Value of 180 degree front fender coverage

[zrxdean]

I've seen a lot of pics of LSR bikes with fabricated or Buell front fenders,  with 180 degree coverage.  I remember that the 2000-01 ZX12r had a pretty full front fender also.

Any of you top speed demons play with your front fenders? Are there aftermarket 'aero' fenders available?

[narider]

Any of you top speed demons play with your front fenders? Are there aftermarket 'aero' fenders available?

Not sure what you're wanting, but this is one I wanted as you see it... and when time got short for me these guys came thru so I didn't have to make it myself. It's not Busa, and it's not full 180* coverage(both for my own reasons), but if you know what you want these guys will do it less expensive then anyone else in the industry.
Todd
http://undergroundchopper.com/IronheadRacer.htm

[zrxdean]

That's just what I mean, thanks. I imagine that this kind of thing is just icing on the cake, but I wonder what this sort of attention to detail is worth. If Suzuki and Kawasaki went to the trouble of designing extended coverage fenders, depite what some consider unattractive styling, it must offer more than a little advantage.

Dean

[donpearsall]

I wonder about the value of streamlining the front wheel too. Intuitively, it seems like a good idea to make everything as streamlined as possible. However, remember that the front wheel is just ahead of the big draggy radiator and engine. Those things must displace their surface area anyway (which also includes the surface area of the front wheel). So does it make any difference to streamline the front wheel, when there is far more drag behind it?

I really don't know. Anybody have any empirical evidence that it helps or not?

Don

[Pete]

Just make sure whatever you create isn't a lift-producing shape, you don't want the front wheel getting airborne at 220mph due to aerodynamic lift. If Mercedes can get it wrong with their LeMans racers anyone can.

[gazza414]

I wonder about the value of streamlining the front wheel too. Intuitively, it seems like a good idea to make everything as streamlined as possible. However, remember that the front wheel is just ahead of the big draggy radiator and engine. Those things must displace their surface area anyway (which also includes the surface area of the front wheel). So does it make any difference to streamline the front wheel, when there is far more drag behind it?

I really don't know. Anybody have any empirical evidence that it helps or not?

Don,
 it may well reduce the drag by cleaning up the airflow around the bike??? dunno

As you are no doubt aware its the hole that we leave behind is our enemy.

Geri ( Pete ) that was an Ozzie in that car if I'm not mistaken...he lived to see another day on went onto F1

ps Pete..ashes are on there way home mate

[hawkwind]

Geri ,that is the result when ground effect downforce is removed suddenly
Don the front wheel 'tyre assembly is subject to 3 forms of drag
1. form drag ,basically its  shape ,push a wheel at speed through the air and it creates drag ( look at it as NOT rotating ) the fairing (fender ) decreases this drag   
2. rotate the wheel at any velocity and it creates drag ( even when stationary and rotating) placing a fender around the wheel with with a pumper stoper ( a means of limiting the pumping drag / losses ) will reap gains in mph
3. form drag from side winds ,unfortunatly the better the aerodynamics for forward motion the worse the effects of side winds
 it will also experence lift or downforce depending on the fenders construction
aerodynamics is a bloody complex subject 

in this pic you can see the fender I made for my landspeed bike ,as well as all the aero bodywork ,only problem is none has beeen wind tunnel tested

gary

[donpearsall]

That is a very complex fairing. Congratulations for doing all that work. I see you made a rear fairing to enclose the rear wheel and streamline the waste air. What did you do to stop the wheel from pumping air (your pumper stopper)?

Don

[Pete]

ps Pete..ashes are on there way home mate

Your boys deserved them, our lot just sat around for a year congratulating themselves, whereas yours formulated a battle-plan. and carried it out ruthlessly



Back on topic - Lorcan Parnall's bike actually picked-up speed after he removed the front fender completely (GPz650turbo). His theory was that down-force created by the shape was reducing load on the rear tyre and reducing traction.

[hawkwind]

That is a very complex fairing. Congratulations for doing all that work. I see you made a rear fairing to enclose the rear wheel and streamline the waste air. What did you do to stop the wheel from pumping air (your pumper stopper)?

Don

Thanks for the comments  Don its not my idea( pumper stopper) check out  http://www.landracing.com/forum/index.php/topic,1681.0.html

   L orcan Parnall's bike actually picked-up speed after he removed the front fender completely (GPz650turbo). His theory was that down-force created by the shape was reducing load on the rear tyre and reducing traction.

Geri ,doubt it ,it would only increase the unsprung weight on the front wheel/tyre  more likely changed the Cd / A equation  ie made SFA change to the Cd but lowered the frontal area somehow, Matt Capri increased his landspeed record on a modified BMW by removing his lower fairing and fender ,it made not much difference to the Cd ( bikes are basically bricks , but improved the frontal area enough to actually go faster thats another possible reason
Gary

[2fast4u2c]

Hawk, quite the fairing.  Go fast this year my friend.

Guy

[hawkwind]

Hawk, quite the fairing.  Go fast this year my friend.

Guy

G'day Guy  thanks mate  by the way what are you up to there days ?
Gary

[deezuhl]

Geri ,that is the result when ground effect downforce is removed suddenly
Don the front wheel 'tyre assembly is subject to 3 forms of drag
1. form drag ,basically its  shape ,push a wheel at speed through the air and it creates drag ( look at it as NOT rotating ) the fairing (fender ) decreases this drag   
2. rotate the wheel at any velocity and it creates drag ( even when stationary and rotating) placing a fender around the wheel with with a pumper stoper ( a means of limiting the pumping drag / losses ) will reap gains in mph
3. form drag from side winds ,unfortunatly the better the aerodynamics for forward motion the worse the effects of side winds
 it will also experence lift or downforce depending on the fenders construction
aerodynamics is a bloody complex subject 

in this pic you can see the fender I made for my landspeed bike ,as well as all the aero bodywork ,only problem is none has beeen wind tunnel tested

gary

I looked at the LSR bodywork and its similar to yours no side holes in the fairings etc.. im just taking a guess here but isnt it possible w/o the holes in the side fairings all the air that makes way thru the front creates a parachute type effect cause it has nowhere to pass thru?? im thinking unless you go to a different radiator setup where you dont need that huge gap in the front of the bike itll create drag.. what do you guys think??

[SPARKY1397R]

that would make sense. 

[JACKD]

At the power levels and distances required for LSR, cooling becomes a really important part of the tuneup to maintain those levels.
Some of it might be done with excess fuel to help carry away the heat but that is not enough.
Flash HP on the Dyno is only a start and the loads seen by an LSR application are something else all together.

[hawkwind]

[/quote]

I looked at the LSR bodywork and its similar to yours no side holes in the fairings etc.. im just taking a guess here but isnt it possible w/o the holes in the side fairings all the air that makes way thru the front creates a parachute type effect cause it has nowhere to pass thru?? im thinking unless you go to a different radiator setup where you dont need that huge gap in the front of the bike itll create drag.. what do you guys think??
[/quote]

Deezuhl there are openings in my fairing but reduced as much as possible , my aim is to use the pressurised air comming in through the front openings to perform 2 tasks ,1. for engine cooling,as you can see  , 2. to direct that air up through the inside of the fairing/screen and the area around the handle bars , this area is subject to a partial vacuum and any improvements will be a gain ,as already stated ,without an aerodynamist ,wind tunnel and cfd programmes ,my guesses are as good as anyones 
Gary

[donpearsall]

Hawkwind,
What  you say about directing the cooling air up through the handlebars is a good idea, but with one drawback. When I did that, the air coming up at my face and chest at 200mph was so much that I had a hard time keeping my head down. It kept blowing me back up and then my helmet would hit the stream coming off the windshield and slow me down.

When I installed the inner fairing panels it helped a lot and I was able to keep down a lot better.

Don

[JACKD]

The air was proably a little hot also.

[2fast4u2c]

Hawk, quite the fairing.  Go fast this year my friend.

Guy

G'day Guy  thanks mate  by the way what are you up to there days ?
Gary

Building a new Nitrous motor as we speak.  I just can't seem to find all the spare money needed to build a turbo.