Author Topic: Battle Mountain 2015  (Read 4957 times)

Re: Battle Mountain 2015
« Reply #25 on: September 19, 2015, 11:08:33 pm »
sorry, but naive question...

what's the deal about camera bikes as opposed to bikes that have a viewable window?
Is it...that it's just easier to build a faring where you don't have too worry about fabricating a see-through window that is also cleaning aerodynamic?

86.50mph...wow, that's now nearer 90mph than it is 80mph  :)
Garry Broad

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Re: Battle Mountain 2015
« Reply #26 on: September 19, 2015, 11:45:30 pm »
Cameras do make it easier to get a nice clean shape as the rider can be leaned further back.  Jan-Marcel says that in his riding position he'd only be able to see his knees.  As a bonus, the electronics enhance the view in low light such as we get when the evening sessions are running late.  Reliability and resolution are now both very good and if you're suitably clever you can overlay all sorts of information onto the basic view rather than just scrawling a list of target speeds on the inside of the windscreen with a crayon.  Todd is even monitoring CO2 levels :o
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Re: Battle Mountain 2015
« Reply #27 on: September 20, 2015, 08:26:05 am »
Just back in from the final evening runs and the awards bash.  Todd edged his world record out to 86.65 mph and Damjan finally got his 80 mph hat with an 80.01.  And then crashed Eivie 4.2 in what was apparently a deeply spectacular way.  He's OK but the bike is almost certainly a write-off.

Dave in the AR1 set a new BRITISH record with a 70.60, but it didn't last long before Ken trounced him with a 75.04.  Which puts BRITAIN ahead of Italy - since Andrea only managed a 72.19 tonight - and Australia (not playing this year).  Some of the Scousers would have been bouncing off the walls while still out in the desert if there were any but Dave and Ken both just told me they're too knackered to party any more.  Top work by the whole team to get the bike back together and running with the big boys.

My grate frend Jan-Marcel only managed a 76.49 tonight (cramp with two miles still to go) but still bagged third overall behind Todd and Damjan.  Erika says this is his fifth third in six years :-\

No photos from this evening uploaded yet coz I'm going to bed.
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ElyDave

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Re: Battle Mountain 2015
« Reply #28 on: September 20, 2015, 08:56:35 pm »
Some very fast times indeed, how long before they're closer to 100 than they are to 90?
“Procrastination is the thief of time, collar him.” –Charles Dickens

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Re: Battle Mountain 2015
« Reply #29 on: September 21, 2015, 01:50:11 am »
A minor correction, if I may be so bold; the Varna shape was subject to no computer refinement whatsoever.  Georgi Georgiev shaped them entirely by eye (he trained as a sculptor) and when the riders complained that they were too small he made them smaller ;D  Though something didn't go quite right with the Varna Battle Mountain as Barbara was always quicker in the slightly larger Tempest.  Also this year Aerovelo concentrated solely on Todd; Trefor Evans and Calvin Moes both rode it last year and while they're both quick they're not in the same league as Todd.

The Liverpool bike is a good deal bigger than Eta, albeit that Ken is also a good deal taller than Todd.  The Italian bike PulsaR is frikkin' huge by comparision.  Once the photos have finally gone up you'll be able to see what a tiny chap Andrea is...
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Re: Battle Mountain 2015
« Reply #30 on: September 21, 2015, 05:08:37 am »
A minor correction, if I may be so bold; the Varna shape was subject to no computer refinement whatsoever.  Georgi Georgiev shaped them entirely by eye (he trained as a sculptor) and when the riders complained that they were too small he made them smaller ;D  Though something didn't go quite right with the Varna Battle Mountain as Barbara was always quicker in the slightly larger Tempest.  Also this year Aerovelo concentrated solely on Todd; Trefor Evans and Calvin Moes both rode it last year and while they're both quick they're not in the same league as Todd.

The Liverpool bike is a good deal bigger than Eta, albeit that Ken is also a good deal taller than Todd.  The Italian bike PulsaR is frikkin' huge by comparision.  Once the photos have finally gone up you'll be able to see what a tiny chap Andrea is...

Edit: did you ever see such a sorry-looking bunch of crims in your life?


He's a villain, sir! by Mr Larrington, on Flickr

The ne'er-do-wells ticketed for exceeding the posted speed limit on Highway 305, for deviating from their travel lane1 or, in a few select cases, both.  L-R: Sergeant Arthur Aten of the Highway Patrol, Todd Reichert, Jan-Marcel van Dijken, Andrea Gallo, Damjan Zabovnik, Ken Buckley, Sherry Shi, Robert Braam, Lieske Yntema, Dave Collins.  Note extreme titchiness of Andrea (Jan-Marcel is about 6'3" long).

Clicky me for further Saturday pictures

1: i.e. crashing (falling over at the start doesn't count)
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Re: Battle Mountain 2015
« Reply #31 on: September 24, 2015, 05:06:52 am »
At the moment, I'd guess that Todd is putting out 450-500W for the last 30 seconds of his run - and timing that sprint correctly too - from a slow build at 250W. For a rider in the recumbent position, this is seriously world class. If Todd wanted to break 100mph, he'd need 750W for a significant length of time (i.e. longer than 5 secs). It doesn't look very likely: 150% of Saturday's performance.

The Scousers have put up the raw SRM data for Dave Collins' Saturday morning run: clicky.

The pretty output looks like this:



although the writing is probably too small to be of much use.
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Clare

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Re: Battle Mountain 2015
« Reply #32 on: September 24, 2015, 09:41:34 pm »
Mr Larrington, once again you have provided excellent reportage and given me a good few laughs  - thank you.


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Re: Battle Mountain 2015
« Reply #33 on: September 25, 2015, 12:35:03 am »
Thanks, I've picked that up. It's a shame that it's only Dave's 60mph Saturday morning run, but it presents some useful data.

I had a root around trying to find some decent local weather info, and it looks like the mornings in Nevada are bad for high speed racing (at least, that particular Saturday was), with cold, thick air - an air density of 1.2653 kg/m3 (typical UK conditions yield 1.21, and shortly before a thunderstorm broke over the Shaftesbury 50 a couple of years ago, I rode in air density of 1.16, the lowest I've ever measured/calculated (a 50-mile PB resulted  :) )). I also got the grade of the course from the recumbents forum (~0.5% at the traps).

Anyway, a nice build through 250-300W sees Dave get up to speed pretty quickly and then he clearly goes for it at the 6km mark, with an average 387W for the last minute and a 5-second peak around 424W just as he enters the traps.

Despite this, it's hard to gauge how aero their bike is - I'm having to make guesses about how much it weighs with a rider in it (I've had to make it 100kg to fit the speed/power), how lossy the crossover drive is (4%? an average TT bike is around 3%) and the fact that for this run they note they were using slower, more stable tyres (so a crr of 0.004, say, rather than 0.003 for nice radials - my best TT tyres are around 0.0035-0.004 too). Anyway, plugging all those numbers in gives a CdA of 0.029, which doesn't seem that amazing - maybe that camera bike estimate I got upthread was off the mark.

The Battle Mountain evenings are supposedly much better for speed: on that Saturday evening the air density dropped to 1.2085 kg/m3, which is a huge variation from the morning. Given the same ~400W output, Dave would go only 2mph faster in the evening, according to the calculations I'm using. I think that shows that for a slippery bike like this, air density is a factor, but nowhere near as much as it is for a draggy object like, say Bradley Wiggins on a track bike. This also explains how Todd was able to go so fast on his first record-breaking run, in the morning, and then only be able to add another mph in two subsequent evenings. I wasn't expecting that. Dave and Ken must've had a strong coffee or two before their evening 70 and 75mph runs (and I know from experience that most of us breathe more easily/put out more watts in warmer air).

[EDIT: in the same bike, Todd would need ~1000W to go 139km/h, but if Eta is only CdA 0.02, then a more believable 639W, that's still quite a lot, so maybe it's slipperier than that, or the online calculator I'm using is off.]

Elsewhere Damjan Zabovnik has posted that "CdA of Eivie IV is 0.0083m2.  I measure deceleration when I stop pedalling, taking into account Crr, air temperature, slope, mass. CdA can be extracted that way."  Mind you, that thing is tiny.
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Re: Battle Mountain 2015
« Reply #34 on: January 27, 2016, 12:03:10 pm »
It's just been pointed out elsewhere that claims on the BRITISH record by Messrs Buckley and Collins may be a bit previous chiz as Trefor Evans did 76.84 mph in Bluenose in 2013 and he has dual BRITISH/Canuckistani nationality.
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