Swapping cassette sizes...what to adjust?
11-02-05, 04:38 PM
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Swapping cassette sizes...what to adjust?
I'm going from a 12-25 to a 12-27 cassette on my road bike and wondering what I have to adjust on the rear derailluer? I'm thinking the high/low screws should be fine but do I need to adjust how close the top derailluer pulley wheel is to the largest sprocket? Also do I need to add any links to the chain?
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Thanks
11-02-05, 05:24 PM
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You need to adjust the "B-tension" screw to keep the derailer pulley from hitting the largest sprocket. See https://www.sheldonbrown.com/gloss_ba-n.html, there's a photo right there at the top with an example of the B-tension screw. Most likely you'll need to "tighten" it (turn it clockwise) to move the derailer away from the cassette.
Not sure about the chain length, but also from the Sheldon Brown site: https://www.sheldonbrown.com/derailer...ent.html#chain might be useful in determining whether you are at an optimal length.
Not sure about the chain length, but also from the Sheldon Brown site: https://www.sheldonbrown.com/derailer...ent.html#chain might be useful in determining whether you are at an optimal length.
11-02-05, 05:24 PM
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You *probably* don't need to adjust anything. The length of your chain will dictate the position of your rear derailleur. Park Tool has a very good page on chain-sizing that will help determine whether you need to change your chain length.
If you are changing your cassette due to wear, you should put on a new chain anyway.
If you are changing your cassette due to wear, you should put on a new chain anyway.
