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  1. #1
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    Reputation: pmarshall's Avatar
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    Strava and gradient calculations?

    So I have been poking around the hills of Los Gatos and have come across some steep pitches of various lengths. Oh sorry, yeah on a skinny tire bike with super tight lycra on too! Anyway, this one particular segment has me asking what grade the road might or at least part of it? If I use Strava and slowly trace the segment, I see a high of 19% grade. The section that I trace when it says that is super steep! I mean steep!!! I am sure this section is only about 200 feet long and the rest of the road is in the 15% range. My basic math tells me it is calculated by Rise over Run. Here is the segment:


    Anybody around here ridden it and think that it could get that high?
    They never made the "Slowster"

  2. #2
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    I believe they calculate the grade as a percentage, so, 100x(rise/run), rather than an angle.

    Ive never ridden that particular road, but on a road bike I've climbed Joaquin, off the top of Alpine, and Redwood Gulch, off Stevens Canyon, both reach about 20% for bits and while they are steep, they're very doable.


  3. #3
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    Mr. Marshall: you, of all people—seeing as you are a fellow “serial masochist”—should know the steep from the not-so-steep. But you know how “accurate” our Garmins tend to be from day to day. Speaking of pain, you up for a Dogmeat no-dabs run sometime soon during the week?
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  4. #4
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    Garmin and Strava are like two teenage girls spreading rumors. By time the information gets transferred between each other, it's no longer true and completely outlandish.

    I love it when I upload my stuff to Garmin and I'm, like, "Yeah boy, 2000' of climbing biotch..."

    Then I upload to Strava and I get frowny face when it only reads, like, 1600' feet.

    I've seen some pretty weird grades, too. Yeah, when I was in junior high, but I'm talking about Strava. Strava claims Scenic Vista from Harry Rd. is only 10.3%. I say hell-to-the-no, but I guess they use averages. That shiz feels like 20% - what say you Leopoldo to the Porkstack Honey Brett Boo?

  5. #5
    Wēk Sôs
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    segment grade is from the endpoints, i believe.

  6. #6
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    Quote Originally Posted by Dion View Post
    Strava claims Scenic Vista from Harry Rd. is only 10.3%. I say hell-to-the-no, but I guess they use averages. That shiz feels like 20% - what say you Leopoldo to the Porkstack Honey Brett Boo?
    Dunno, haven’t ridden up it yet… at least, not that I can remember.
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  7. #7
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    IIRC Altitude is the most error prone calculation a GPS receiver makes and is subject to the greatest inaccuracy as well.
    Also I believe my garmin connect or strava accounts have an option to use table data for altitude instead of GPS calculated. Can't remember which choice I selected.
    Third, don't many of our cycle computers use barometric altitude measurements? I believe those need at least daily calibration.

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