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Reynolds 531 tubes - seatpost

(15 posts)
  • Started 13 years ago by kaputnik
  • Latest reply from kaputnik
  • This topic is resolved

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  1. kaputnik
    Moderator

    So all I need to finish building my audax bike is a nice new seatpost in shiny plain metal. So I bought a 27.2mm one because I had test-inserted a crappy old one I have and that seemed to fit. Only the 27.2mm one I bought jammed about 4 inches in and scored badly on the way out, meaning it has been disposed of on eBay for a £9 discount. So today I picked up a 26.2mm one and it seems to be rattling about!? I've tightened the clamp and although it's "snug" now, it's easily spinable and I'm sure if I sat on it that it would sink straight into the seat tube...

    So was the first one just needing a bit of mallet action to get it to go home or should I tighten the clamp a lot more, on the new one (but that would cause the clamp to begin to bend - can you do this with steel?)

    At a bit of a loss...

    Edit - just checked Sheldon's database and it says "Dawes Audax 1997 27.2". So I just need to see if I can return my 26.2 for a 27.2 and whack it in with a mallet?

    Posted 13 years ago #

  2. Smudge
    Member

    Sounds like a friends which seems to be a vintage "inbetweenie"(tech term) size.

    My only advice (and you may like the first bit...) is to open a can of beer, drink it, then rinse out the can and take the tin snips to it, you should be able to make a nice long thin alloy shim to take up the slop.

    and if it doesn't work at least you got a beer out of it! ;-)

    Edited to add, I'm not a fan of mallets unless there is no option. Far better to have a brew, think about it and try and come up with a non-violent option. After all, you're not against the clock like a pro mechanic, you can afford the luxury of looking for a more elegant solution :-)

    Posted 13 years ago #

  3. chdot
    Admin

    Assuming it's butted 531, 27.2 is correct.

    Scratching is probably due to a slightly bent lug - perhaps because it's previously been used to hold an undersized seatpost...

    Smudge has the answer if you don't have the right size of sp.

    (Other beverage recepticals are suitable.)

    Tin snips maybe replaced by scissors.

    Posted 13 years ago #

  4. kaputnik
    Moderator

    Ok well I've managed to test-fit the old 27.2mm post down it by spinning it in with the saddle as a lever (no mallets were used in the insertion of this seatpost). I'll see if I can swapsy the post tomorrow for another 27.2, as it was too small it's not scored or damaged in any way. I will then just be persistent with my insertion techniques. If I can't return it, I'll try the tin solution. That way I at least get a beer out of it :)

    P.S. I'm on my second giant mug of problem-solving tea on this one!

    Posted 13 years ago #

  5. Wilmington's Cow
    Member

    Just remember to grease it!

    Posted 13 years ago #

  6. Smudge
    Member

    @Anth, Don't be ridiculous, that'd ruin the tea!

    ;-)

    Posted 13 years ago #

  7. kaputnik
    Moderator

    I always grease thoroughly before insertion. They taught us that in school.

    Posted 13 years ago #

  8. chdot
    Admin

    With posts measured to .2 of a millimetre 'perfection' is necessary - but - it also depends on the wonders of Reynolds (usually pretty impressive).

    If your post is getting stuck then obviously there is a problem with the tube. Could be original manufacturing - more likely to be a small 'fall over' knock - or an imperfectly fitted bottle cage boss.

    Of course you shouldn't need 4" of seatpost in the frame - unless it's really too small and there is a lot out of the frame.

    If seatpost sticks that far in, might be worth reducing diameter towards tip by rubbing with sandpaper - alloy really quite soft.

    Of course it's quite easy to get alloy seatposts to stick in steel frames PERMANENTLY - not good - so use plenty of grease.

    Posted 13 years ago #

  9. kaputnik
    Moderator

    Thanks for all the tips. I was going to saw down the end of the post anyway, but was told by a mechanic once to leave a palm's width of post in the frame i.e. 4 inches?

    I'm pretty sure the frame has been built up and then sat in a shop window for the last 15 years, judging by the condition of the bottom bracket and the dropouts at least (and having seen a photo of it on ebay). I did find the manufacturer's cardboard frame tag stuck in the bottom of the seat tube when I was inspecting it, which was rather cool. Half covered in paint spray that matches the frame.

    Posted 13 years ago #

  10. chdot
    Admin

    "leave a palm's width of post in the frame i.e. 4 inches?"

    Good enough advice,

    'These day's very long seatposts are common because of MTBs with sloping top tubes so it's easier to use frames that are 'too small'.

    Of course we are now in the realms of aesthetics as well as practicalities like length of top tubes and stem sizes for the type if riding you like.

    Whatever suits/fits.

    Posted 13 years ago #

  11. kaputnik
    Moderator

    Just remember to grease it!

    Having just dissasembled the STI cable stops on the tourer, EBC could take note of this piece of advice. Still trying to get one of them to move thanks to alloy-on-steel corrosion siezing the barrel adjuster solid.

    Posted 13 years ago #

  12. kaputnik
    Moderator

    Well the seatpost gauge in TBW measured it as a 27.0! Managed to return my 26.2 at least...

    Posted 13 years ago #

  13. chdot
    Admin

    "Well the seatpost gauge in TBW measured it as a 27.0"

    531 plain gauge(?)

    Or old?

    http://forum.ctc.org.uk/viewtopic.php?f=5&t=44266&start=0

    Posted 13 years ago #

  14. kaputnik
    Moderator

    Um I dunno. It was a piece of steel rod with stepped chamfering on the way down that you dropped into the tube until it rested and read off a scale?

    It's a 1997 531 competition frame.

    Posted 13 years ago #

  15. kaputnik
    Moderator

    Sorted!

    Sawed down a 27.2, pryed open the clamp a bit with a flathead screwdriver and leaned on the saddle with my bodyweight as I spun it slowly and it went in smoothly.


    Birth of a Bicycle

    Posted 13 years ago #

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