Viewing 40 posts - 1 through 40 (of 53 total)
  • How much should seatposts bend in use?
  • enfht
    Free Member

    On approx 20cm of exposed seatpost?

    14.5 stone fully loaded and I've noticed my FSA post really flexes under load and is starting to creak

    Would something like a Thomson post really flex any less?

    _tom_
    Free Member

    I'm about 17 stone and haven't noticed my thomson flexing or creaking. Quite a thin one as well (26.8mm) and its a good length out of the frame.

    davidmoyesismydad
    Free Member

    thomsons bend/flex aswell .mine does & im only 9st 6.
    infact the fsa one on my other bike does too

    jimmyshand
    Free Member

    See that thing that comes up quickly in front of you – trail, road or track – concentrate on that more. I have no idea if any of my kit flexes

    enfht
    Free Member

    _tom is your post used in a HT or FS?

    _tom_
    Free Member

    It's in a hardtail.

    enfht
    Free Member

    ally or steel ? 😀

    frank4short
    Free Member

    jimmyshand – Member

    See that thing that comes up quickly in front of you – trail, road or track – concentrate on that more. I have no idea if any of my kit flexes

    Post of the day!

    jimmyshand
    Free Member

    Glad you liked it.

    enfht
    Free Member

    I didnt think ally was meant to bend much at all

    clubber
    Free Member

    I think you've been reading too much magazine type faux material-science rubbish. All metals flex. Seatposts flex plenty and are usually just fine. I really wouldn't worry about it unless it actually bends (and I've bent a lot of them).

    Thomsons flex plenty too.

    Coyote
    Free Member

    I'm puzzled as to how you would measure how much the seatpost flexes. As said above, most stuff flexes. If you are genuinely worried then check the post for stress marks. I had a Ritchey post that started creaking badly. When I checked it had quite a few marks down the front.

    Hope this helps.

    njee20
    Free Member

    See that thing that comes up quickly in front of you – trail, road or track – concentrate on that more. I have no idea if any of my kit flexes

    +1

    KINGTUT
    Free Member

    If you really want to shit your pants, buy a carbon post hook your bike up to a turbo trainer and spend an hour marveling at the flex.

    enfht – Member

    I didnt think ally was meant to bend much at all

    I shall use this on the BS of the week thread on Friday.

    Marge
    Free Member

    Does anyone know if the VCLS seatposts are available to buy?

    I know they're fitted to Canyon & Cannondale complete bikes but I was looking for such a seatpost with no luck…

    edit: by the way – the 34.9mm carbon post on my Scale doesn't seem to bend very much at all. Ouch.

    Kieran
    Full Member

    IME;

    Bontrager Posts – Light but extremely flexy but never broke.
    FSA – V heavy, indestructable, slight flex.
    Thomson – Light, slight flex but not as much as the FSA

    KINGTUT
    Free Member

    Thomson – Light,

    I shall also use this in the BS of the week thread.

    enfht
    Free Member

    See that thing that comes up quickly in front of you – trail, road or track – concentrate on that more. I have no idea if any of my kit flexes

    Reminds me of the time when that strange grinding noise turned out to be I'd lost my back wheel. 😮

    Kieran
    Full Member

    I know they're fitted to Cannondale complete bikes

    Every Cannondale I've had over the past 6 years has come with an FSA post, Although looking at their website they now appear to be own brand or USE

    wwaswas
    Full Member

    Reminds me of the time when that strange grinding noise turned out to be I'd lost my back wheel

    Well, it does take a finely honed mechanical sense to determine that without having a quick glance to check.

    enfht
    Free Member

    To clarify, I believe my very flexy seatpost is creating some occasional creaking so I'm pondering on replacing with either a Thomson or Race Face Diablus post because I'm fed up fettling with carbon paste, different clamps etc.

    enfht
    Free Member

    Well, it does take a finely honed mechanical sense to determine that without having a quick glance to check.

    Indeed

    wwaswas
    Full Member

    it coudl just be that the seat tube is slightly over/seatpost slightly under size.

    Ragley do a 27.3 seatpost now for just such occasions.

    Kieran
    Full Member

    Thomson – Light,

    I shall also use this in the BS of the week thread.

    In my experience they are. What's happened to this forum where you put your honest experiences and get shot down for your comments – at least substantiate your comment. I didn't realise the schools had broken up already?

    enfht
    Free Member

    Well said Keiran

    Thanks wwaswas I hadn't thought of that

    KINGTUT
    Free Member

    In my experience they are. What's happened to this forum where you put your honest experiences and get shot down for your comments – at least substantiate your comment. I didn't realise the schools had broken up already?

    Lighten up, Thomson Posts for e.g 27.2 x 410mm is 290g whilst it's not super heavy it's at least 50g or so above anything I'd consider, their stems are porky as well.

    FYI I left school 26 years ago.

    stanley
    Full Member

    If you are using a good quality post, then I don't think you need to worry about it snapping. However, creaking can be VERY frustrating.
    Are you sure it's the post ?
    From my experience it is usually either: the seatpost to seat-rail, seat-rail to seat, or seatpost to seat-tube interface.

    Maybe try stripping, cleaning and refitting them all ?

    Set back posts will (like for like) flex more too. I had an EA70, it flexed miles !
    Using Thomson's on all of the bikes now. They do flex (it adds comfort) but they aren't going to snap !

    (waits for some :-0 to say they snapped one !)

    clubber
    Free Member

    I bent one but it didn't snap 😉

    anotherdeadhero
    Free Member

    Thomson is great kit, but it sure ain't light. Well engineered kit that lasts, yes. Lightweight, only in comparision to scaff bar.

    People takes things awfully personally on here eh what?

    KINGTUT
    Free Member

    Well engineered kit that lasts

    The bolts on the seatposts aren't all that IMO.

    clubber
    Free Member

    Can't say I've ever had any issue with the bolts but then I don't reset my saddle every ride with a spirit level like you do KT…

    _tom_
    Free Member

    I've had no problems with the bolts on my Thomson either, and I do tend to crank down quite hard on these sorts of things.

    KINGTUT
    Free Member

    Can't say I've ever had any issue with the bolts but then I don't reset my saddle every ride with a spirit level like you do KT…

    True, over faffing and crappy tools probably did for them.

    anotherdeadhero
    Free Member

    The bolts on the seatposts aren't all that IMO.

    Is that becuase you've over torqued them to deal with your fat ass?

    I have had (counts quickly) 8 of them over the years, absolutely no issue. In fact I think thomson use some of the best fasteners I've ever had on bike kit, no corrosion issues, no binding, threads always run clean and true.

    KINGTUT
    Free Member

    Is that becuase you've over torqued them to deal with your fat ass?

    OMG TEH IRONING!!!!1111111111LOLLERCOPTERS.

    clubber
    Free Member

    FAOD FOAD

    anotherdeadhero
    Free Member

    *puts on his pinny*

    Potty mouth clubber

    Thomson posts have got the long axis of the internal ovalisation going across the bike.
    Does this mean they are intended to flex fore and aft, but not sideways ?

    stanley
    Full Member

    I don't understand KT's last response……………….

    …. but find it really funny 🙂

    Thanks, that's really made me chuckle 🙂

    clubber
    Free Member

    MilitantGraham – Member
    Thomson posts have got the long axis of the internal ovalisation going across the bike.
    Does this mean they are intended to flex fore and aft, but not sideways ?

    They're thicker front to back to make them stronger/stiffer in that direction and thinner side to side where they don't need to be so strong/stiff.

Viewing 40 posts - 1 through 40 (of 53 total)

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