Ok, as a mechanical engineer BS/MS, I'm having trouble following the rather complex FBD. However, to give you (Paul) credit, there are a lot of forces going on in this case, and it is no easy task to explain in simple terms.
I would like to provide some personal experience as evidence to support your point. Back in early 1990's I was fortunate to have owned a Trimble Aero TT. We purchased it from James Trimble himself in his little shop in MA.
I've raced and trained on this bike for years and still have had my fastest TT's times on it (may have to do with being 25 yrs younger). In riding it with a disc in gusty wind conditions, it did not blow me around noticeably (I was 145-150 lbs then).
I now ride a Look 596, typical tri bike design with a 90 mm front wheel. Riding in wind or passed trucks, this 90 mm front wheel wants to through me off the bike and into the ditch if I'm not ready.
All of my experience will tell me that the Andean will handle and climb like a traditional bike. The biggest factor in wind will be your selection of what rim depth to ride in the front.
Below is the actual bike I am talking about: That rig had crazy cross sectional area and handled similar to a traditional bike. Not nearly as extreme as your 'eye' would suggest. And that is my point. People can't just 'look' at a bicycle design and draw conclusions on handling.
devashish_paul wrote:
Tom A. wrote:
devashish_paul wrote:
BBLOEHR wrote:
Bryancd wrote:
This thing might be a handful coming down from Hawi.
could be one downfall, would have to ride it to know.
I would assume this bike is actually MORE STABLE coming down from Hawi in crosswinds. The problem in crosswinds is when your front end with not much weight gets blow away from you with not much weight under your hands, and with the massive fairing you would actually have a "counterbalance" surface for your entire bike to stay on course. It's why a disk in the rear is more stable with deep dish in the front than with only an 808 or equivalent.
There are very few winds that will take a riders rear end and lift the bike and rear end of the rider up off the pavement, so the rear is actually a massive sail to keep you on track (perhaps Rapp can explain this better)
OK OK OK....this entire topic ended up bugging me over the day tomorrow. I always feel that engineers do themselves the biggest disservice by trying to explain things with technical terms and equations and greek alphabets. I like how the economist magazine explains science and engineering problems. No numbers, no technical words, so while I MAY be wrong below I don't think I am.
Engineers use this thing call "free body diagrams" to show how an object reacts to forces. Basically they draw a dot or line and then the draw all these imaginary arrows all over the object with some numbers to denote the scale of those forces to try to figure out how the body moves. So let's try this. Imagine a bike rolling along with the rider on top and suddenly a big gust of wind comes from the right. The front wheel would "turn left" since there is little weight on top of the leading edge of the wheel to hold it on track. This would make the rider on top want to "fall right". But at the same point imagine his entire body and rear wheel and frame also being pushed by another arrow while he is "wanting to fall right". Since the rear wheel is stick to the ground and won't easily change direction as he's feeling like "falling right" that imaginary arrow is pushing the rear wheel, frame and body to "fall left". If you just placed a sale upright in that same wind, it would fall over to the left. If you placed a bike frame on a stand with no front wheel without motion it would want to "fall left". So now you have one small force on the front wheel wanting to make you "fall right" but a much more massive force on the rear wheel wanting to make you "fall left". On top of this is your semi rigid body connecting the two sets of counter acting forces. On top of this the gyroscopic effect of both wheel is wanting to keep you "going straight". Your straight line momentum of your body + bike is always wanting to keep you going straight.
This is why when you are in Kona you look up the road for the dip in the terrain beside the road and you know that the wind there will suddenly be higher and will "hit you". You can see where it will be and just before you go into it, you "lean into it" to use a subset of the gravitational force (an imagary arrow pointing into the direction of the wind) counter act the wind force (those 2 arrows hitting the front and rear wheels).
Tom A and others did I get this all correct? It's been 32 years since I was in 2nd year mechanics and 31 years since 3rd year fluids....since then I have been dealing with electrons or dealing with the psychology of how to make people part with their money and sign for $$$ for products transmitting said electrons.
