Viewing 12 posts - 1 through 12 (of 12 total)
  • Dropper post diameters
  • thered
    Full Member

    Is there any benefit to a 34.9 dropper in a 34.9 seatpost?
    Is there any issue in shimming a 31.6?

    1
    squirrelking
    Free Member

    Benefit of shimming is you’re not going to get the same seizing issues. Use a long plastic shim and it’ll be fine, I’ve run a 25.0 Thomson post inside my Trailstar at 26.8 with no issues using a USE (IIRC) plastic shim.

    escrs
    Free Member

    No issue shimming a 31.6 seatpost for a 34.9 seat tube

    Ive been doing for 3+ years now with no issues

    Just make sure you use a good shim, i have a USE alloy one

    https://www.sjscycles.co.uk/seat-posts/use-seat-post-shim-316-mm-to-349-mm/

    honourablegeorge
    Full Member

    thered

    Is there any benefit to a 34.9 dropper in a 34.9 seatpost?

    Bigger tube in theory should make it stiffer, less prone to flex, which might mean it wears less. BikeYoke seemd to think this was the case.

    Onzadog
    Free Member

    How many frames are using 34.9mm seat posts these days?

    thols2
    Full Member

    I run 30.8 posts in my bikes (apart from my commuter, which has 27.2 mm). This means that it will always be possible to swap the post to another bike just by changing the shim. Not having to worry about the post seizing to the frame is another benefit – if you use a metal shim, grease the outside of the shim but keep the inside dry to avoid the post slipping.

    scruff
    Free Member

    Random thread resurrection.

    Anyway, any tips on getting a post out thats stuck in a carbon frame, does WD40 work with carbon?
    I was just going to put an old saddle on and whack it with a big hammer.

    chiefgrooveguru
    Full Member

    You could try freeze spray to get the post to shrink a bit too. I don’t know how much carbon expands with heat but when I had a post stuck in a steel frame I did freeze spray on the post and boiling water on the frame before hitting the post in a few mm with a mallet and then twisting it out with a pair of big G-clamps.

    a11y
    Full Member

    Anyway, any tips on getting a post out thats stuck in a carbon frame, does WD40 work with carbon?

    Give The Bike Works in Stirling a try if you’re local – Iain’s got a purpose-built device for removing stuck seatposts. He’s never failed to remove one to my knoweldge. For clarity, he’s a mate of mine.

    https://www.facebook.com/p/The-Bike-Works-Stirling-100063816411437/

    Although I’m sure there’ll be similar elsewhere in the UK.

    5lab
    Full Member

    with a carbon frame it shouldn’t have the chemical bond that you can get with alloy/steel combo, and heating won’t work so I’d just be throwing some anti-seize in there for good measure (no idea if it helps in this scenario), clamping the seat clamp in a vice and twisting the frame in alternating directions

    peanutcracknell
    Free Member

    JL cycle works in the forest of dean also have a puller for removing stuck posts if you’re in that area.

    scruff
    Free Member

    Got the frame rotating with the post in a vice and then left it upside down with half a can of GT85 down the seat tube.
    Even had the pleasure of a rounded Shimano crank pinch bolt to deal with after that.

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