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  • What difference would a 6 degree rise in stem make over 0 degrees in….
  • monksie
    Free Member

    ..reach? At the moment I have a 0 degree Deda Zero 110mm stem and the reach is fine but the height of the bars is a little too low. To counter this I’m eyeing up a new stem but I’m hesitating over what length. I’m sure 6 degree would be enough in height but obviously the same length stem (110mm) would shorten the reach.
    Is there a simple maths formula for geometry or a maths genius on here who can help?
    Basically, I’m trying to work out what length of stem I need to get the bars the same distance in reach but a touch higher.
    I don’t have the time funds or quite frankly patience to faff with different stems.
    Thanks

    clubber
    Free Member

    It’s negligible until you start going to 20+ degrees. Just stick with the same length.

    cynic-al
    Free Member

    To get the same horizontal dimension use 100*(cos 20/cos 26) = 104mm

    So a 100mm will be 4mm shorter and a 110mm 6mm longer than what you have now.

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    chiefgrooveguru
    Full Member

    Cos(angle)=A/H
    H=stem length
    A=reach
    A=H*cos(angle)=110xcos6=109.4mm

    Very much negligible! The six degree tilt will raise the bars by just over 11mm

    clubber
    Free Member

    It’s also worth adding that (at least in the past), some brands accounted for the difference due to angle so a 110mm stem was the same distance from steerer centre to h/bar centre regardless of the rise.

    monksie
    Free Member

    Cheers fella’s. Very helpfull

    cynic-al
    Free Member

    Ooops sorry I’d read 100 instead of 110 in your OP – add 10mm to my figures.

    It’s also worth adding that (at least in the past), some brands accounted for the difference due to angle so a 110mm stem was the same distance from steerer centre to h/bar centre regardless of the rise.

    You mean horizontally? Not heard of that before.

    Andituk
    Free Member

    Handy link..

    http://www.brightspoke.com/t/bike-stem-calculator.html

    Click on “Compare Two Stems” and enter the details.

    I did see a better one once that showed you as a graphic, but can’t find that one anymore.

    soobalias
    Free Member

    self moderated.

    clubber
    Free Member

    Al – yeah, can’t say I’ve heard about it for a while, hence the caveat but I definitely recall at least one company’s reps explaining about it which I guess really does make more sense even if the differences are negligible and people don’t really notice…

    chiefgrooveguru
    Full Member

    Cynic-al, did your calculation figure in the wotsit of the head angle (i.e. 90-70ish), hence the difference?

    monksie
    Free Member

    That website is top! Thank you.

Viewing 12 posts - 1 through 12 (of 12 total)

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