Greater Manchester Marathon 2016
44 watchers
May 2016
3:20pm, 10 May 2016
46 posts
|
jennorocks
Oh an as someone how basically lives where all these are I'm gonna lose a lot of PBs. Almost every race I've every done is on here. Half PB is at cong, 10k is at salford, 5k is at congleton, 10 mile is at stockport. So thats all of them lol - not lol
|
May 2016
3:23pm, 10 May 2016
746 posts
|
larkim
Worrying that the measurement of the calibration distance seems to throw errors back to 2003 (though without remeasuring the courses as run, we'll never know 100% if the courses were short or not). Slightly surprising given how "accurate" the whole process is supposed to be (i.e. to 1/1000) that a calibration error of 0.5% gives varying errors ranging from 0.2% to 1%. That means that for the Trafford 10k course at least there are other errors in the measurement in addition to the calibration error. And if there are errors in that one which are not due to calibration, then surely just about every other measurement done by the course measurement officials should be considered to be likely to be inaccurate too? |
May 2016
3:26pm, 10 May 2016
5,594 posts
|
paul the builder
One source of error is going to be re-establishing a course some time after the event - trying to re-measure a course as it was actually run. So that's not a *real* source of error on the day itself.
|
|
May 2016
3:30pm, 10 May 2016
747 posts
|
larkim
True, that's why I suppose they've remeasured "active" races rather than done the others as that would be fraught with potential for error. Must admit though it's made me question whether I can ever believe the hype of the course measurement people about how accurate their systems and processes are with the spread of errors. If they were all consistent (with themselves, and with the Manchester error) that would be OK, but as they are all over the shop there is clearly something else going wrong and its possible that even they don't know what it is.
|
May 2016
3:32pm, 10 May 2016
3,262 posts
|
Nelly
larkim - have you read the specific report on the Trafford 10k? coursemeasurement.org.uk In particular the linked PDF measurement report which includes the following:- "Having raced the event myself, I am aware that runners do not follow the 30cm from the kerb rule and indeed on most of the route there is no defined kerb so I and the second rider kept close to the edge of the road at all times." From this I infer the Trafford 10k re-measurement took the shortest available route but the original measurement followed the rules, as mentioned by Old Croc on the GPS Errors thread, about staying a set distance inboard from the "kerb line". |
May 2016
3:36pm, 10 May 2016
12,802 posts
|
jennywren
That's what Dave Norman is saying. So if they remeasured using the original 30cm rule it would come out the same?
|
|
May 2016
3:38pm, 10 May 2016
3,263 posts
|
Nelly
I don't think so Jenny, I'd guess it would (or should) come out 0.5% short, i.e. the distance the calibration course is wrong.
|
May 2016
4:05pm, 10 May 2016
861 posts
|
jdarun
I doubt whether route choices can make much difference to the lenth. Pythagorus tells us that much. If you were zig-zagging as much as 5m from side to side every 100m then the extra distance would be about 0.1%. So long as you are reasonably close on the inside of corners and u-turns there won't be much extra distance, certainly nothing like 100m in a 10k.
|
|
May 2016
4:36pm, 10 May 2016
862 posts
|
jdarun
Furthermore, isn't it time to abandon poorly calibrated bicycle wheels and use laser rangefinders? They seem to claim precision of a fraction of a percent and would be much easier to calibrate and use reliably (though probably more effort and slower, would need two people moving alternately).
|
May 2016
4:56pm, 10 May 2016
1,102 posts
|
stuart little
Laser rangefinders? I'm sure local races have thousands of pounds available for accurate course surveys. Jones counters on bikes are highly accurate (i'm comfortable with a race accuracy of +/- 1m or so) it's human error that causes any issues |
Related Threads
-
Manchester Marathon 2021
Oct 2021
-
Greater Manchester Marathon 2020
Nov 2020
-
Manchester Marathon 2020 - Place Wanted
Aug 2019
-
Greater Manchester Marathon 2019
Aug 2019
-
Greater Manchester Marathon 2018
Apr 2018
-
Manchester Marathon Place For Sale
Nov 2017
-
Greater Manchester Marathon 2017
Apr 2017
-
Manchester Marathon place
Mar 2017
-
Manchester Marathon Discount code
Aug 2016
-
Greater Manchester Marathon 2015
Jul 2015