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  1. #1
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    Cannondale Rize Seatpost diameter??

    Hi,

    I have recently bought a second hand Cannondale Rize 2009 frame, I think its the four (aluminium version).

    I have checked all over the internet and found that the seatpost size should be 31.6 with a 34.9 clamp.

    I bought a seatpost in that size and its too wide, I can slide it in a little but it's definitely too snug. I tried my 30.9 thomson and its fine. My issue is, when you look at the slot behind the seatube (just underneath the clamp) there is a tiny bit of space around the seatpost when its inside the seatube... Is this normal?

    It does seem like 30.9 is the right size but just wanted to check if anyone else knew.

    Thanks

  2. #2
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    The seatpost and clamp sizes are definitely 31.6 and 34.8-35mm. The seatpost is a tight fit so just carefully insert it using some slick honey or carbon paste if it's a carbon seatpost.

  3. #3
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    I thought that but its tight to the point where it takes a lot of force to get it in. Which is why I thought it might 30.9.

    I tried to put the new post in and ended up scratching the hell out of it in the process.

    Should it really be that tight?

  4. #4
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    The post size is 31.6. If the fit is that tight then the seat tube needs to be honed out with a flex hone. Same thing happened to me but once the seat tube is honed the post goes in smoothly and no longer leaves scratches all over it.

  5. #5
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    My 2009 rize also has a 31.6mm seatpost and 34.9mm clamp. In my case, the seatpost slides just fine without forcing and scratching it (good since is a carbon one, I use FSA k-Force SB25 31.6mm)

  6. #6
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    I got it fixed, the problem was a little bit of rough grit on the inside of the seat tube. A file, clean and small amount of grease did the trick.

    Thanks for the help

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