Home Forums Bike Forum Seat Clamp Alignment

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  • Seat Clamp Alignment
  • honourablegeorge
    Full Member

    So – I always align my seat clamp with the bolt facing forward, regardless of where/if the seat tube is slotted, to keep it away from the spray of crap from the back wheel.

    I would never set up like this, for example.

    Is this something people agree on, or another one of those ongoing arguments?

    bluebird
    Free Member

    I align the split in the clamp with the split in the seat tube. Whether it matters I have no idea.

    letmetalktomark
    Full Member

    Clamping side aligns with ST slot. Always.

    legend
    Free Member

    It goes where the slot goes – because reasons.

    honourablegeorge
    Full Member

    I need reasons better than my reason to change. If the slot is facing the back of the bike, I reckon it’s in the wrong place.

    otsdr
    Free Member

    If it is not aligned with the slot the clamp will need to slide on the frame in order to actually do the clamping; if the interface is not greased, you can end up breaking the aluminium bolt.

    bigyan
    Free Member

    Depends on the manufacturer;

    https://media.specialized.com/support/0000003979/IG0370.pdf

    <div>The seatpost collar should be positioned so that the collar slot is oriented 180 degrees opposite from the seat tube slot (fig.2). This dramatically</div>
    <div>reduces the possibility of the edges of the seat tube deforming and digging into the seatpost, which can compromise the integrity.</div>

    <div>Some frames have 3 slots, some manufacturers put an offset angle slot in the clamp and a mark for the frame slot.

    It is not that common to see pinched seatposts from having the clamp and slot in line, but it does happen with some frame/seatpost/clamp combinations.</div>

    otsdr
    Free Member

    Yes, but this is for a very “special” carbon seatpost; plus, they then go on to say

    Composite seatposts are non-metallic, they cannot seize in the seat tube.

    , which kind of ruins their credibility.

    molgrips
    Free Member

    I make the splits opposite, because I think it spreads the load more evenly around and avoids pinching a carbon post. Which incidentally I have also had seize in the frame.

    andyl
    Free Member

    I think I normally position them 180deg out but it depends on the slot, I always try and put the QR mechanism forward out of the way of crud from the back tyre.

    Always seem as though 180deg helps avoid crap build up in the slot, not sure if it actually works or matters in reality.

    trailwagger
    Free Member

    I leave it wherever the manufacturer put it, they should know.

    alanf
    Free Member

    If you had a quick release clamp, which way around would you put that?

    Do the same with the bolt clamp.

    honourablegeorge
    Full Member

    I’d be doubly keen to keep a QR out of the spray from the back wheel.

    geex
    Free Member

    ^^ They can be cleaned and re-greased. Infact. It’s worthwhile doing it from time to time. Save up some of that doubly keeness and do that too. ;)
    On my only bike left with a QR seat collar the clamp isn’t aligned with the slot or opposite it.
    OMG WTF!!!  It’s positioned offset slightly so the lever can’t catch on anything.

    MSP
    Full Member

    I put it 360deg round where everyone else does.

    geex
    Free Member

    lunge
    Full Member

    Not aligned with the slot, was told this by a mechanic decades ago and have bought a few new bikes that said the same.

    cynic-al
    Free Member

    One of these things that just doesn’t matter.

    Someone came up with the way of lining them up 180 degrees to make them look clever.

    Unless tolerances are way out or you are a gorilla, shouldn’t matter.

    Dickyboy
    Full Member

    180 degrees from the slot – one clamp I have even has a pimple on it so it can’t be installed any other way.

    thisisnotaspoon
    Free Member

    I’ve always lined them up, because that’s effectively what the integrated one on a lugged frame does, never even considered that there were other opinions!

    As for why the split is on the back of the tube (unless the manufacturer makes a feature out of it’s britishness being on the front of the tube), I assumed that was also a hangover from integrated clamps and the slot generally being behind the tp tube on a horizontal frame, you couldn’t go the other way on a road bike.

    And on that note, is there any good reason why steel frames don’t have a brazed on clamp? Surely it would be smaller and lighter?

    scotroutes
    Full Member

    A Giant seatclamp to mount a rack…

    Another Giant seatclamp to mount a rack…

    Does anyone still think it makes any difference?

    deadkenny
    Free Member

    Was told not aligning with the slot can pinch in the wrong place and in the case of carbon frame could end up cracking it. Funny enough, there’s a little bit of a crack in my old c456 frame where I was clamping it 180 opposite to the slot. But could be coincidence.

    I’ve got them mixed up on my other bikes though, possibly just from wherever it was last or when I originally got it.

    Also, with a quick release and external dropper, the lever can snag the cable on dropping if on the same side.

    iainc
    Full Member

    all the bikes I have bought as complete units, and there have been many, have had them aligned with slot

    mattyfez
    Full Member

    Double post

    mattyfez
    Full Member

    Was told not aligning with the slot can pinch in the wrong place

    Does it really though… Surely it will tighten evenly all the way round as you tighten it unless the clamp is too small or big?

Viewing 25 posts - 1 through 25 (of 25 total)

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