@ Elviento,

once you can log some miles it would be much appreciated if you could give a ride report for;

Full Campy bike running the D Ace 9k cassette

and a

Full D Ace 9k bike running the Campy (11) casette.

Okay so I have got a partial DA 9000 groupset including CS-9000 11-28T cassette. I do not as yet have a 11-speed compatible wheelset therefore I'm going to start off as 10-speed while I decide on a suitable wheelset. I'm going to therefore run the 9000 cassette as a 10-speed by removing one of the sprockets.

My question is, what would be the best sprocket to remove?

The 11-28T cassette has the following ratios:

11-12-13-14-15-17-19-21-23-25-28

I have to keep the 11T don't I as this is the only sprocket compatible with the lockring?

In these situations it helps to look at what Shimano does with the rest of the cassettes they offer for comparison.

here are the 7900 (10)spd cassettes
http://techdocs.shimano.com/media/techd ... 728250.pdf" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

here are the 9000 (11)spd cassettes
http://techdocs.shimano.com/media/techd ... 807221.pdf" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

The DA9K (11) spd, 11 - 28 cassette has to be the most "unfriendly" in terms of being easily modified. Like all the cassettes you won't be able to pull any of the last (5) cogs. If you pull the (12)tooth cog it may 'feel odd'. If you pull the (17) you would have a jump from the (15) to the (19), not good.

I believe you can pull the (11) tooth cog with no problems. You would have to install a lockring for a (12) tooth cog. And you would need a spacer behind the cassette.
In this Thread the O.P. pulled their (11) tooth cog.
viewtopic.php?f=10&t=108205" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Mid way down on the 2nd page the O.P. describes pulling the (11)tooth cog.

Swapping the 11 - 28 you have for an 11 - 25 would be ideal. You could easily pull the (16)tooth cog.
Let us know how it goes.

^Thanks for the reply, most helpful.

So if I remove the 11T, I'll need to change the lockring. The spacer that I need behind the cassette will presumably be included with the 9000 cassette? No other spacer needed?
Need to find a 12T lockring then.

Thanks,

Right, find a lock ring for the (12) tooth cog.

The DA9K wheels are shipping with the spacer required to run the wheel as a (10) spd wheel.
Since that's what you're going to do, run a (10)sp cassette, contact a bike shop and get the spacer you need. It doesn't have to be a DA9K spacer. Many companies make cassette spacers. Just make sure you space it for a proper fit of the cassette.

Let us know how it goes.

Elviento,
have you logged any miles with the 'crossed up' combos, Campy & DA9K?

Campagnolo 9 speed was introduced in 1997 and the freewheels work with 11spd , thats 17 years of backwards compatability, only in 2008 did shimano make their 9/10spd freewheel splines compatible, now with 11 there's another different standard thats 6 years since a major revision, and apparently campagnolo 11spd freewheels/cassettes work with new 11 spd Shimano .

I think you're off on your Shimano compatibility. I have 7700 hubs, 8sp hubs introduced in 1997, that can handle a 10sp cassette. The 7800 hubs introduced in 2008 were 10sp only, when Shimano tried a new (to them) cassette body architecture, but the 10sp cassettes were able to be fitted to previous generation Shimano hubs. All 10 sp hubs subsequent to 7800, ie the 7850 and 7900 hubs, were able to take 10/9/8sp cassettes.

The history part is completely off on most parts.

The outgoing 10s 'low spline' specification was introduced on the 8 speed hyperglide spline in 1992. And all the way till 7900, they have been completely compatible forward and backward compatible. 2012, after 20 years, they finally introduce a new standard that's still backward compatible to fit all the 8,9 and 10 speed cassettes. ( albeit, you can't fit 11s cassette on the older hubs )

The only abnormally along the way was during the introduction of the 7800 10s group, they tried to introduce the new 'tall spline' hyperglide freehub (in a bit to use aluminium freehub body) that was not backward compatible with older cassettes. BUT ... the 10s 7800 cassettes were still completely back compatible with older hubs and splines. But that was quickly phased out within less than a year due to backlash.

As for Campag ... guess it was conveniently forgotten about what happened when they introduced their 9 speed freehubs huh ??

Has anyone tried using a cs-9000 cassette with 10 speed wheels by removing one of the cogs? If so please let us know how you went!