Ducati Monster Forum

Will someone explain this to me?  It can't be weight savings.  Aerodynamics?  I've seen it on older race bikes as well as the 250's/125's, but I can't figure out the advantage.

http://www.superbikeplanet.com/image/2009/motogp/assen/hugo/5.htm (http://www.superbikeplanet.com/image/2009/motogp/assen/hugo/5.htm)

I think it's to improve stability when there are bad cross-winds, E.

like dimples on a golfball.

Not only is he good looking but he is brlliant as well!  [cheeky]

Not the same as dimples in a golf ball. Golf ball dimples create a turbulent boundary layer that keeps the flow around the golf ball from separating prematurely. The effect is the reduction of form drag. the holes in the upper fairing help reduce the effects of cross wind and some drag but in a completely different way.

okay, thanks! [thumbsup]

IMO, it's mostly for when they're laid over like this:

(http://www.superbikeplanet.com/image/2009/motogp/assen/1/1.jpg)

Leaned over like that, a gusty side wind is going to load up the front tire.
May not be too fun at ~300 kph when you're sliding both tires.
When it was windy at El Mirage or Bonneville, it always got my attention.  :P

The DMF:  Home of the most brilliant, twisted minds since 2007.

I love this place.

i kinda disagree. i think it smooths out the airflow in high speed straights. the low speed turbulence behind the fairing would tend to build up the faster you go, the airholes allows the highspeed flow to break up that lowspeed area and flow it smoother past the rider.
will be interesting to see if they reduce the height of the fairing in the future to do the same thing.

so why do you think we don't always see them in that case?

It seems like only on certain tracks they show up.  Or could it be certain forecast? 

The might be be placebo's too like matched tires?

mitt

I think one of the mechanics got drunk on Dutch beer and went ape shit with the drill and due to new Dorna cost cutting rules they only had the one upper fairing. [laugh]

i was suggesting that it's not to simply 'smooth out the airflow in high speed straights' -- or else we'd see it all the time, on all the bikes.  and cars.

Guess it is for cutting down the affect of the wind issues they were having in Spain
http://www.motogpblog.com/archives/916 (http://www.motogpblog.com/archives/916)

pg 11 Stoner suffers bad wind
http://issuu.com/motorcyclenews/docs/mcn060509?mode=embed&layout=grey (http://issuu.com/motorcyclenews/docs/mcn060509?mode=embed&layout=grey)

actually you might have seen it and not known it. Jim Hall used it on one of his CanAm cars. well canam was right. and jim hall did some great designs... but i miffed the make of the car wiith the holes. it was a Lola

(http://www.ultimatecarpage.com/images/large/262/Lola-T260-Chevrolet_1.jpg)

Hall's neatest car was the 1970 2J Chaparral that had two engine driven fans that created downforce sucking the car to the track. It was quickly banned bcause it worked so well. Neat stuff. Don't know if that one had any holes in it.

anyway: they say it helps tip the bike into corners when there's a strong cross-wind.  doesn't pertain to the straights.

i didnt' read where it says it helps with the corners. what i read is they were getting a lot of cross winds. allowing the air to flow across the bike and through the fairing either in a straightaway or corner would be a huge benefit.

no doubt.. i'm just sayin' that ducati says it's for the tip-in.

now that people mention about the tip in issue, the holes in the fariing at that area would sorta make a lot more sense now, afterall the holes are at the fartheset point of the moment arem from the contact patche of the wheel so crosswind reduction at the point would probably help tip in a little without affecting the aerodynamics that badly for the straights... hmmm... interesteing what those guys will come up with.