Stem length?

snowster
snowster Posts: 490
edited January 2017 in MTB buying advice
Hi all when measuring your stem length from where do you take the measurements from?

Comments

  • fat daddy
    fat daddy Posts: 2,605
    centre of stem to centre of handlebar
  • snowster
    snowster Posts: 490
    fat daddy wrote:
    centre of stem to centre of handlebar
    So that's where the bolt holding down the stem to the forks i.e. Star nut to central handlebars?
  • fat daddy
    fat daddy Posts: 2,605
    correctamundo ...... although now I have said that I expect someone to pop up and say I have been doing it wrong all these years
  • snowster
    snowster Posts: 490
    Many thanks fat daddy if it's wrong I have now someone to blame :wink:
  • poah
    poah Posts: 3,369
    remember to go straight out if the stem has a rise.
  • snowster
    snowster Posts: 490
    Quick question what would happen if I increased the length of the stem from 100ml to 115ml how would this affect the handling of the bike?
  • The Rookie
    The Rookie Posts: 27,812
    The steering would be slower and more stable.

    You'd put more weight on the front wheel which improves front end grip.

    It would put your weight a long way forward on steeper descents which may not be as good.

    115 is very long for anywhere near approaching a modern MTB, in fact 100mm is pretty long
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • The Rookie wrote:
    The steering would be slower and more stable.

    You'd put more weight on the front wheel which improves front end grip.

    It would put your weight a long way forward on steeper descents which may not be as good.

    115 is very long for anywhere near approaching a modern MTB, in fact 100mm is pretty long

    Not necessarily.
    A longer stem on my hardtail made my bike much better in steeps, over dropoffs and big log rollovers because I could keep the bars out in front of me. With the stock stem it was easy in the steeps for my arms to be too bent and my weight overwhelm the strength of my arms and my body weight shift uncontrollably forward.
    So it depends on exactly where you are at the moment as to what will change.

    Same with bar height, counter intuitively, a lower stem can be better in the same steep conditions, as when you get far back behind the saddle, any forward force on your arms is acting on a shorter lever arm and you can also keep your whole body lower.
    This is the reason top XC riders run long and low.
    Their seat is full height for maximum efficiency and by running low and long they can tame the bike when things point downwards.
  • The Rookie
    The Rookie Posts: 27,812
    edited January 2017
    Makes no sense at all, push back on the bars with a shorter stem and your weight is further back, how you couldn't manage that I can't understand or begin to explain but everyone else seems to manage it just fine!

    XC riders run long and low for best pedalling efficiency!
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • rockmonkeysc
    rockmonkeysc Posts: 14,774
    Longer stem moves your weight forward which is not good for drops etc.