How to change a casette?

[DebW]

is the chain whip tool necessary, or is there some other tool or combination of tools that can be used instead?

There is also Pedro cog wrench which can be used instead of a chain whip:
http://www.nashbar.com/profile.cfm?c...eid=&pagename=

But it only works on 11 or 12 tooth outer cogs. A chain whip is more versatile since it fits any size cog in any position. If you have to buy a tool, get a chain whip. Or you could make your own from a piece of metal bar and some old chain.

[bcipam]

I switch out my 12-27 for a 12-34 (I put a XTR cassette and derailleur on the rear) and I did need a new chain - the original was just not long enough. If you keep the longer chain on when switching to the 27, then it will be too long and you will have chain slack. There really is a big difference between a 27 and a 34 not so much if you are switching out a 27 for a 25 or 23. Suggestion - have a chain for each cassette. Use a Conex link so it's easy to remove and replace. When you are using one you can be cleaning hte other. Probably not a bad idea. Also you will need a different derailleur for the 34. The regular Ultegra or whatever you run just isn't long enough. You need a mountain bike or touring derailleur.

Note: I put the XTR on3 years ago for my Utah trip but never replaced it with the 27. Turns out I like having the 34. Are you sure you will be changing the casettes out?

Also to change out a cassette you need two tools - a chainwhip and I forget the name of the tool that goes in the middle. One holds the hub tight , the chainwhip loosens the cassette. I would got o your LBS and ask them to show you how to change out the casette and what tools you need. Neither was particularly expensive.

Also there is a cheap tool you can buy that measures chain wear. I think wear varies for each rider and how hard they mash their gears.

[Triskeliongirl]

I switch out my 12-27 for a 12-34 (I put a XTR cassette and derailleur on the rear) and I did need a new chain - the original was just not long enough. If you keep the longer chain on when switching to the 27, then it will be too long and you will have chain slack. There really is a big difference between a 27 and a 34 not so much if you are switching out a 27 for a 25 or 23. ... Also you will need a different derailleur for the 34. The regular Ultegra or whatever you run just isn't long enough. You need a mountain bike or touring derailleur.

Note: I put the XTR on3 years ago for my Utah trip but never replaced it with the 27. Turns out I like having the 34. Are you sure you will be changing the casettes out?...

On this particular bike, I have an XT dearilleur, longer chain, and 11-34. But, its not clear the chain will have too much slack when I move to the 12-27, since it seems to me that since 12 and 27 are both contained within my 11-34 casette, then the slack should be the same when in those gears. But, I'll see when I go to do it. I know I don' tlike the 11-34 for everyday use, cuz the gaps between gears is too large for fast club riding, etc., BUT, if I go to the real mountains or tour I will want it. I am also curious to see how I like the XT rear dearailleur with the 12-27. If its OK, when my racing bike needs a new rear derailleur I may put an XT or XTR on instead of the ultegra I have, again with the idea that I can easily swap casettes ore wheels as needed for the terrain, since I only have a compact double, and not a triple on both bikes.

[bcipam]

I toy with putting the Ultegra 27 back on - as the XTR 34 is alittle clunkier - bigger changes/jumps between shift etc but I love having the small granny gear when I need it. Helped me out in Utah and Texas on some long steep climbs!

[Pedal Wench]

I just swapped out cassettes for the first time this weekend. If I'd known it was so easy, I would do it more often. Now that I've got the tools (gotta LOVE that chain whip!) I'll remove the cassettes to clean them too - much easier to clean them off the wheel.

[DebW]

On this particular bike, I have an XT dearilleur, longer chain, and 11-34. But, its not clear the chain will have too much slack when I move to the 12-27, since it seems to me that since 12 and 27 are both contained within my 11-34 casette, then the slack should be the same when in those gears. But, I'll see when I go to do it.

Your XT derailleur should wrap up the extra chain just fine. If you wanted the fastest and crispest possible shifts, you'd shorten the chain and the derailleur cage. However, since you want to swap between 12-27 and 11-34 cassettes, far easier to stick with your current chain and derailleur. Try it and see how you like the shifts.

[SadieKate]

I swap cassettes all the time. The bike that gets this treatment the most has the chain length set for a 32T cassette but I'll swap to a 25T when I want closer-spaced gearing. I use the same chain for both. Works just fine.

Bubba does the same with his cross bike, swapping a 30T for a 25T.

[Triskeliongirl]

Thanks for all the great advice! I went to my LBS to buy the tools, and the guy ended up changing it for me as he showed me how to do it, but it really did seem easy. I was glad he showed me though, cuz the tricky part was lining up the cogs correctly and it was just easier for him to show me than tell me. I put the wheel on, and it shifts smoothly without any derailleur adjustments. I think I'll take apart a really old wheel to practice on this weekend, to be sure I will remember what to do when I have to do it again.

[velogirl]

A chain whip is more versatile since it fits any size cog in any position. If you have to buy a tool, get a chain whip. Or you could make your own from a piece of metal bar and some old chain.

And how cool is it at a cocktail party when you can tell that cute guy about using your chain whip?