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Stack Height w/without spacers?

class5700class5700 Posts: 65
edited January 2015 in Road general
I am trying to gauge how different various bikes are to my own, in order to narrow down a suitable list of other bikes to try out. I have read that one of the main variables for assessing the size of frame and riding position is stack height.

so my question is whether stack height usually includes spacers and cone spacers. I assume it does not, and that the phrase 'slammed' refers to the removal of both cone and other spacers, so that stack height is purely a measurement of the frame and nothing else.

is this right?



  • Yes
  • nicklousenicklouse Posts: 81,520 Lives Here
    Stack height normally refers to the fitted height of components. Head tube length is normally stated.

    A headset stack height would include any spacers supplied as part of the headset. Ie a cone spacer top cover.

    Best to provide some links of what you are looking at so people can advise as to what info there is.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • imposter2.0imposter2.0 Posts: 11,234
    Head tube + headset stack height are the only fixed measurements - everything else is variable.
  • thanks for your replies.

    for example, this Tarmac is racier than my Trek 1.2 (perhaps too much so for me), but I want to see whether I should even bother taking a look at it.

    the stack for a 56cm frame is listed as 56.4cm: ... t#geometry

    while the specs indicate 20mm of spacers, with a 20mm cone spacer: ... port#specs

    so if the actual stack height of 56.4 is raised by 4 cm when the bike comes out of the factory, that's quite a difference, and would bring it much closer to my current bike.

    I'm assuming that the bike companies release their 'race' geometry bikes so that they appeal to the widest possible market.

    a lot of the 'endurance' frames I look at I feel are too filled with expensive suspension gadgets which I'm not sure I really want, so I've been looking at the options in the racier segment.
  • neebneeb Posts: 4,403
    FRAME stack height will be without spacers or headset cap. You could also specify a TOTAL stack height of a bike setup, which would take into account spacers, headset and stem (and the angles thereof, i.e. the vertical dIstance from the bb to a horizontal line through the centre of the bars), but if the stack height is quoted in relation to a frame rather than a bike, it should be excluding all spacers etc, i.e. the vertical distance from the bb to a horizontal line through the top of the headtube when the tubes are at their specified angles (which they should be when fitted with a fork of whatever is regarded as the standard length for that frame, i.e. these days the one that is upplied with it).
  • nicklousenicklouse Posts: 81,520 Lives Here
    As above.

    Some other reading viewtopic.php?t=12951776&p=18655853

    But also be careful when using info for different makers if they don't specify if it is a frame of bike measurement as I guess they will all measure to give themselves a perceived advantage over another brand.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • you need to be looking at stack in conjunction with reach; most manufacturers show these measurements and they are the best way of comparing framesize as they are measured from the BB. The numerical size of the frame is largely irrelevant and often misleading.
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