Author Topic: PBP 2019 - Notes to self  (Read 10635 times)

Re: PBP 2019 - Notes to self
« Reply #125 on: September 15, 2019, 11:46:53 am »
Thought I'd see what like if the average for the 90hr was a steady 13.3


Standard Route            km   Steady Close       Real Close         My time            Stdy IH    Real IH
RAMBOUILLET                0   18/08/2019 18:30   18/08/2019 18:30   18/08/2019 18:36      
Mortagne-au-Perche       118   19/08/2019 03:21   19/08/2019 02:22   18/08/2019 23:13   04:08:00   03:09:00
VILLAINES-LA-JUHEL       217   19/08/2019 10:46   19/08/2019 08:58   19/08/2019 04:22   06:24:23   04:35:53
FOUGERES                 306   19/08/2019 17:27   19/08/2019 14:54   19/08/2019 10:13   07:13:42   04:40:42
TINTENIAC                360   19/08/2019 21:30   19/08/2019 18:45   19/08/2019 14:11   07:18:38   04:33:38
Quédillac                386   19/08/2019 23:27   19/08/2019 20:36   19/08/2019 15:53   07:34:00   04:43:00
LOUDEAC                  445   20/08/2019 03:52   20/08/2019 00:49   19/08/2019 19:49   08:03:04   04:59:34
Saint-Nicolas-du-Pélem   488   20/08/2019 07:06   20/08/2019 03:56   19/08/2019 22:53   08:13:00   05:03:00
CARHAIX-PLOUGUER         521   20/08/2019 09:34   20/08/2019 06:15   20/08/2019 01:26   08:08:02   04:48:32
BREST                    610   20/08/2019 16:15   20/08/2019 12:36   20/08/2019 08:51   07:23:26   03:44:26
CARHAIX-PLOUGUER         693   20/08/2019 22:28   20/08/2019 18:34   20/08/2019 15:06   07:22:15   03:27:45
Saint-Nicolas-du-Pélem   738   21/08/2019 01:51   20/08/2019 21:57   20/08/2019 18:05   07:46:00   03:52:00
LOUDEAC                  783   21/08/2019 05:13   21/08/2019 01:23   20/08/2019 21:07   08:05:48   04:15:18
Quédillac                843   21/08/2019 09:43   21/08/2019 05:59   20/08/2019 02:26   07:17:30   03:33:00
TINTENIAC                869   21/08/2019 11:40   21/08/2019 08:02   20/08/2019 03:45   07:55:03   04:16:33
FOUGERES                 923   21/08/2019 15:43   21/08/2019 12:11   20/08/2019 09:43   05:59:32   02:27:02
VILLAINES-LA-JUHEL      1012   21/08/2019 22:24   21/08/2019 19:16   20/08/2019 17:03   05:20:05   02:12:05
MORTAGNE-AU-PERCHE      1097   22/08/2019 04:46   22/08/2019 02:18   20/08/2019 22:43   06:02:46   03:34:16
DREUX                   1174   22/08/2019 10:33   22/08/2019 08:46   20/08/2019 05:12   05:20:04   03:33:04
RAMBOUILLET             1200   22/08/2019 12:30   22/08/2019 12:30   20/08/2019 09:08   03:21:21   03:21:21


It's quite a striking difference;

Trouble is you would need to use an average minimum speed of about 13.6 km/h for the 90 hours to allow for the extra distance that ACP don’t give you extra time for, otherwise you could have an impossible task from Dreux to the finish. This is also a common problem with over distance BRM events in the UK too.


FifeingEejit

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Re: PBP 2019 - Notes to self
« Reply #126 on: September 15, 2019, 12:01:15 pm »
My understanding of the way the timings work normally is that the over distance doesn't count so the 13.3 average sticks until the last section where it kicks in, or in other words as far as the timings are concerned ramboulliet is on 1200km.
That's why on that table I've put ramboulliet at 1200.

Despite the published distance being 1219 this year I've recorded 1225km, thee equired on the road average can be very different from the nominal!

The advantage of the loaded timings is that it does allow the organizer to hide the impact of the over distance section in the last leg.

The timings I posted previously gave the average speed required on the section between dreux and ramboulliet for the full 1219km advertised.

Sent from my BKL-L09 using Tapatalk

Phil W

Re: PBP 2019 - Notes to self
« Reply #127 on: September 15, 2019, 02:11:30 pm »
Don't forget you had a diversion on the last leg, due to roadworks, which may have also added some km.

FifeingEejit

  • Not Small
Re: PBP 2019 - Notes to self
« Reply #128 on: September 15, 2019, 03:22:48 pm »
Don't forget you had a diversion on the last leg, due to roadworks, which may have also added some km.

I got 43.8km for that leg (as does he altered official gps); the original route was just over 44km judging from WilkyBoy's route and the distance noted in the dosier.

Phil W

Re: PBP 2019 - Notes to self
« Reply #129 on: September 15, 2019, 03:40:03 pm »
Ahhh ok. I've also worked out that if you did on average an extra 353 metres of travel within each control that's your 6km.

FifeingEejit

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Re: PBP 2019 - Notes to self
« Reply #130 on: September 15, 2019, 04:43:15 pm »
Ahhh ok. I've also worked out that if you did on average an extra 353 metres of travel within each control that's your 6km.

Yeah, there's also cases where I've gone a wee bit up a side road for a comfort break as well, wrong turns, gps wobbles etc.

Looking again you can see the impact of the loadings and the overdistance
On the Steady time there is only 1hr 57m to do the 45km from Dreux to Ramboulliet due to it being 26ACPKm
On the Loaded timings there is 3hrs 14m to do the 45km





Re: PBP 2019 - Notes to self
« Reply #131 on: September 15, 2019, 06:26:09 pm »
My understanding of the way the timings work normally is that the over distance doesn't count so the 13.3 average sticks until the last section where it kicks in, or in other words as far as the timings are concerned ramboulliet is on 1200km.
That's why on that table I've put ramboulliet at 1200.

Despite the published distance being 1219 this year I've recorded 1225km, thee equired on the road average can be very different from the nominal!

The advantage of the loaded timings is that it does allow the organizer to hide the impact of the over distance section in the last leg.

The timings I posted previously gave the average speed required on the section between dreux and ramboulliet for the full 1219km advertised.

Sent from my BKL-L09 using Tapatalk
That could be resolved as follows
All controls up to Brest average speed 15kmh. (should be achievable as everyone has hit these limits on their SR series.
90 hours to the finish. Work backwards from Rambouillet deducting time equivalent to 13.33 km  so the over distance is lost in the step change at 600km. This way no one has an impossible last leg, but neither is a ridiculously generous 17hours allotted for the last 200km

Eddington  96miles

Re: PBP 2019 - Notes to self
« Reply #132 on: September 15, 2019, 08:12:16 pm »
That could be resolved as follows
All controls up to Brest average speed 15kmh. (should be achievable as everyone has hit these limits on their SR series.
90 hours to the finish. Work backwards from Rambouillet deducting time equivalent to 13.33 km  so the over distance is lost in the step change at 600km. This way no one has an impossible last leg, but neither is a ridiculously generous 17hours allotted for the last 200km

Or do it the way that they currently kind of do it (give or take a bit):-

https://yacf.co.uk/forum/index.php?topic=113068.msg2420241#msg2420241

(The first 300km assumes 15kph and then the rest of the ride is pro-rata remaining time limit over remaining distance, so that the over-distance aspect does not suddenly become a problem at any point.)
"Yes please" said Squirrel "biscuits are our favourite things."

Re: PBP 2019 - Notes to self
« Reply #133 on: September 15, 2019, 08:41:33 pm »
I suppose my note to self would have to be 'don't break ankle 5 weeks before the event'. 

I got as far as Loudeac. 

I have some very fine friends indeed. 

Re: PBP 2019 - Notes to self
« Reply #134 on: September 15, 2019, 11:26:50 pm »
That could be resolved as follows
All controls up to Brest average speed 15kmh. (should be achievable as everyone has hit these limits on their SR series.
90 hours to the finish. Work backwards from Rambouillet deducting time equivalent to 13.33 km  so the over distance is lost in the step change at 600km. This way no one has an impossible last leg, but neither is a ridiculously generous 17hours allotted for the last 200km

Or do it the way that they currently kind of do it (give or take a bit):-

https://yacf.co.uk/forum/index.php?topic=113068.msg2420241#msg2420241

(The first 300km assumes 15kph and then the rest of the ride is pro-rata remaining time limit over remaining distance, so that the over-distance aspect does not suddenly become a problem at any point.)
I can’t see the point of making it so complicated. A rider travelling at the actual minimum average speed required to complete the actual distance of the event for their chosen start group would arrive on time, so why make it more difficult for them by requiring faster minimum speeds at the intermediate controls?

This year I clocked up 1223.6 km which means the average speed required for 90 hours was about 13.6 km/h. If this was applied throughout the event, each 200 km would need to be covered in 14 hours 42 minutes, so not a ridiculously long time in my opinion.

I think most of us had a headwind most of the way out this time, and although it was tough it could have been a much stronger wind, and that’s when a constant minimum average speed for the whole event would help a lot of riders.


FifeingEejit

  • Not Small
Re: PBP 2019 - Notes to self
« Reply #135 on: September 15, 2019, 11:49:29 pm »
The problem is if you apply standard BRM rules, you have to average 22kmh between dreux and ramboulliet if you leave dreux on the time limit...

The loading protects you from that rude awakening

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Re: PBP 2019 - Notes to self
« Reply #136 on: September 16, 2019, 11:14:43 am »
The problem is if you apply standard BRM rules, you have to average 22kmh between dreux and ramboulliet if you leave dreux on the time limit...

The loading protects you from that rude awakening

The loading itself doesn't protect you from that.

They are two different things.

First of all, as you say, the ride is over distance, so if you do 13.3kph for 90 hours you end up some 25km short of the finish of a 1225km event. SR Steve's suggestion is to just use ~13.6kph (actual ride distance / 90h) as the minimum average speed for the whole event so there is no front loading required and the minimum average speed is flat over the entire ride and the last control times aren't shortened. But ACP/BRM rides do not do this.

The completely separate thing is why ACP/BRM rides "front load" rides with increased average speeds in the earlier stages and then lower average speeds later on.

Article 10 here goes into the basic BRM rules for closing times: http://www.audax-club-parisien.com/EN/312%20-%20Rules%20of%20BRM%20France.html

Quote
Additionally, riders must arrive at each checkpoint between the opening and closing time for the checkpoint and calculated as follows:
Opening: 34 km / h (km 1 to 200); 32 km / h (km 201 to 400); 30 km / h (km 401 to 600); 28 km / h (km 601 to 1000); commercial rounded by the minute.
Closing: 1 hour + 20 km / h (km 1 to 60); 15 km / h (km 61 to 600); 11.428 km / h (km 601 to 1000); commercial rounded by the minute.

Of course, this still doesn't cover everything exactly as it would put the closing time for a control at 400km at 26h40 despite the official time limit for a 400 being set at 27h (14.815kph). Audax is more a list of exceptions to rules than rules themselves.

These figures also don't match the control closing times in PBP, I've no idea exactly what formula they use there but my best guess is in the thread I linked earlier.

The question is why BRM/ACP front load the controls so much, and my guess is that it's designed to make people who are going to fail to finish give up earlier in the ride and therefore be less of a danger to themselves and others by pushing on for longer than they should.

Taking an easy example, Brest is halfway through the ride and therefore a flat average speed would give 45h to get there. If a typical rider just scrapes in to Brest in 44h58m then with just a couple of minutes faffing they'll be in a position where they'll need to completely the second half of the ride faster than they completed the first, which is highly unlikely with an extra 600km in their legs. By forcing them to get there in 43h or so they're guaranteed to have some time in hand on a flat schedule - they could rest for 3 hours and still have more time to finish than they'd taken so far.

Using an argument of extremes, giving people up until 89h to get to Brest would be silly, as that would probably lead to a greater DNF rate than normal as people took too long over the first half. Similarly, only giving people 24h to get to Brest would lead to a huge DNF rate (if the intermediate control closing times were enforced). Therefore the sensible point is somewhere in between these two extremes. I'd guess that ACP believe that it is best set lower than 45h but above 40h and so they've settled on whatever they use now. Setting it at 45h or above does not make sense as the majority of people are not going to be negative splitting PBP.
"Yes please" said Squirrel "biscuits are our favourite things."

Re: PBP 2019 - Notes to self
« Reply #137 on: September 16, 2019, 11:19:59 am »
When I got my card on the Sat, it was obvious that the closing times were not personalised, and were the final closing time for the last group, so not correct for me.
So I wrote my own closing time in small writing at the bottom of each box just for my information.
( I didn't scribble over the printed times, I left those alone. )

I had most of Saturday to do this, so it was no biggie.

No-one complained about this.
... or adjust your watch to PBP time

FifeingEejit

  • Not Small
Re: PBP 2019 - Notes to self
« Reply #138 on: September 16, 2019, 12:39:11 pm »
... or adjust your watch to PBP time

Wonder how many riders had settable watches, I know a couple who did, but I left my trusty Casio fw91 at home in favour of relying on my gps clock...
(I also left my considerably less trusty Garmin Fenix2 at home because I wasn't expecting to do any walking/hiking/running)

TOBY

  • hello
Re: PBP 2019 - Notes to self
« Reply #139 on: September 16, 2019, 01:15:26 pm »
You couldn't trust the clocks at the controls, I didn't see one that wasn't 1 hour fast

dubya

  • You can't stop the waves,but you can learn to surf
Re: PBP 2019 - Notes to self
« Reply #140 on: September 16, 2019, 02:11:22 pm »
You couldn't trust the clocks at the controls, I didn't see one that wasn't 1 hour fast

marcusjb

  • Full of bon courage.
    • Occasional wittering
Re: PBP 2019 - Notes to self
« Reply #141 on: September 16, 2019, 03:40:07 pm »
You couldn't trust the clocks at the controls, I didn't see one that wasn't 1 hour fast

[gammon]
Indeed; a great example of an area where LEL's organisation is out-performing PBP's.
[/gammon]
Right! What's next?

Ooooh. That sounds like a daft idea.  I am in!

FifeingEejit

  • Not Small
Re: PBP 2019 - Notes to self
« Reply #142 on: September 16, 2019, 04:02:42 pm »
They might be 2 hours fast come 2023 depending on whether the french choose permanent CET or CEST, although their natural times zone would be WET/WEST

Re: PBP 2019 - Notes to self
« Reply #143 on: September 16, 2019, 05:35:10 pm »
You couldn't trust the clocks at the controls, I didn't see one that wasn't 1 hour fast

[gammon]
Indeed; a great example of an area where LEL's organisation is out-performing PBP's.
[/gammon]

We've got 6 LEL clocks in our house, as well as 6 laptops and 6 bar-code readers. The barcode readers don't get much of an outing. 3 laptops made it to PBP, along with 3 batteries from the other 'puters'. The clocks make it out into the real world occasionally. https://youtu.be/xk8Xxd9Ro4Y?t=160

I tend to view Audax, and PBP especially, as an example of the Hawthorne Effect. https://en.wikipedia.org/wiki/Hawthorne_effect
Participants are motivated by being observed, and the more they believe in that, the harder they try. The cutoff times are useful in that they give the impression of a deadline, that has to be adhered to. If you remove the belief that the control staff will take your card away if you are late, the power of the Hawthorne Effect is diminished. The idea of an impartial and external validation is integral to the endeavour.

The reality is more like The Wizard of Oz.