A MI measurer posed a question I've never heard nor contemplated: how do you measure stairs? I'm leaning toward having him use a steel tape, pulled taut across the edge of each step, from the bottom, upward.
Any other thoughts?
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The No Limits 10k at Alum Creek State Park (OH04053PR) is about 80 percent on pavement and 20 on a grassy dam top. Just after mile 4 the runners ascend 116 concrete steps for a total rise of 80 feet to the top of the dam.
When I measured the course I simply pushed the bike up the steps and later held it back as I went back down the steps.
I was using an electronic counter at the time and had a 3 meter difference out of about 35 meters each way up and down the stairs. The wheel was moving in a jerky manner and it was difficult to control, and I expect I got some double-counts. I used the lesser of the two measurements. The actual measurement path was a straight shot up or down the stairs, so it was not a question of being off the proper line.
Usually a flight of stairs represents a tiny fraction of the overall distance, so any inaccuracy in measurement will get lost in the overall total.
Using the bike is good enough. Taping is overkill.
When I measured the course I simply pushed the bike up the steps and later held it back as I went back down the steps.
I was using an electronic counter at the time and had a 3 meter difference out of about 35 meters each way up and down the stairs. The wheel was moving in a jerky manner and it was difficult to control, and I expect I got some double-counts. I used the lesser of the two measurements. The actual measurement path was a straight shot up or down the stairs, so it was not a question of being off the proper line.
Usually a flight of stairs represents a tiny fraction of the overall distance, so any inaccuracy in measurement will get lost in the overall total.
Using the bike is good enough. Taping is overkill.
Steps have been part of the course for some major races. The first 5-borough NYC Marathon encountered them near Gracie Mansion on the East River (that year the runners weren't allowed to run up 1st Ave.). And the Bonne Bell 10K in Boston, the all-women's event that has become the Tufts 10K, went up and down stairs on a pedestrian bridge along the Charles River.
I did a quick search and found values for a "typical" stair of 11x6.75 inches. With a 2.1 meter circumference tire, that would mean pushing your bike on the stairs would give a measurement of a little less than 1 inch per step greater than steel taping.
You could push your bike and then subtract this difference from your final number, but unless you have a lot of steps I wouldn't bother.
You could push your bike and then subtract this difference from your final number, but unless you have a lot of steps I wouldn't bother.
I got the same answer as Mark. 0.6 inches difference per step, with the bike giving the longer measurement.
Of course, there is the question of "What is the actual line that should be measured?" I leave this to the philosophers among us.
Of course, there is the question of "What is the actual line that should be measured?" I leave this to the philosophers among us.
Thanks fellows; I'm going to recommend the measurer walk his bike up/down the stairs.
Per Pete's question- there is no one answer that would sufficiently cover what line should be measured. A good argument could be made for measuring the diagonal w/a tape. But, if we're only losing about 1" per step walking the bike, that sits well too.
Per Pete's question- there is no one answer that would sufficiently cover what line should be measured. A good argument could be made for measuring the diagonal w/a tape. But, if we're only losing about 1" per step walking the bike, that sits well too.
Actually Pete, you got a different answer than me, but I had made a mistake and you are correct. About 0.6 inches/step.