lcrider

I have a 11-28 on my 10 speed Ultegra (compact double 50/34) setup, but live in the low country (read flat). I almost never ride on the small chainring or on the 24 or 28 tooth sprockets, so I was thinking about going to a 12-23 cassette and saving the other one for any travel to hilly locations.

I've never changed a cassette before, but it looked pretty straight forward and looks like something I want to be able to do. Will I need to take a link out of the chain as well? Is there any reason I shouldn't make this change?

10 Wheels

Your chain should be ok.

datlas 

I vote to make the change.

You will need a cassette tool and a chain whip. You may end up needing to remove a link or two on your chain but I suspect you won't have to.

Performance has the ultegra cassettes on sale for 69.99 last time I checked, btw.

mechBgon

When you make that change, note the 1mm ring-shaped spacer that goes on the hub before the cassette and make sure one's in there, unless you have one of the rare Shimano hubs that don't need one (their freehub body would be aluminum).

Before going 12-23, try a downwind sprint in your 50 x 12, and/or a fast descent that you like to pedal down, to see if that's a high-enough gear for your needs. If it's not, consider an 11-23 instead.

hammond9705

Changing cassettes is easy and something riders should learn how to do. As mentioned, you will need a chain whip and cassette tool, but you can get them cheap. If you need instructions, see the Park Tool web site

datlas 

Sorry for the mini-hijack, but while we are on topic I am wondering if one should/should not put any grease (or other prep) on the freehub body before putting the cassette on. I have a new set of wheels and am wondering about that.

Homebrew01

No need to. They are not moving parts, and won't sieze up the way seatposts can.

datlas 

Thanks, that is what I thought, but wanted to be sure. Of course I grease anything with threads.

bryceman

I have a 12-23 Ultegra cassette I was going to sell here soon if you were looking to buy one?

Barrettscv 

I also like the 11-23 option, and I use this with a 50 & 39t standard crankset.

prathmann

No need to do anything to your chain length since it's currently working with a wider range on both the high and low end than your proposed new cassette. You may want to go back to your current wider range cassette for trips to hillier areas so you wouldn't want to reduce the chain length since then probably need to add those links back in to convert back.

But if you've got quite a few miles on your current chain you might want to check it for wear before putting on a new cassette. A worn chain can result in faster wear of the cogs on the cassette. If the chain is near the end of its life then you'd be better off replacing it and the cassette together.