Building fairings
- Thread starter Lowell
- Start date
Lowell:
thanks, my daily ride gets the business done, well daily. "A Smooth Ride for a Rough World"
Fechter: Good question. How much area, in what position(fore/aft up/down) in what shape?
I know that you have Lid that you dieing to try out. Don't think Twice, Hell you're already a Nerd.(I assume, since you are on this board).
knoxie: "I'm thinking it prob makes you less efficient though?"
No, not at all, you get the advantage of the tuck without tucking. And if you did tuck behind the RRF......
"Bents" don't cut it for me, I want to see, to SEE the way people get to see up in an SUV.
I just want to get to the good beer on the batteries I already own.
Perhaps a "power multiplication device".
Tyler:
Thanks.
@ 20 mph I only saw an 8-9% improvement, But with a little work, maybe 20% is possible. This is pretty crude, but with real results. The difference in power needed to go 25 mph verus 32 mph is something like 450 watts. Can this be true? It's from: http://www.kreuzotter.de/english/espeed.htm : "hands on the tops" 438 watts@ 24.6--- 'hands on the tops" 896 watts@ 32 mph.
Someone check my calc's & logic, please.
Oh and here is an unintended consequence, Longer Stopping Distances without the aero drag, also brake pads will wear faster. Can't have the Yin without the Yang.
Did anyone notice the "Aero discs" on the Type5MilitaryPoliceBike?
One thing worth mentioning is how much easier it is to maintain 20mph with peddling only.
You can coast much farther.
Motor on or not, you're still getting the advantage.
Later
Kyle
thanks, my daily ride gets the business done, well daily. "A Smooth Ride for a Rough World"
Fechter: Good question. How much area, in what position(fore/aft up/down) in what shape?
I know that you have Lid that you dieing to try out. Don't think Twice, Hell you're already a Nerd.(I assume, since you are on this board).
knoxie: "I'm thinking it prob makes you less efficient though?"
No, not at all, you get the advantage of the tuck without tucking. And if you did tuck behind the RRF......
"Bents" don't cut it for me, I want to see, to SEE the way people get to see up in an SUV.
I just want to get to the good beer on the batteries I already own.
Perhaps a "power multiplication device".
Tyler:
Thanks.
@ 20 mph I only saw an 8-9% improvement, But with a little work, maybe 20% is possible. This is pretty crude, but with real results. The difference in power needed to go 25 mph verus 32 mph is something like 450 watts. Can this be true? It's from: http://www.kreuzotter.de/english/espeed.htm : "hands on the tops" 438 watts@ 24.6--- 'hands on the tops" 896 watts@ 32 mph.
Someone check my calc's & logic, please.
Oh and here is an unintended consequence, Longer Stopping Distances without the aero drag, also brake pads will wear faster. Can't have the Yin without the Yang.
Did anyone notice the "Aero discs" on the Type5MilitaryPoliceBike?
One thing worth mentioning is how much easier it is to maintain 20mph with peddling only.
You can coast much farther.
Motor on or not, you're still getting the advantage.
Later
Kyle
"Oh and here is an unintended consequence, Longer Stopping Distances without the aero drag, also brake pads will wear faster. Can't have the Yin without the Yang."
That's something I hate about bent bikes, no air brakes. Notice how motorcycle racers sit straight upright under braking, it makes a big difference.
That's something I hate about bent bikes, no air brakes. Notice how motorcycle racers sit straight upright under braking, it makes a big difference.
Yo Lowell
You really hate bents dont you? you must try one it will change your outlook on everything, there is a lot more to cycling than upright bikes and none geared motors, you must try them before you decry them!! thats a slogan in one! :lol: no really old friend you must, my point still stands, my KMX is much more efficient in drag terms than any upright bike with a fairing, I know this from charging around with my meters strapped in.
Its very hard to make an upright bike efficient in this way without it looking dorky and cumbersome, besides that for true efficiency using the online calc at kreutzer its plain and simple that a bent is the most efficient as far as that is concerned.
TDF Cyclists are very efficient using super light bikes, wearing lycra and cycling tucked in and tight, this may be the best option with a nice light A123 pack on your back and a super efficient BLDC motor in the 700 wheel!! I have seen something on youtube like that!!
We can argue geared vs none geared all night etc etc, what ever you want what ever you like
Knoxie
You really hate bents dont you? you must try one it will change your outlook on everything, there is a lot more to cycling than upright bikes and none geared motors, you must try them before you decry them!! thats a slogan in one! :lol: no really old friend you must, my point still stands, my KMX is much more efficient in drag terms than any upright bike with a fairing, I know this from charging around with my meters strapped in.
Its very hard to make an upright bike efficient in this way without it looking dorky and cumbersome, besides that for true efficiency using the online calc at kreutzer its plain and simple that a bent is the most efficient as far as that is concerned.
TDF Cyclists are very efficient using super light bikes, wearing lycra and cycling tucked in and tight, this may be the best option with a nice light A123 pack on your back and a super efficient BLDC motor in the 700 wheel!! I have seen something on youtube like that!!
We can argue geared vs none geared all night etc etc, what ever you want what ever you like
Knoxie
I've tried various flavors of non assisted two and three wheeled recumbents, and if I lived in a rural area with a long, traffic free commute I would probably have a tadpole somewhere in the garage. I'd like to see some hard numbers for braking distance and cornering force on bent bikes compared to uprights. I like the maximum overall performance envelope, and 2 wheeled machines already give up some braking ability compared to what I'm used to. (my car has 355x32mm rotors with massive radial mount 4 piston calipers) I would not want any less braking ability than a well set up upright bike that can unload the rear wheel.
Despite running both my headlights on full power 100% of the time (bright even in directly sunlight) I still get cars trying to turn left in front of me, and the occasional idiot trying to take my lane. No different from a motorcycle actually, and I'm sure it would be much worse if I was sitting on the ground.
Despite running both my headlights on full power 100% of the time (bright even in directly sunlight) I still get cars trying to turn left in front of me, and the occasional idiot trying to take my lane. No different from a motorcycle actually, and I'm sure it would be much worse if I was sitting on the ground.
knoxie: "for true efficiency using the online calc at kreutzer its plain and simple that a bent is the most efficient as far as that is concerned. "
There must be something to the 'Bents, but it doesn't seem to show in the simulators:
http://www.kreuzotter.de/english/espeed.htm
rider height 5'9"
rieder wight 185
Bike weight: 60
Racing bikes: Effective Drag Area
hands on the tops: 5.13 sq. ft.
hands on the drops: 3.46 sq. ft.
tri bike: 2.89 sq. ft.
superman position: 2.18 sq. ft.
Recumbents: Effective Drag Area
LoneWheelBase: 4.62 sq. ft.
ShortWheelBase1: 3.57 sq. ft.
ShortWheelBase2: 2.33 sq. ft.
Streamline Lowracer: 0.32 sq. ft. (world record holder) This must be some ride.
I don't get it!
Except for the Uber "Streamline Lowracer" the numbers for 'Bent's aren't really all that great. "Hands on the drops" rate as well as the "ShortWheelBase1"recumbent.
I must be missing something.
The numbers I'm seeing from a MTB with a garbage can lid are in the "superman" range, better than a "ShortWheelBase2" recumbent.
What am I missing?
No Doubt the RRF is definitely dorky
, but cumbersome, not really.
"for true efficiency using the online calc at kreutzer its plain and simple", Yes, it seems to be simple, there isn't really that much difference and what there is, doesn't favor a 'Bent.(Well, a 'Bent has to be better on the Butt.)
I mean talk about "looking dorky and cumbersome", that really fits a 'Bent to a "T".
You know, what got me going on this is that I want to go 25 miles @ 25 mph, Seems reasonable. I'm sitting at 18 miles @ 18 mph right now. But to go from 20 mph to 25 mph means you basically have to double the battery pack, and more miles, more batteries yet.
Well, instead of just buying more batteries, I'm looking for efficiencies that I have overlooked or don't understand.
And there is a lot I don't understand about both the components and the entire system. For example, the 4011 of my 408/4011 is a bit slower, but quite a bit more efficient. For example, putting a garbage can lid in front of you makes you 10%-30% more efficient.
A dime here, a dime there....
My point is to look at the variety of things that can be easily improved, not perfected with Lycra, for the most gain to the whole. Great efficient in one area means nothing unless the other 6 or 8 areas are also at some degree of efficiency too.
It's the whole that we ride.
"what ever you want what ever you like ", that's exactly why there are so many different tasting beers, so many different tastes.
Personally, I favor a strong IPA, but after mowing the lawn, a Bud is just fine.
Later
Kyle
There must be something to the 'Bents, but it doesn't seem to show in the simulators:
http://www.kreuzotter.de/english/espeed.htm
rider height 5'9"
rieder wight 185
Bike weight: 60
Racing bikes: Effective Drag Area
hands on the tops: 5.13 sq. ft.
hands on the drops: 3.46 sq. ft.
tri bike: 2.89 sq. ft.
superman position: 2.18 sq. ft.
Recumbents: Effective Drag Area
LoneWheelBase: 4.62 sq. ft.
ShortWheelBase1: 3.57 sq. ft.
ShortWheelBase2: 2.33 sq. ft.
Streamline Lowracer: 0.32 sq. ft. (world record holder) This must be some ride.
I don't get it!
Except for the Uber "Streamline Lowracer" the numbers for 'Bent's aren't really all that great. "Hands on the drops" rate as well as the "ShortWheelBase1"recumbent.
I must be missing something.
The numbers I'm seeing from a MTB with a garbage can lid are in the "superman" range, better than a "ShortWheelBase2" recumbent.
What am I missing?
No Doubt the RRF is definitely dorky
, but cumbersome, not really."for true efficiency using the online calc at kreutzer its plain and simple", Yes, it seems to be simple, there isn't really that much difference and what there is, doesn't favor a 'Bent.(Well, a 'Bent has to be better on the Butt.)
I mean talk about "looking dorky and cumbersome", that really fits a 'Bent to a "T".
You know, what got me going on this is that I want to go 25 miles @ 25 mph, Seems reasonable. I'm sitting at 18 miles @ 18 mph right now. But to go from 20 mph to 25 mph means you basically have to double the battery pack, and more miles, more batteries yet.
Well, instead of just buying more batteries, I'm looking for efficiencies that I have overlooked or don't understand.
And there is a lot I don't understand about both the components and the entire system. For example, the 4011 of my 408/4011 is a bit slower, but quite a bit more efficient. For example, putting a garbage can lid in front of you makes you 10%-30% more efficient.
A dime here, a dime there....
My point is to look at the variety of things that can be easily improved, not perfected with Lycra, for the most gain to the whole. Great efficient in one area means nothing unless the other 6 or 8 areas are also at some degree of efficiency too.
It's the whole that we ride.
"what ever you want what ever you like ", that's exactly why there are so many different tasting beers, so many different tastes.
Personally, I favor a strong IPA, but after mowing the lawn, a Bud is just fine.
Later
Kyle
Hi
Yes but your bike isnt a drop bar racing bike, I was making the comparison between an MTB and the lowracer, I made the TDF cyclist as an example of how you could get near to it which is what the calculator also proves.
I dont think Bents look dorky at all, the KMX certainly doesnt however a bin lid stuck to the front of your bike really does look odd, if you want to go efficient then you need to think about taller wheels slimmer bike etc etc this is if you dont want to go to a bent, re do the calcs on the sim for a mtb with nobbly tyres and a low racer or bent with a tailbox and you will see.
Lowell
As for breaking the KMX stops quicker than anything I have and I dont use the rear brake, the KMX has 3 x disc brakes, so it actually has more stopping power than a normal bike, also it has 3 x wheels in order to apply the friction in order to stop the bike, I just dont know where this idea that a 2 wheel bike stops quicker than a bent comes from? it goes against all known laws of physics, please explain? sitting up in the saddle in order to help brake the bike makes little difference on a pushbike, also the KMX can corner faster than any MTB and can change direction very quickly.
I have many many bikes and if you are happy riding around with a bin lid stuck to your bike thinking its helping you then fair play to you, I still think there are better ways to go further faster that actually work, I get the feeling from the response on here that I am somehow mocking you, I am not I am just adding my 2 cents worth.
Knoxie
Yes but your bike isnt a drop bar racing bike, I was making the comparison between an MTB and the lowracer, I made the TDF cyclist as an example of how you could get near to it which is what the calculator also proves.
I dont think Bents look dorky at all, the KMX certainly doesnt however a bin lid stuck to the front of your bike really does look odd, if you want to go efficient then you need to think about taller wheels slimmer bike etc etc this is if you dont want to go to a bent, re do the calcs on the sim for a mtb with nobbly tyres and a low racer or bent with a tailbox and you will see.
Lowell
As for breaking the KMX stops quicker than anything I have and I dont use the rear brake, the KMX has 3 x disc brakes, so it actually has more stopping power than a normal bike, also it has 3 x wheels in order to apply the friction in order to stop the bike, I just dont know where this idea that a 2 wheel bike stops quicker than a bent comes from? it goes against all known laws of physics, please explain? sitting up in the saddle in order to help brake the bike makes little difference on a pushbike, also the KMX can corner faster than any MTB and can change direction very quickly.
I have many many bikes and if you are happy riding around with a bin lid stuck to your bike thinking its helping you then fair play to you, I still think there are better ways to go further faster that actually work, I get the feeling from the response on here that I am somehow mocking you, I am not I am just adding my 2 cents worth.
Knoxie
At 57mph (my top speed) a Roadster type bike would need 7000W, but a lowracer bent needs just 2000W. 5000W at that speed is around 50lbs force, which is the braking advantage an upright like mine would have without taking other factor into account. Sit more upright and put your knee out and the air brake effect is much more pronounced. The extra contact patch of a tadpole should be worth a little, but each tire carries only half the weight. Much like putting tires twice as wide on your car can only increases grip slightly, but can actually decrease grip if the vehicle is too light due to low tire temperature.
Braking from top speed, does the KMX lock up the tires or lift the rear wheel?
As for corner speed, I'm not really sure which is faster. It would probably depend more on tires, setup and rider but it would be interesting to do skid pad tests on both types. I have a 100ft tape measure and plenty of parking lots available. Why don't we have a 200ft skid pad challenge, video taped of course? I have lap timing equipment available, and the test would be a 200ft diameter circle of cones with an optical timer to record intervals. Fastest two laps in each direction.
http://www.smithees-racetech.com.au/development/skidpad.html
http://www.sportcompactcarweb.com/features/0403scc_skidpad/
Braking from top speed, does the KMX lock up the tires or lift the rear wheel?
As for corner speed, I'm not really sure which is faster. It would probably depend more on tires, setup and rider but it would be interesting to do skid pad tests on both types. I have a 100ft tape measure and plenty of parking lots available. Why don't we have a 200ft skid pad challenge, video taped of course? I have lap timing equipment available, and the test would be a 200ft diameter circle of cones with an optical timer to record intervals. Fastest two laps in each direction.
http://www.smithees-racetech.com.au/development/skidpad.html
http://www.sportcompactcarweb.com/features/0403scc_skidpad/
knoxie:
"Yes but your bike isn't a drop bar racing bike"
No, it isn't a drop bar bike, but with the RRF, it has the same drag numbers as the "tri bike".
"re do the calcs on the sim for a mtb with nobbly tyres and a low racer"
Please, Let's compare apples to apples.
"if you are happy riding around with a bin lid stuck to your bike thinking its helping you then fair play to you"
Well, I'm not "thinking" that it helps. It Actually does.
While this isn't "Rocket Science", it is Science, with repeatable results.
You don't believe, by all means, prove it to yourself. Go find a hill on a calm day and take a couple runs and report the results back here, I will be most interested hear other reports.
If you have others ways of increasing efficiencies by 10%-15% for $9.00, I'm all ears. Just trying to learn.
Lowell:
You've been 57 mph on a upright bike, Holy Cow!
I bet you know something about Braking.
Later
Kyle
"Yes but your bike isn't a drop bar racing bike"
No, it isn't a drop bar bike, but with the RRF, it has the same drag numbers as the "tri bike".
"re do the calcs on the sim for a mtb with nobbly tyres and a low racer"
Please, Let's compare apples to apples."if you are happy riding around with a bin lid stuck to your bike thinking its helping you then fair play to you"
Well, I'm not "thinking" that it helps. It Actually does.
While this isn't "Rocket Science", it is Science, with repeatable results.
You don't believe, by all means, prove it to yourself. Go find a hill on a calm day and take a couple runs and report the results back here, I will be most interested hear other reports.
If you have others ways of increasing efficiencies by 10%-15% for $9.00, I'm all ears. Just trying to learn.
Lowell:
You've been 57 mph on a upright bike, Holy Cow!
I bet you know something about Braking.
Later
Kyle
TylerDurden
100 GW
Lowell said:
We shall integrate a lever, which spreads the fairing out flat.
Or... the lever will open a duct to the regen-turbine. :wink:
Lowell, go any faster and you will need a 'chute.
TylerDurden said:Lowell said:
We shall integrate a lever, which spreads the fairing out flat.
Or... the lever will open a duct to the regen-turbine. :wink:
Lowell, go any faster and you will need a 'chute.
Air brake flap like the McLaren F1 :lol:
Probably won't be needing a chute on anything 2 wheeled, but I hope one day I can get kicked out of the local NHRA dragstrip for no parachute with a 4 wheeler. (150+mph in the 1/4 mile requires one)
Kyle said:knoxie:
"Yes but your bike isn't a drop bar racing bike"
No, it isn't a drop bar bike, but with the RRF, it has the same drag numbers as the "tri bike".
"re do the calcs on the sim for a mtb with nobbly tyres and a low racer"
"if you are happy riding around with a bin lid stuck to your bike thinking its helping you then fair play to you"
Well, I'm not "thinking" that it helps. It Actually does. I believe that have I proved that it does:
4th Street Hill: A no power roll down a 8.3% hill for 1200 feet (100' vert.).
Without "Rubbermaid Roughneck Fairing" ~21.5-mph @~800' 24.6-mph @~1100' 24.6 mph Terminal Velocity
With "Rubbermaid Roughneck Fairing" ~23.5-mph @~800' 30.3-mph @~1200' Terminal Velocity not reached, still accelerating at bottom of hill!
While this isn't "Rocket Science", it is Science, with repeatable results.
You don't believe, by all means, prove it to yourself. Go find a hill on a calm day and take a couple runs and report the results back here, I will be most interested hear other reports.
If you have others ways of increasing efficiencies by 10%-30% for $9.00, I'm all ears. Just trying to learn.
Lowell:
You've been 57 mph on a upright bike, Holy Cow!
I bet you know something about Braking.
Later
Kyle
You yourself said it was high on the dork meter not me initially ! so why did you get upset about that? looking back at the bin lid picture I can only see its presenting more drag? its not high enough to deflect the wind over your head? you would be a lot better off just wearing Lycra and getting some drop bars and tucking in, also if efficiency is your main concern why fit your motor to a full suspension bike? peddling against bobbling rear suspension is hardly efficient, a rigid bike is much better, more power down on the road.
Its a nice looking machine I just think the bin lid spoils it also 26-30 mph isnt 30%? you can get proper clear cycle fairings for upright bikes, Chas on here used one on his USPD, mainly to keep the rain off.
Its hard to attach any fairing to a bike without it compromising the looks of the machine, I have a friend who works as an aerodynamics engineer for Renault F1, I will send him the pictures of your bike to see if he can help.
You can increase your range by peddling more and using less throttle, you will go further get fitter and live longer hopefully, I can do 50 miles on 7.5AH, you just have to train a little.
Cheers
Knoxie
Geebee
1 kW
We have actually had serious discussions on the velomobile mailing regarding braking chutes for downhills as the drag is so low that brake fade/failure is a real issue in hilly environments and even worse some of the riders have actually fitted and use them.
One of the biggest problems with fairing an upright bike is high winds as they tend to prone to being blown of course if the fairing is of significant size, it is even a factor when parked.
One of the biggest problems with fairing an upright bike is high winds as they tend to prone to being blown of course if the fairing is of significant size, it is even a factor when parked.
OK Knoxie, I'll bite.
looking back at the bin lid picture I can only see its presenting more drag?
Are you not sure or do you just not know? :lol: Check the numbers from my test. Still not sure? Do the test yourself! The math on the RRF at 25 mph is a saving of 213 watts. I know the RRF just doesn't look "right" , that it shouldn't help that much. I didn't think that it would help as much as it did. I started this as a joke, but there it is, Drag is always good to lose.
I used to design windsurfing sails, and I learned that aerodynamics are rarely intuitive. What feels like power (lift) in the sail can really be drag. You sheet in hard, and you feel like you've power up the sail, but really all you did was make more drag. Lift and Drag feel pretty much the same. That's where testing comes in, it tells you what is real and what is just a really nice idea.
What feels like power in our Motors, might really be resistance and the making of heat. After making a Power To Wheel/Power Out Of Battery chart, I saw how wasteful using full throtlle at low speeds is.
its not high enough to deflect the wind over your head?
Agreed, it can be made better by going higher, but tucking didn't change the speed, so maybe that isn't a problem. (More Testing)
why fit your motor to a full suspension bike?peddling against bobbling rear suspension is hardly efficient, a rigid bike is much better, more power down on the road.
Smooth ride for a rough world. I live in an old town with some old streets with big pot holes. I think that a suspension is a great thing, especailly at higher ebike speeds. They are just so much more comfortable to spend time on. Hard Frames are, well HARD. There must be some energy lost to the suspension, but the bobbling thing is over played. I rode Hard frames for years and what losses there are to a suspension, I'm more that willing to pay for, for the smooth ride. Did I mention the front disk brake?
Remember, This A Test, This Is Only A Test!
Yeah there are clear ones out there for $200 or so. But, no way was I willing to fork out that much, but with what I learned from the RRF, I might be convinced. I wonder how the RRF compares to "real ones"? They do look nice though.
Later
Kyle
looking back at the bin lid picture I can only see its presenting more drag?
Are you not sure or do you just not know? :lol: Check the numbers from my test. Still not sure? Do the test yourself! The math on the RRF at 25 mph is a saving of 213 watts. I know the RRF just doesn't look "right"
, that it shouldn't help that much. I didn't think that it would help as much as it did. I started this as a joke, but there it is, Drag is always good to lose.I used to design windsurfing sails, and I learned that aerodynamics are rarely intuitive. What feels like power (lift) in the sail can really be drag. You sheet in hard, and you feel like you've power up the sail, but really all you did was make more drag. Lift and Drag feel pretty much the same. That's where testing comes in, it tells you what is real and what is just a really nice idea.
What feels like power in our Motors, might really be resistance and the making of heat. After making a Power To Wheel/Power Out Of Battery chart, I saw how wasteful using full throtlle at low speeds is.
its not high enough to deflect the wind over your head?
Agreed, it can be made better by going higher, but tucking didn't change the speed, so maybe that isn't a problem. (More Testing)
why fit your motor to a full suspension bike?peddling against bobbling rear suspension is hardly efficient, a rigid bike is much better, more power down on the road.
Smooth ride for a rough world. I live in an old town with some old streets with big pot holes. I think that a suspension is a great thing, especailly at higher ebike speeds. They are just so much more comfortable to spend time on. Hard Frames are, well HARD. There must be some energy lost to the suspension, but the bobbling thing is over played. I rode Hard frames for years and what losses there are to a suspension, I'm more that willing to pay for, for the smooth ride. Did I mention the front disk brake?
Remember, This A Test, This Is Only A Test!
Yeah there are clear ones out there for $200 or so. But, no way was I willing to fork out that much, but with what I learned from the RRF, I might be convinced. I wonder how the RRF compares to "real ones"? They do look nice though.
Later
Kyle
Like my dad always said:
One test is worth a thousand opinions...
One test is worth a thousand opinions...
Malcolm
10 kW
I don't like to interrupt an argument, but...
It's really blustery here today and I've just come back from a ride – 14 miles on a roughly circular route. On open sections of road I was being pushed around a lot by the gusts. Wh/mile consumption was almost 88, compared to the usual 75 or so for the same route. Does anyone know of any fairing designs that are intended specifically to reduce lateral wind loads? From what I've heard most of them tend to increase susceptibility to side winds. I guess you would need a fairing that balanced the wind load between front and rear, so you would probably need a tail fairing as well.
It's really blustery here today and I've just come back from a ride – 14 miles on a roughly circular route. On open sections of road I was being pushed around a lot by the gusts. Wh/mile consumption was almost 88, compared to the usual 75 or so for the same route. Does anyone know of any fairing designs that are intended specifically to reduce lateral wind loads? From what I've heard most of them tend to increase susceptibility to side winds. I guess you would need a fairing that balanced the wind load between front and rear, so you would probably need a tail fairing as well.
Kyle said:
Whats here to bite on? We just have differing opinions thats all? I didnt think the thread had got warm in any way? I have just been offering my opinion as that is essentially the basis as to what most forums are about is it not? for me to say that I think the lid looks like it offers more drag is just my opinion, now if your tests prove that is doesnt then thats ok?
I get the feeling that more than 1 or 2 people on this thread and in general like Richard seem to be a little cool with me for some reason or another thats fine I dont mind, I wont join in with any of the discussions or help anyone who has issues or problems I will leave it to folks that know better, I can see where this forum is heading which is a shame.
If I cant have an opinion without people wanting to bite I wont bother posting.
I'm off
Knoxie
d
100 W
knoxie,
you're right to express your opinion.
in my opinion the garbage can lid would probably add a considerable amount of drag unless you have a tailwind in which case it would act like a sail. no offence, and I'm sure you already realize this, but it also looks quite bad... i'd personally rather go a couple MPH slower than have a garbage can lid strapped to the front of my bike.
also, knoxie, don't let people on the forum piss you off, just smile and take it for what it is... if you don't like what they say, just ignore em, but keep on posting, you're a valuable member here, and the reason I joined.
-D
you're right to express your opinion.
in my opinion the garbage can lid would probably add a considerable amount of drag unless you have a tailwind in which case it would act like a sail. no offence, and I'm sure you already realize this, but it also looks quite bad... i'd personally rather go a couple MPH slower than have a garbage can lid strapped to the front of my bike.
also, knoxie, don't let people on the forum piss you off, just smile and take it for what it is... if you don't like what they say, just ignore em, but keep on posting, you're a valuable member here, and the reason I joined.
-D
d
100 W
Kyle said:
sounds like you had a tailwind.
Well I don't think the poster intends to permanently attach a tote lid to his bike (hopefully), but it's more a proof of concept and I have done the same thing with various projects. It's a lot more encouraging to see favorable results on a quick and dirty mockup than invest hours of machining/welding/resin time without knowing if it will give the percentage improvement you're looking for.
I'm not an engineer, but I do have some real world aero experience as well as playing around with different designs in Fluent. http://www.fluent.com/
My opinion is that the tote lid is not that bad of a shape, being slightly convex with folded edges. An exposed rider has an absolutely terrible drag coefficient, as anyone who has ridden a naked motorcycle can attest to. As long as the frontal area of the fairing is not excessive, it will net significant gains over a rider exposed to direct airflow.
I'm not an engineer, but I do have some real world aero experience as well as playing around with different designs in Fluent. http://www.fluent.com/
My opinion is that the tote lid is not that bad of a shape, being slightly convex with folded edges. An exposed rider has an absolutely terrible drag coefficient, as anyone who has ridden a naked motorcycle can attest to. As long as the frontal area of the fairing is not excessive, it will net significant gains over a rider exposed to direct airflow.
So I've went out looking for an aero fairing like thing to add onto my bike. I came up with a saucer, made a few holes and attached it with zip ties on each end of the handlebar, and in the center of the fork bridge. (it was string in the photos). I had to keep the front brake detached and fully open for this. For a measuring device, I grabbed a clock and duct taped it to the stem.
Pics:
I went out of my house and used the street right next to it. It's a steep-ish drop & then it kinda levels out. Dunno the grade, but the steeper part must be around 4-6%. I went down a few times, with and without the fairing.
I found that for one thing the run was too short for the clock's precision. it's graduated to 15 secs and I guesstimated to 5 secs close, all my runs took around 45secs. A longer test hill and more precise clock would help.
Without the fairing I was able to tuck normally, this position was much lower with my back nearly flat, one hand behind my back and jaw real close to the stem. I found the fairing was much too high and too far back. I was not able to tuck normally, instead I had to lean off the back of the bike with my head much higher then normal.
Having to lean off the back of the bike was double plus ungood as my rear tire has been mushy & robbing a noticeable amount of power for the past 2 weeks or so, I think having to put my weight on it had a significant influence on my results. Next time, make sure both my tires are properly inflated, maybe note the pressures along with times and such.
I think a smaller dish would have done better, less high and much less wide.
Pics:
I went out of my house and used the street right next to it. It's a steep-ish drop & then it kinda levels out. Dunno the grade, but the steeper part must be around 4-6%. I went down a few times, with and without the fairing.
I found that for one thing the run was too short for the clock's precision. it's graduated to 15 secs and I guesstimated to 5 secs close, all my runs took around 45secs. A longer test hill and more precise clock would help.
Without the fairing I was able to tuck normally, this position was much lower with my back nearly flat, one hand behind my back and jaw real close to the stem. I found the fairing was much too high and too far back. I was not able to tuck normally, instead I had to lean off the back of the bike with my head much higher then normal.
Having to lean off the back of the bike was double plus ungood as my rear tire has been mushy & robbing a noticeable amount of power for the past 2 weeks or so, I think having to put my weight on it had a significant influence on my results. Next time, make sure both my tires are properly inflated, maybe note the pressures along with times and such.
I think a smaller dish would have done better, less high and much less wide.