new road wheel/cassette question

[jjcp]

Hi All,

A newbie question.

So after purchasing my first new set of road wheels. I decided to mix the gearing and bought a new cassette aswell. Now here is the question/problem: 1) why is the middle part of the cassette loose? i have tightened it according to the shimano intructions.Do i need spacers? 2) it wont shift to the biggest cog. Do i need to adjust the rear derailleur? 3) there are some noise when shifting up/down. I am pretty sure its the chain rubbing against the cassette.

Here are the specs:

Groupset: Full Ultegra 6700, cassette: 12-25

New cassette: 11-23

thanks all

[Bentnose]

Are you sure you aren't missing some spacers in the middle, I just put a new Ultegra cassette on my bike and it was nearly all loose sprokets with loose spacers in between, can you see a spacer between every cog?

[open roader]

+ 1 spacer placement most likely.

Check, check, double check......?

A 25 tooth cog is not going to create a chain / cage length issue and the rear derailleur should maintain it's alignment if you are switch between like for like cassettes. My guess without seeing the set up is that the biggest cog (25t) is set too far into the hub for the rear derailleur to engage meaning a cog spacing issue..........

[jjcp]

it looks like I need a mavic spacer instead of the shimano ones.

[biker jk]

When I changed a cassette on a friend's Mavic rear wheel (some time ago now) I had to use both the Mavic spacer and the Shimano spacer.