Convert 12-17 to 11-27 Shimano 6600
I have a 6600 12-27, and a buddy said i could convert to a 11-27 by switching out the 12 for an 11T, and changing the lockring to an 11T lockring (the 12T lockring is to large diameter). So, I dutifully ordered up both parts, and tried to install them yesterday.
The installation went fine, but when I loaded the chain and starting turning the crank, the chain kept being picked up intermittently by the next largest cog (which is now the 13). After visually inspecting the two setups, its obvious that the spacing between the 11 and 13, is smaller than than the 12 and 13 and that is the problem. I have never heard or seen of an 11T spacer, so I am some what bewildered (I haven't talked to my friend yet). Any ideas? These are both near new Ultegra 6600 parts - a 12-27 group and a 6600 11T.
I suggest you don't listen to your buddy anymore.
12 teeth is a big enough gear unless you have odd chainrings - like a 46 tooth max or something.
In my experience, if a cassette part needs a spacer for normal use it will be included, but I am not too sure if this is always the case. A lot of cassettes used to come with a very thin spacer for use between the first and second cogs.
Is it possible you got a 10 speed cog to replace a 9 speed cog?
My buddy actually has it on his bike, but he has full DuraAce,if that makes a difference. I double checked and they are both 10 speed systems.
I feel i need the 11T is because i have gone to a compact up front for big hills - yes, we have big hills in california, but tend to spin out on the flats.
cycles per second
According the the exploded view of the CS-6600 at ...
the 12,13 of the 12-27 are identical to the 12,13 of the 11-23 and there is no special spacer for the top cog.
But that does not mean that you can swap an 11 in place of the 12. It only means that you can use your existing 12 in the 2nd position.
Compare the width of the built in spacers on the 11 and the 12. I don't have any 10-speed cassettes but I do have some 8- and 9-speed cassettes where the 2nd cog has a recess that the top cog nests in. The 13 cog may have while the 12 probably doesn't. If so, the 11 will sit too close to the 13. If this is the case, you could try putting the 12 back in and removing a different loose cog, say maybe the 16.
Originally Posted by bbrider77
If you can spin out a 50/12 combo on the flats you are a better man than me! At 100RPM that is about 32MPH!
Duraace vs Ultegra vs 105 vs Tiagra does not make a difference if everything is new and working properly.
I have taken cassettes apart in the past and reassembled them into new configurations, but the individual cogs were not designed to work with one another and they never shifted very well. Shimano makes their cassettes so each cog is desiogned only to work in it's current configuration, AFAIK.
Sorry to say it, but maybe you should just get a complete 11-27 cassette... or a 52 tooth chainring.