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Confusion for a newbie.

  • 06-06-2013 10:51pm
    #1
    spoke2cun
    Registered Users, Registered Users 2 Posts: 448 ✭✭


    Sorry to bother you folks, but could do with a little bit of help regarding 2 topics. 1 is, how do you know what category you are in. 2 is, how do you calculate the percentage of a climb. Regarding 1, I have managed a 10 mile time trial in 28mins and regarding 2, would it be correct to say that a 1,500m long climb rising 150m would calculate as a 10% average gradient. Thanks.


Comments

  • #2
    HivemindXX
    Registered Users, Registered Users 2 Posts: 1,208 ✭✭✭HivemindXX


    Calculating the gradient is complicated by the fact that it is done differently depending on the purpose. I think you are correct for roads/cycling.
    http://en.wikipedia.org/wiki/Grade_(slope)

    No idea how you know what racing grade you are in apart from the obvious one of whether you are winning races or not.


  • #3
    joxerjohn
    Registered Users, Registered Users 2 Posts: 396 ✭✭joxerjohn


    Re the grade or slope, your calculation is not quite correct ! Given that LC maths paper 1 is on today here's a explanation.

    The gradient or slope calculation is the "rise over the run" expressed as a prevcentage.

    So if the rise was 150m and the run was 1500m then that equals 10%

    However the 1500m is the distance travelled up along the slope and not the run or horizontal distance travelled. You can of course work it out using trigonometry or by applying Pytagarus theory i.e. right angled triangles, (which should keep you quite for a while !).

    If you did this then the horizontal distance travelled would be 1492.5m.


    So the the slope would be 150/1492.5 = 10.05%, (not a big difference to your example).

    People often describe a steep hill as using a ratio e.g 1 in 5 which whould be the same as a 20% gradient. You might also see this ratio on road signs as well.

    Re you average speed for the 10 mile time trail = 21.4 mph or 34.3 kph which is good. The British 10 mile TT record is held by Michael Hutchinson (ASAIK) with a time of 17m.57s = equals 53.3 kph, so a ways to go yet !


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