I'd like to get an ultegra 11-28 cassette (11speed) to mix with my 12-25 and end up with a 12-28 by removing the 11 and subbing in the 16 (I know I'll need to use the 12t small cog from the 12-25). First, will this work? I can't find a break down of what cogs are riveted together on the 6800 cassettes.

Second, does this chain look long enough to work with the 28t? I do have the links I removed but would adding them back negatively affect the strength of the chain? It's a dura ace 9000, btw. Thanks!

That chain is way too short for your present setup. The current generation works pretty well cross-chained, but I would say you need to add two links to your present chain in order to accomodate a 28T.

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This shows which cogs are ganged: http://techdocs.shimano.com/media/techd ... 799947.pdf
Ultegra only gangs the last three cogs so what you propose will work. You should use the 12t lock ring on the 12t last cog. If it's like 10sp the 12t cog from either cassette will work.

The chain looks ok for the 25t but would probably be too short for the 28.

agree with eric. That's at the limit.

With a 50/34 in front and 12/28 in back you will have a total of 32T max takeup, which is about the maximum that that RD will handle, and only then if the chain is very carefully sized.

That job is much easier if you use a removeable link chain, which allows you to work down the the best length.

I use KMC.

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So let's just say I'm drivin' this buggy...
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So far, the KMC links are not reusable, however, they're much easier to replace (at $5 each) than breaking a Shimano chain.

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Technically I believe you are correct, however I've certainly had them on and off during fitting sometimes with no ill effects. Plus if the bike is on a stand for installing the chain, you can put the link 1/2 together just to establish correct length, then engage the link fully when you are satisfied that it's right.

If OP's setup is 10-speed then I'd reccomend Wipperman Connex which I used to use. Still don't think they've got around to making an 11-speed chain. SRAM also makes links.

_________________
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

The KMC links aren't reusable??!?? I've been reusing mine, for the life of the chain it came on. Am I going to die?

BTW I carry an old one in my seat bag, along with a multi-tool that can function as a chain tool (an old Ritchey CPR-9, no longer made, 56g). I've not had to use either for myself but they have come in handy for other people while on group rides. One guy broke his hanger in half when the derailleur caught in the spokes, we converted his bike to a single speed so he could ride home.

This is what KMC have in their Q&A



So @gabe is only correct when referring to the 11-speed connectors, and even then I've certainly had them off and on a few times with no ill effects.

_________________
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

They say it is should not be reused. But while I am changing my frame, I wanted to try if the missing link is strong enough to be used second time.
It is.
Its been around 1500km and it is still working.
I am carrying an extra missing link in my jersey pocket all the time, just in case, but I can say that there is no problems so far.

I definitely will not use the same link one more time, since I can actually see that it is weaker now while locking it, but using the same link second time should not be a problem I guess.

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Thank you for the help. I'll be ordering an 11-28 and new dura ace chain very soon!


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The Dura Ace chain is pretty good, but I would get a KMC X10SL instead… simply a better chain, better flexibility (more supple) and wears better (longer life), plus super easy to take off to get it really clean. That it's less expensive is just an added bonus.

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Audiojan, I've thought about kmc but I'm running 11 speed and the 11 speed model is more expensive than the DA as I usually by all my drivetrain parts from the UK.

Similarly, I use a 10spd link on the stand to set the length before fitting the 11spd link.

The re-usability of KMC 11 spd links has been discussed in another thread. Although KMC recommend not reusing them it does appear if you're careful they can be re-installed.
They are a quite a tight fit compared to the 10 spd. The KMC removal pliers make it easy though.

I have also 'reused' the 11-speed links after removal with Park Master Link Pliers (MLP-1.2) typically for cleaning but most recently while moving groupos to new road frames with no ill-effects.

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Michael - The Anaerobic Threshold is neither...

Sorry, I should have qualified my statement. The 10-speed versions are reusable, but the 11-speed versions are not. It's cheap insurance to replace it, so I do, when I swap to a new chain (which is the only time I ever take the chain off).

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Madone 4, SpeedConcept, Cobia

I own a lot of Treks.