Can someone please resolve a dispute....
-
- Posts: 24
- Joined: Wed Dec 27, 2006 9:08 pm
- Location: Western burbs Adelaide
Can someone please resolve a dispute....
Postby Cluey » Mon Feb 19, 2007 7:42 pm
1 says...
If someone slips in behind you whilst pedalling not only does the follower 'slip stream' and therefore get an easier ride, but the rider in front does it a bit harder as they are 'carrying' the second rider...
2 says...
the second person just gets the slip stream benefit, the front rider experiences no difference in speed / effort / weight or whatever.
- AUbicycles
- Site Admin
- Posts: 15590
- Joined: Tue Aug 23, 2005 2:14 am
- Location: Sydney & Frankfurt
- Contact:
Postby AUbicycles » Mon Feb 19, 2007 8:01 pm
For larger vehicles, the effect of drag may be noticeable.
- sogood
- Posts: 17168
- Joined: Thu Aug 31, 2006 7:31 am
- Location: Sydney AU
Postby sogood » Mon Feb 19, 2007 8:50 pm
1) There's no single straight road that circles the planet.
2) The first rider couldn't even come close to Chris Hoy in terms of speed.
3) The first rider will burn up in a more spectacular fashion than Columbia over TX at that proposed speed.
RK wrote:And that is Wikipedia - I can write my own definition.
- europa
- Posts: 7334
- Joined: Sun Jul 16, 2006 10:51 am
- Location: southern end of Adelaide - home of hills, fixies and drop bears
Postby europa » Mon Feb 19, 2007 9:38 pm
On pushbikes, it's unlikely to be an issue (due to the lower speeds) and I've never heard a pro bike rider talk about it.
Richard
- mikesbytes
- Super Mod
- Posts: 22182
- Joined: Thu Dec 01, 2005 11:42 pm
- Location: Tempe, Sydney
- Contact:
Postby mikesbytes » Mon Feb 19, 2007 10:45 pm
Have a nice day
training log
- tuco
- Posts: 2016
- Joined: Wed Oct 11, 2006 3:36 pm
Re: Can someone please resolve a dispute....
Postby tuco » Mon Feb 19, 2007 10:49 pm
Actually it's number 3.Cluey wrote:I got two people having a little disagreement about....
1 says...
If someone slips in behind you whilst pedalling not only does the follower 'slip stream' and therefore get an easier ride, but the rider in front does it a bit harder as they are 'carrying' the second rider...
2 says...
the second person just gets the slip stream benefit, the front rider experiences no difference in speed / effort / weight or whatever.
The front rider does get a slight advantage. I was only reading about it yesterday. Something to do with the difference in air pressure behind the front rider when a rider is behind them. I didn't pay too much attention to the article as it wasn't what I was looking for so I just skimmed over it.
- Bnej
- Posts: 2880
- Joined: Fri Jun 30, 2006 11:43 pm
- Location: Katoomba, NSW
Postby Bnej » Mon Feb 19, 2007 11:04 pm
And there's drag as the vacuum behind you tries to suck you backwards.
Having someone directly behind you, I think, means that they are pulling the vacuum, while you are pushing the air to the sides and creating it. The front person does more work, but the net aerodynamic efficiency could improve for both.
- tuco
- Posts: 2016
- Joined: Wed Oct 11, 2006 3:36 pm
Postby tuco » Mon Feb 19, 2007 11:07 pm
In order to benefit from drafting, you've got to be in the drafting bubble behind the cyclist immediately in front of you. And in a crosswind the bubble will NOT be directly behind the rider in front but will be some angle away from them. The effectiveness of this bubble decreases with the distance, being the greatest if you draft closely and falling off until there is minimal benefit at 5 or 6 feet. The important fact is that you will get some benefit 3, or even 4 feet, back - and it’s a lot safer than being directly on the rear wheel of the rider in front of you.
The rider being drafted also gains a slight advantage. This is explained by the fact that the low pressure behind the lead rider is increased in a pace line, giving the leader a slight "nudge" due to the pressure differential between the high pressure ahead and the low pressure behind. This is why a NASCAR racing car will go 1-2 mph faster when being drafted.
http://www.cptips.com/energy.htm
- pospete
- Posts: 257
- Joined: Tue Feb 06, 2007 11:33 pm
- Location: Doncaster, Melbourne
Postby pospete » Wed Feb 21, 2007 3:33 pm
And there's drag as the vacuum behind you tries to suck you backwards.
Definatly cycling in Drag is best avoided, fishnets never look good on any bloke, and stilletoes were never designed for pedals either. I'll not even mention sucking anything whilst riding, it has just got to be dangerous
-
- Super Mod
- Posts: 1381
- Joined: Tue Sep 27, 2005 5:32 pm
Postby heavymetal » Wed Feb 21, 2007 5:07 pm
I found there wasn't much difference on the flat, but going up hill there was a noticable drag. Going downhill was another matter though, I could definately feel the benefit of having the BOB trailer behind me
_________________
How do I turn this stupid signature off?????
- tuco
- Posts: 2016
- Joined: Wed Oct 11, 2006 3:36 pm
Postby tuco » Wed Feb 21, 2007 5:16 pm
Drafting
Drafting is an important technique in road racing. Exploratorium Senior Scientist Paul Doherty explained, "The bicyclist, as he moves through the air, produces a turbulent wake behind himself. It makes vortices. The vortices actually make a low pressure area behind the bicyclist and an area of wind that moves along with the bicyclist. If you're a following a bicyclist and can move into the wind behind the front bicyclist, you can gain an advantage. The low pressure moves you forward and the eddies push you forward."
Suprisingly drafting not only helps the bicyclist following the leader, but the lead cyclist gains an advantage as well. Paul explained, "The interesting thing is by filling in her eddy you improve the front person's performance as well. So two people who are drafting can put out less energy than two individuals (who are not drafting) would covering the same distance in the same time." While the lead cyclist gains some advantage in this situation she still needs to expend much more energy than the cyclist who is following.
http://www.exploritorium.com/cycling/aerodynamics2.html
- Mr888
- Posts: 409
- Joined: Tue Jul 25, 2006 11:06 pm
- Location: Glenwood to Sydney CBD
Postby Mr888 » Wed Feb 21, 2007 7:03 pm
Do both the front and rear riders benifit from the tail wind or only the rear rider? Does it mean that the rear rider is breaking the wind push to the front rider?
If it's only benifiting the rear rider, then the front rider not only has to work twice as hard breaking the wind (excuse the pun) in front but also without the advantage of a helping tailwind that the rear rider is enjoying.
Therefore point 1 is correct...no?????
- mikesbytes
- Super Mod
- Posts: 22182
- Joined: Thu Dec 01, 2005 11:42 pm
- Location: Tempe, Sydney
- Contact:
Postby mikesbytes » Wed Feb 21, 2007 7:37 pm
Have a nice day
training log
- LuckyPierre
- Posts: 1432
- Joined: Fri Jul 14, 2006 4:37 pm
- Location: Canberra, ACT
Postby LuckyPierre » Wed Feb 21, 2007 8:11 pm
I've heard of lots of things, but no-one's even mentioned that breaking wind will help the rider in front of me!Mr888 wrote: Does it mean that the rear rider is breaking the wind push to the front rider?
- pospete
- Posts: 257
- Joined: Tue Feb 06, 2007 11:33 pm
- Location: Doncaster, Melbourne
Postby pospete » Wed Feb 21, 2007 9:05 pm
LuckyPierre wrote:I've heard of lots of things, but no-one's even mentioned that breaking wind will help the rider in front of me!Mr888 wrote: Does it mean that the rear rider is breaking the wind push to the front rider?
it would probably cause a stack up behind you tho!
- Mr888
- Posts: 409
- Joined: Tue Jul 25, 2006 11:06 pm
- Location: Glenwood to Sydney CBD
Postby Mr888 » Thu Feb 22, 2007 10:52 pm
But what happens when there's someone blocking that tail wind from behind? Wouldn't the front rider more or less still be pushing 40km/h? Does this mean that the rear rider is pushing less (due to drafting) but at the same time getting an extra 20km/h from the tail wind as well?...does anyone have a degree in physics here?mikesbytes wrote:Your assuming that the tail wind is actually stonger than the actual speed of the bikes, so if the bikes are doing 40kph, then the tail wind is stonger than 40kph. More likely the wind resistance has been reduced, A 20kph tail wind means that you are only pushing into the equivilant wind of 20kph when you are actually doing 40kph.
- Mr888
- Posts: 409
- Joined: Tue Jul 25, 2006 11:06 pm
- Location: Glenwood to Sydney CBD
Postby Mr888 » Thu Feb 22, 2007 10:54 pm
Best way to break wind is to stock up on some baked beans!LuckyPierre wrote:I've heard of lots of things, but no-one's even mentioned that breaking wind will help the rider in front of me!Mr888 wrote: Does it mean that the rear rider is breaking the wind push to the front rider?
- mikesbytes
- Super Mod
- Posts: 22182
- Joined: Thu Dec 01, 2005 11:42 pm
- Location: Tempe, Sydney
- Contact:
Postby mikesbytes » Thu Feb 22, 2007 10:59 pm
I think you missed the point. At 40kmh relative to the rider, a 15kmh tail wind is actually a 25kmh head wind, so the rider behind is not blocking that wind. The rider behind would be blocking the wind if you were riding at 10kmh with a 15kmh tail wind.Mr888 wrote:But what happens when there's someone blocking that tail wind from behind? Wouldn't the front rider more or less still be pushing 40km/h? Does this mean that the rear rider is pushing less (due to drafting) but at the same time getting an extra 20km/h from the tail wind as well?...does anyone have a degree in physics here?mikesbytes wrote:Your assuming that the tail wind is actually stonger than the actual speed of the bikes, so if the bikes are doing 40kph, then the tail wind is stonger than 40kph. More likely the wind resistance has been reduced, A 20kph tail wind means that you are only pushing into the equivilant wind of 20kph when you are actually doing 40kph.
BUT consider that at 40kmh in still air, that 80% of resistance is wind, then it is pretty unlikely that you will be riding slower than the tail wind.
Have a nice day
training log
- Mulger bill
- Super Mod
- Posts: 29060
- Joined: Sun Sep 24, 2006 2:41 pm
- Location: Sunbury Vic
Postby Mulger bill » Thu Feb 22, 2007 10:59 pm
Only HS sorry, and that was a while back.Mr888 wrote:But what happens when there's someone blocking that tail wind from behind? Wouldn't the front rider more or less still be pushing 40km/h? Does this mean that the rear rider is pushing less (due to drafting) but at the same time getting an extra 20km/h from the tail wind as well?...does anyone have a degree in physics here?mikesbytes wrote:Your assuming that the tail wind is actually stonger than the actual speed of the bikes, so if the bikes are doing 40kph, then the tail wind is stonger than 40kph. More likely the wind resistance has been reduced, A 20kph tail wind means that you are only pushing into the equivilant wind of 20kph when you are actually doing 40kph.
Isn't every rider pushing a bubble of air in front of him? Would No2s bubble be pushing the leader?
- pospete
- Posts: 257
- Joined: Tue Feb 06, 2007 11:33 pm
- Location: Doncaster, Melbourne
Postby pospete » Thu Feb 22, 2007 11:09 pm
Only HS sorry, and that was a while back.
Isn't every rider pushing a bubble of air in front of him? Would No2s bubble be pushing the leader?[/quote]
As we've allready discussed the theory behind breaking wind on riders behind you, I'll avoid the impracticalities of dropping a No2.
- Mr888
- Posts: 409
- Joined: Tue Jul 25, 2006 11:06 pm
- Location: Glenwood to Sydney CBD
- pospete
- Posts: 257
- Joined: Tue Feb 06, 2007 11:33 pm
- Location: Doncaster, Melbourne
Postby pospete » Thu Feb 22, 2007 11:32 pm
Mr888 wrote:Funny...I thought NO2 made you go faster...it did in "The fast and the Furious 1,2 & 3...."pospete wrote:
As we've allready discussed the theory behind breaking wind on riders behind you, I'll avoid the impracticalities of dropping a No2.
well if you guys want to go round dropping the no2s and using them to make yourselves go faster thats your own business. I have to say tho I'dd quite like to watch that bike race, if only to film it for You tube!
- Mr888
- Posts: 409
- Joined: Tue Jul 25, 2006 11:06 pm
- Location: Glenwood to Sydney CBD
Return to “General Cycling Discussion”
- General Australian Cycling Topics
- Info / announcements
- Buying a bike / parts
- General Cycling Discussion
- The Bike Shed
- Cycling Health
- Cycling Safety and Advocacy
- Women's Cycling
- Bike & Gear Reviews
- Cycling Trade
- Stolen Bikes
- Bicycle FAQs
- The Market Place
- Member to Member Bike and Gear Sales
- Want to Buy, Group Buy, Swap
- My Bikes or Gear Elsewhere
- Serious Biking
- Audax / Randonneuring
- Retro biking
- Commuting
- MTB
- Recumbents
- Fixed Gear/ Single Speed
- Track
- Electric Bicycles
- Cyclocross and Gravel Grinding
- Dragsters / Lowriders / Cruisers
- Children's Bikes
- Cargo Bikes and Utility Cycling
- Road Racing
- Road Biking
- Training
- Time Trial
- Triathlon
- International and National Tours and Events
- Cycle Touring
- Touring Australia
- Touring Overseas
- Touring Bikes and Equipment
- Australia
- Western Australia
- New South Wales
- Queensland
- South Australia
- Victoria
- ACT
- Tasmania
- Northern Territory
- Country & Regional
Who is online
Users browsing this forum: Amazon [Bot], Google Adsense [Bot], Majestic-12 [Bot], OnTrackZeD
- All times are UTC+10:00
- Top
- Delete cookies
About the Australian Cycling Forums
The Australian Cycling Forums is a welcoming community where you can ask questions and talk about the type of bikes and cycling topics you like.
Bicycles Network Australia
Forum Information
Connect with BNA
This website uses affiliate links to retail platforms including ebay, amazon, proviz and ribble.