Swapping 12/25 and 12/27 Cassette Every Weekend
 

I typically like to race criteriums with a 12/25 Dura Ace cassette on my Zipp 404 Tubulars, but I prefer a Dura Ace 12/27 on road races the following day.

Questions:

1. If I have a shimano 10spd cassette lock ring tool, can I just swap cassettes anytime without derailleur adjustments as long as my 12/25 and 12/27 both use the same spacer?

2. I notice that the lock ring makes a click sound and will not tighten further when it is tight. Is there danger in tightening the lock ring to the point of hearning or feeling that click? Am I over tightening the cassette lock ring or is that even possible? I assumed it was designed so that you can't over tighten it, but I figured that I should ask before I make an incorrect assumption and ruin something.


My goal is to just bring my rachett with the lock ring tool to every road race on Sunday and quickly swap cassettes with no further adjustments prior to racing, but I'm not sure if I can make it that simple. Thanks in advance for any clarification and/or feedback/suggestions/advice.

You should be able to change these cassettes in about 5 minutes with no adjustments needed. I've done this many times. The lockring torque specs are shown on the lockrings. It needs to be plenty tight. Looseness in the cassette cogs can damage the freehub splines. It's not necessary to use a torque wrench for this application once you have a good feel for what is "tight".

Al