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graydog
BHPC Member
Joined: 16 January 2006
Location: Wales
Status: Offline
Points: 1481
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Posted: 06 July 2006 at 6:51pm |
quote gNick:'OK graydog, you pay for the wind-tunnel time to get a realistic Cd for every member then... '
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ar who needs a wind tunnel with all the hot air flowing around here , and you are perhaps more correct CdA may be more apt... non the less you are a versed if not more so than I, in the experimental techniques as described by John Lafford amongst others. I must also say the same for Fish as T6 ‘top dog’.
However, as a newbee one sure fire way of ensuring we reduce rider numbers is to keep changing regs every other race or to leave uncertainty... how do you think the newbee is going to set thier path to the ‘Fish’ level if the first bike they buy, build or what ever fit no class next year?
Perhaps I did not explain me self correctly, using a speed or CdA system will not in anyway handy-cap any person after all you will still be running with the big boys. But in terms of forging innovation, to improve the bike around the rider using the CdA value allows for dynamic changes to the bike with out affecting the Cd coef thus allowing one to stay in the same class at faster speeds.
However, perhaps you are correct, conjecture over actual maybe the way to go after all you have been here longer than I as such I censed and should just watch…
I for one am still in limbo over my new bike, if the sports class (faired) is to run I have some changes. I would like to think it could fit the IHPV system as well as the Bhpc.
Very respectful
Graydog
Edited by graydog - 06 July 2006 at 6:53pm
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Rob
BHPC Member
Joined: 28 May 2005
Location: Derby
Status: Offline
Points: 1450
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Posted: 06 July 2006 at 7:06pm |
GeoffBird wrote:
What about us poor sods who spend hundreds of hours, in (often freezing cold) workshops, building machines that to some extent make up for our wholely inadequate athleticism? |
You've got a workshop! Tsk! I'm getting well pi**ed off with this "summer" weather where I'm trying to build and run a plastic forming oven in my back garden and it keeps getting rained on... A cold workshop, bah, luxury! Rob (4 weeks effort and no new fairing yet....)
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Rob, Westcountry Recumbents
http://www.wrhpv.com http://mullimages.com http://glydearoundbritain.blogspot.com
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Rob
BHPC Member
Joined: 28 May 2005
Location: Derby
Status: Offline
Points: 1450
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Posted: 06 July 2006 at 7:19pm |
graydog wrote:
Class one 'Bricks to Cd = 1' class X which is Cd=0.5 to Cd=0' setting say 4 classes in the range. |
Isn't a sphere worse than a brick? I seem to remember photos with lots of swirlly smokey bits behind the sphere... Rob
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Rob, Westcountry Recumbents
http://www.wrhpv.com http://mullimages.com http://glydearoundbritain.blogspot.com
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graydog
BHPC Member
Joined: 16 January 2006
Location: Wales
Status: Offline
Points: 1481
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Posted: 06 July 2006 at 8:03pm |
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but what of the leding edge, any way at .01mm they act pretty much the same as far as I know...
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GeoffBird
BHPC Member
Joined: 20 September 2005
Status: Offline
Points: 2396
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Posted: 06 July 2006 at 8:03pm |
Rob wrote: "You've got a workshop! Tsk!"
Did I say workshop? I meant cramped single garage, half-full of unecessary stuff like washing machines...
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Right Time - Right Place - Wrong Speed
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legs_larry
BHPC Member
Joined: 09 March 2005
Location: London Town Devine
Status: Offline
Points: 1554
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Posted: 07 July 2006 at 10:22am |
NickM wrote:
legs_larry wrote:
...stain-hiding undercoat applied to bedroom ceiling... |
This being a family forum, I won't ask how you managed to stain the bedroom ceiling...
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Dodgy flashing 'twixt tiles and chimbley-pot, courtesy of the Not-Quite-As-Phabulous-As-We-Thought-Phil, a Roofer of Essex.
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a bit ov a lyv wyr by slof standirds
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gNick
BHPC Member
Joined: 22 February 2005
Status: Offline
Points: 1977
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Posted: 07 July 2006 at 10:33am |
And he does mean cramped - more free space inside the Fish when I'm in it IIRC.
The problem with DIY tests for CdA and the like is that there are too many variables in roll-down type tests. These can make consecutive tests variable, let alone ones in different places and weather conditions.
It has to be said that there are no universally accepted classes, we all seem to run to a slightly different idea. That said the splitting of our Unfaired class into Naked and Partially Faired does cover all bases. A few of us are trying to get some kind of universality at least across Europe but HPV people are remarkably anarchistic!
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gNick
"I'm afraid it's definite, Mrs Banker - your son has bicycles"
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graydog
BHPC Member
Joined: 16 January 2006
Location: Wales
Status: Offline
Points: 1481
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Posted: 07 July 2006 at 10:44am |
Thanks gNick, and it is true experimental data can led to variability, one day I hope to pitch against you and the fish, it seems the ultimate speed meets technology in one (it goes for all streamers).
No matter what you 'DE management' do there will alway be "why can't we have" situation, so I thank you and wish you all the best in this task.
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gNick
BHPC Member
Joined: 22 February 2005
Status: Offline
Points: 1977
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Posted: 07 July 2006 at 11:11am |
Since all seems clear as mud here is a simple view of the BHPC class structure - at least I think so but I am the Missing Link(tm) so what so I know? A diagram is called for I fear - I will try to do one when they take the straitjacket off.
There are 2 sorts of class, I will call them Primary and Specific because I think they should have a name that fits my description.
The Primary classes can be visualised as a table with 3 columns and 3 rows: the whole table is Open, the 3 vertical columns are Men, Women and Juniors and the 3 rows are Faired, Partially Faired and Unfaired.
Vertically, the Men division isn't used, the competitors being in just in Open and likewise horizontally the Faired class isn't used and the competitors are in Open, though, if appropriate the gender division applies. So a fully faired male is just in the Open class and a fully faired Junior is in Open and Junior Open.
The Specific classes are ones for a particular subset of machines, so Sports and Multitrack can be from Unfaired and Partially faired; Multitrack from Unfaired and Partially faired, Velomobile and Street are a subset of Faired and Armpowered is a subset of Open.
Coming soon at a recumbent club near you - the HPV caste system...
Edited by gNick - 07 July 2006 at 1:07pm
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gNick
"I'm afraid it's definite, Mrs Banker - your son has bicycles"
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GeoffBird
BHPC Member
Joined: 20 September 2005
Status: Offline
Points: 2396
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Posted: 07 July 2006 at 11:21am |
This gets more like "I'm Sorry I Haven't a Clue" every minute!
Kudos to gNick for trying to get his head round it...
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Right Time - Right Place - Wrong Speed
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