[Ghost234]

I am currently running a 12-25 and wish to switch to an 11-23 for an upcoming race. I am aware of the big ring to big ring plus 2 links in sizing the cassette, but do I add in the chain link (connector) once I have that distance figured out? Or is the plus two links including the link?


Also should I have to adjust my RDR as a result of this change, or should it be fine?

 

[Ventruck]

Do you plan going to the 12-25 right after? Because adjusting chain lengths over and over would be time-consuming, and considering the amount of time spent in the end gears, it (one or two links) won't make all the difference. The RD should be able to take up whatever slack upon the cassette change.

As for adjustments, maybe, maybe not. I went from an Ultegra 6600 12-25 to a Rival/Force OG-1070 12-26 without any adjustments needed.

 

[Kerry Irons]

No change

I am currently running a 12-25 and wish to switch to an 11-23 for an upcoming race. I am aware of the big ring to big ring plus 2 links in sizing the cassette, but do I add in the chain link (connector) once I have that distance figured out? Or is the plus two links including the link?

Also should I have to adjust my RDR as a result of this change, or should it be fine?

A change of 2 teeth does not warrant a change in chain length. Only one of those teeth are engaged by the chain (it wraps around half of the cog) and you can't remove a half link from the chain.

The best way to size a chain is using the small-small method, and so that doesn't care what the largest cog is as long as it is within the specification range of the derailleur.

Probably no adjustment of the rear derailleur will be required.

 

[cxwrench]

if you're changing cassettes and using the same wheel, just check it to make sure, but you prob won't need to do anything. i swap between 11/23, 25, 26 and 28 all the time and no chain length adjustment is ever necessary.

 

[vandalbob]

Shouldn't need to change the chain length. BUT depending on how many miles are on the old cassette and chain you may need a new chain to go with the 12-23 cassette.

 

[cydswipe]

I swap between 11-23 and 12-25 frequently, never any worries.

 

[skyliner1004]

Along the same lines will changing wheelsets with 2 different cassettes (12-25 to 12-26) require a rd adjustment? The weird thing is that the spacing near the hub is a little different between the two rear wheels.

 

[cxwrench]

in that case, yes...
you'll know...if you put a wheel in and the shifting adjustment is off, guess what?