Downforce on bikes

[< I Fly >]

I notice that bike manufacturers don't seem to make an issue out of downforce at all, especially in comparison with race cars, which throw so much wind upward that they can ride on a level, upside-down track and not fall off.

Why is there this discrepancy?

[jmillheiser]

downforce would likely be detrimental to the handling of a bike. Downforce pushes down on the vehicle at speed, on a bike this would likely cause it to lowside in a high speed turn from the downforce pushing the bike down.

the gyroscopic force of the bikes wheels is what keeps it from falling over in a lean, you dont want to have anything counteracting this force or the bike will fall over.

its just an accepted fact that a race bike wont handle high speed turns as well as a race car

[camthepyro]

The downforce that indy cars (the kind of cars the can drive upside down) make is mostly for traction in the turns, and in those turns they're going 100+, but bikes aren't going nearly as fast in corners, and the method of turning (leaning) is unique to motorcycles. Basically, I don't think it's neccessary.

[BigChickenStrips]

the method of turning (leaning) is unique to motorcycles.

i beg to differ:


mercedes f400 carver leans into turns.

lol, just messin' with you.

[camthepyro]

Lol, I knew someone would go and through something like that in my face. I meant for the most part, it's unique to motorcycles.

[Sev]

Those indy cars generate so much HP that if they didn't have those aerodynamics the cars would be impossible to drive forwards, you'd just spin the tires until they exploded. With the design that they do have the cars just literally suck themselves into the ground and away they go.

*edit* what we do need is for someone to improve the aerodynamics of bikes. As it stands between the bikes designs, and their air intakes/routing you might as well be pushing a sheet of plywood down the highway.

This is one of my favorite quotes of all time on the subject:

Compare this [motorcycle] with natures best streamlining - a trout or salmon. A fish's largest cross section is up near the front, saving the rest of the length for a slow taper to the tail, recovering the energy given to the water that the foreparts have accelerated aside. The result is very little wake and little loss to turbulence. Tesult: high speed, low power.
What psses for a modern motorcycle design is as though we chopped off everything to the rear of the gills, propped the fishes mouth open, and stuck a telescopic fork and wheel in it. Somewhere behind this remnant crouches therider. As aerodynamics go, this is a nasty piece of work, for the lumpy presence of the front wheel disturbs airflow to the fairing, after which nothing is done to recover the energy consumedin pushing this collision of objects through the air. This generates a large energy-rich turbulent wake and a drag co-efficient perhaps as good as a bread truck. Because so little can be done to imrpve this 48-year-old creation, stlists enjoy the private joke of tacking on irrelevant supersonic scoops and flat planes of early. Result: fuel consumption comparable to that of automobiles.

This is just a small excerpt from the April 2006 Issue of Cycle World, page 22.

But I think it sums up the biggest problem with bikes now a days.

[TechTMW]

But I think it sums up the biggest problem with bikes now a days.

The biggest problem with bikes nowadays is that they have to sell. You could create an aerodynamically 'better' bike, but no one would buy it. (that was a good article btw!)

[< I Fly >]

But I think it sums up the biggest problem with bikes now a days.

The biggest problem with bikes nowadays is that they have to sell. You could create an aerodynamically 'better' bike, but no one would buy it. (that was a good article btw!)

Because it would look so weird?

[Sev]

Yeah pretty much, but there must be some things that can be done.

[TechTMW]

Because it would look so weird?

http://www.tonyfoale.com/Articles/Aerod ... roOpen.jpg

You tell me ...