Hi
all my wheels weaponry are shimano 10s freehub(zipp404carbonclincher lightweight obermayer shimano DA WH7850cl24 etc..)
I looking to put new DA in my new project bike
can i put the 11s cassetes of new DA 9000 in my wheels that in allready use with 10s cassetes?????

no

Welcome to the world of forced obsolecense.

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2010 Trek Madone: viewtopic.php?f=10&t=115249
2012 Trek SpeedConcept
2012 Trek Cobia
2013 Trek Superfly: viewtopic.php?f=10&t=115542" onclick="window.open(this.href);return false;

You should be able to remove a cog from a few of the 11 sp cassettes(13/14/15/16) to use it on a 10sp freehub.

For the Lightweight, if it's a DT freehub, just get the DT 11sp freehub. Dish difference is less than the allowed tolerance, so it may actually improve dish if it's erred to the other side.
Zipps, if they're 88/188 hubs, will either be convertible to 11 or Zipp will rebuild it with an 11sp hub for a small fee.
If you're going to drop a cog off an 11speed cassette, best way to do that is to get one that starts with an 11t, and leave that one off. Then you won't have a funky jump in the middle. Only issue, and I just checked, is that there are no serrations on the 12t cogs anymore unless it's a 12t first position. You could Loctite it or possibly use the 12t cogs from your numerous 10sp cassettes.

A 12 and 13 tooth cog from a 12-25, or 12-28 cassette would be ideal allowing you to turn an 11-23/25 into a 12-23/25 ten speed. Anybody know if it's possible to source just those two cogs from Shimano?

This is what I've seen suggested.

Take a shimano 11-speed cassette (11-12-13-14-15-16-17-19-21-23-25), drop out 1 cog and 1 spacer (the 16) to make a 10-speed cassette (11-12-13-14-15-17-19-21-23-25) with perfect 11-speed spacing. Mount this cassette on any 8/9/10 speed shimano compatible rear wheel with one standard (1mm thick) shimano cassette spacer behind it. Set up your 11-speed derailleur and shifters to just use 10 "clicks". Now you're set.

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