Make your own shim: 31.6 – 30.9

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  • Make your own shim: 31.6 – 30.9
  • Olly

    Strikes me that the difference of 0.7mm, between 30.9 and 31.6, isn’t worth spending nearly tenner on a seat post shim for?
    I’ve just mocked up a shim from a sheet of 0.5mm, and obviously it’s too snug (total 1mm), but I was able to make it nice and long, and was also able to cut it with a Stanley knife.
    Anyone running a pikey seat post shim?
    Any suggestions as to a source of 0.35mm sheet i might find around the house this evening?

    Piston head cans are 0.01mm
    Might try a Hob goblin next.
    Beans for tea?
    They make them out of plastic too, don’t they?

    Premier Icon Shackleton

    Given my experience with shims and posts slipping I’d stick with your thick one and thin it down somehow (wet and dry? ).

    Premier Icon cynic-al

    One word:

    Coke can

    Coke can is two words.

    Spoon, now that’s a single word.

    Whack it with a hammer until it is the required thinness

    Premier Icon martymac

    I run a shim on my surly, it’s a USE one, made of plastic.
    Doesn’t slip or anything, well worth a tenner imo.

    Premier Icon krixmeister

    I ran a cut-up can of Tennents lager as a shim, for 31.6 to 30.9, for about 5 years. I wouldn’t spend money on a shim for this purpose, but I a a cheapskate.

    Premier Icon frankconway

    Use hammer, carefully, on existing shim to achieve required thickness/thin-ness; soft-faced if you have one.
    Alternatively, use granny’s mangle.

    Premier Icon bedmaker

    Lindab galvanised steel guttering downpipe worked a treat for me. Ever so slightly thick for a full wrap. Probably a gap of 15mm or so.


    Strikes me that the difference of 0.7mm, between 30.9 and 31.6, isn’t worth spending nearly tenner on a seat post shim for

    If it makes the post fit the frame, it’s worth it. I have used drink can shims plenty though, they’re just a bit fiddly. Fine if you fit the post permanently, PITA if you need to raise and lower it frequently.

    Premier Icon Trailrider Jim

    Why are you questioning the value based on shim thickness? If you need the right tool for the job, a ten quid shim’s a ten quid shim, regardless of thickness.

    35 years of riding MTB. Tried coke can shims a couple of times but that was 20 years ago. Ok to try on a cheap frame and post to get it working, maybe on a commuter for example, but just buy the right shim on anything else. Your frame and post will thank you for it.

    Small tip – if you want to make sure a post is supported longer than a normal shin then buy 2 shims and grind off the lip on one and mount it lower down. A small dab of glue helps to keep it there if you ever want to pull it out without the shin dropping down the seat tube. Useful for bikes with longer sections of seat tube above the top tube

    Premier Icon tomhoward

    Some people value their time differently I guess

Viewing 13 posts - 1 through 13 (of 13 total)

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