mrbUSA

Just purchased new wheels from a reputable and noteworthy BF'er and am awaiting delivery.

I want to purchase a new cassette. I currently have a 10spd 12/23 105. A 10spd DA CS7800 12/21 is about $110 and an Ultegra CS6700 12/23 is about $100. Would there be any significant/noticeable changes upgrading to the DA? The same from going from 12/23 to 12/21? I'm more of a spinner than masher. Any information would be appreciated.

Thanks, Mike

operator

Just stick with the 105.

kycycler

Why not use a SRAM?? Seem to last me longer than the shimano.

operator

If the rest of his drivetrain is shimano there is no point in going sram.

mrbUSA

Thank you for the input.

StanSeven

???

black_box 

similar situation for me, I have a 10spd ultegra 12-25 and dura-ace R/D, need a new cassette for off-road/cross. 38/48 up front and I'm a newb, so taller gears in back might be good for sloppy conditions.

Can the 7700 R/D handle an SRAM 11-28? otherwise I'll probably do a 105/ultegra 12-27. Do I need another chain for either of those? I don't have any extra links but maybe a 2nd chain would be a good idea for the new cassette?

Carbonfiberboy 

Ultegra. Dura Ace is lighter because it's partly titanium, which wears a lot faster. If you don't use the 23 much, sure the 21 will be nicer because you'll get an extra ratio. But if you're a spinner, I'd think you'd want the 23. It's a funny thing - when I bought my Trek, the Dura Ace model came stock with 12-23. The Ultregra gruppo came with 21-25. Maybe they still do, I haven't looked. But I thought that was an example of pretty funny classism. Hey dudes, some TdF guys used to be coal miners, fixed their own bikes. So don't be afraid of using a bigger rear cog. My advice.

Halfast

I have the short DuraAce rear der and when I went from a 12-23 to a 12-27 I had to add a couple of chain links.

black_box 

So I found this: (Big Ring-Small Ring) + (Big Cog-Small Cog) = Capacity Required.

How do I determine which cage size I have now? My 12-25 needs a 23 link capacity, the SRAM 11-28 would need 27.

krems81 

you'll need a couple extra links. I'm not sure what the going wisdom is on adding links to 10 speed chain. I mostly build single speeds and older 6-8 speed drivetrains. Most rds will handle 28t.

joejack951

Adding links to any flush pin chain requires either using the Shimano special pin or a quick link. You CANNOT safely reuse pins on these chains.

If you size the second chain correctly, you should be able to use the longer chain with either cassette.

Al1943

I've ridden both D-A and Ultegra. I cannot tell which wears faster. The D-A is much lighter which would help with climbing but probably not a noticeable amount . The Ultegra is shinier. If you are more of a spinner I don't see why you would want a 12-21. If you like your 12-23 then stay with it. The differences between 105, Ultegra, and D-A are weight and cost.

Al1943

Your derailleur can easily handle any of these options. I doubt that you would need to add chain going from a 12-25 to a 12-27. You would need to check to see that you can shift onto the big to big combination smoothly and without maxing out the derailleur's forward travel.

Al