[quote]requisite jaundice wrote:
Banked turns negate centripetal forces on curve running. The faster 200m tracks have hydraulically adjusted turns to optimize the angle. This is why Dempsey is slower than say, Arkansas or Boston for sprints. It also tends to negate the effects of more turns/mile.
Dempsey has long straights and narrow curves for its configuration. Several 200m tracks have similar turn radii to Dempsey, as well as the benefit of banking.
I have cited some prominent case histories above,and I have observed dozens more. When it comes to these things, times don't lie. The fact remains: the top athletes are running similar times at all quality venues, whether 300 unbanked, or 200 banked.[quote]
Neither Arkansas nor Boston are hydraulic. Arkansas is faster than Boston in the 200 and 400 because its finish line is at the end of the straightaway and allows the 200 and 400 runners to start at the highest point of banking and thus run down the bank immediately at the start. By contrast, the finish line in Boston is a bit more on the straight away, meaning that the sprinters start on a slightly lower part of the curve, have to run up the curve just a bit at the start, and have to run a little more curve on the first turn - three small items that result in a slightly slower time. Also, Arkansas is a firmer track, whereas Boston has a bit more bounce to it. This also tends to speed up the sprinter just a tad more.
To me, 5 laps to a mile is a grossly oversized track relative to indoor track and a small adjustment is warranted. By no means do I think that we're talking about a lot of time here. I'd say it's something in the order of .2 per curve. So, for a mile, I would compare the 16 turns on an 8 to a mile track to the 10 turn on a 5 to a mile track and cite a differential of 1.2 seconds, as there are 6 fewer turns.
Whenever you're running around a turn, you're running slower and further than you would if you were running on a straightaway. Therefore the more turn running in a race, the more of an adjustment should be made (understanding that 200 meter tracks are the standard).
On most 200 meter tracks you only get about 75 of straightaway per lap. In eight lap race, that's 600 meters of straightaway and 1000 meters of curves. On a 5 to a mile, you get about 180 meters of straightaway per lap, resulting in 900 meters of straightaway and 700 meters of curves. So, you can see that the oversized track provides a significant advantage, especially on long races. 5k on a 200 meter track is about 2k of straightaway and 3k of curves. 5k on a 5 to a mile track is 3k of straightaway and 2k of curves.
Let me ask you this, what do you think the time differential would be if a running raced 3k of curves versus 3k of straightaway? Also, keep in mind, that when the runner is in a curved race, he doesn't necessarily have the inner pole position - he will occasionally be in lane two or outside of lane one. On a straightaway a runner only covers the shortest possible distance.