that own Campy bikes have no idea what this adjustment is and it affects chain wrap and shifting quality to a degree. Other thing is you need to establish if you are running a short or medium cage Campy RD. You may be on the brink of acceptablility if running a std. double in front with short cage in back with a 26t rear cassette...may get some interference if you can't adjust the cage low enough to clear the largest 26t cog O.D. with top of cage when in 39-26.
HTH,
George

elbunta

thanks grasschopper and biker7. I now know a good deal less than I knew before I posted the thread!