Mythbusters aero cycle tests

[PeterS]

http://www.youtube.com/watch?v=krCHwg3IeDo

[dcb]

looks like they added a lot of extra frontal area vaguely resembles an airfoil.

[darcane]

Originally Posted by PaleMelanesian

It was a new episode last night, so likely not available elsewhere, yet.

The bikes were progressively cleaner by date - the 80's bike was the worst. The new 2010 Yamaha 250 was the cleanest bike, and proportionally cleaner with the aero fairing. That's good news. I believe it is fuel injected. Still no catalytic converter I believe, so that's where the emissions came from.

Not sure if it was by total emissions or by percent. Still, even if it was by percent it comes out as worse. At maybe 1/2 the car's fuel consumption but 5x (by percent) the emissions, that's still 2.5x total output. If it was total, that's WAY worse.

They specifically mentioned that they chose the bike because it was small displacement, fuel injected, and had a catalytic converter.

Cats started showing up on bikes shortly after EFI. My '06 Ninja 650R has EFI and a cat. Although, I don't think the regulations are as strict for bikes and cats though. There is no testing that I am aware of and all the exhaust systems I've seen don't have cats, so I have to assume that it's not illegal to remove them like it is with a car.

Their measurements were in absolute numbers, not percentages. They did compare these numbers later as a percentage of the cars emissions though. The '00s bike's CO and NOx emissions were like 3000% and 8000% of the '00s car's but not because the bike was high, only because the car was essentially 0.

[darcane]

Oh, and since it will probably come up. In the show, they don't address emissions created during the manufacturing process... but they do in the online aftershow. Even though there are a lot less materials in a bike, their research indicates that the economies of scale allowed the cars to have equivalent, if not lower, emissions than the bikes since bikes have much lower production numbers.

MythBusters: Bikes and Bazookas : Videos : Discovery Channel

[euromodder]

Originally Posted by BHarvey

A well tuned bike will output the same ppm as a car but will do it without all the emissions equipment, but this will require some dyno time to get it right.

That's the problem, bikes aren't required to pass the same emissions tests as cars.
While bikes obviously comply to the emissions standards set out for them, the standards themselves are a lot less stringent.

[alvaro84]

Heck, even smelly 2-stroke scooters are popular here, mostly because they're cheap. Larger bikes have emission norms, but I don't know how stringent they are. My Teresa, for example, complies euro2, and is equipped with EFI (AFAIK it has a narrow band O2 sensor, it's closed loop at lower revs/load, and it becomes open loop at a point) and a cat. For euro3 f650s needed a 2nd spark plug (until 2004 they had only one spark plug, which is interesting because the former, carbureted models had 2).

And I don't know how these norms compare to car norms...

[TFS]

I saw the show last night and did a google for a place to sound off, and found this one!

I thought it was pretty bad. I hope they don't think full streamlining or using heat shrink Mylar is a new idea!

[Frank Lee]

Here is the test of motorcycles' effect on traffic and emissions that we wanted:

New research indicates motorcycle commuting reduces traffic congestion and emissions

[euromodder]

Originally Posted by Frank Lee

Here is the test of motorcycles' effect on traffic and emissions that we wanted:

New research indicates motorcycle commuting reduces traffic congestion and emissions

As PDF :
http://www.tmleuven.be/project/motor...apport_Eng.pdf

It's a computer simulation, applied to a particularly congested stretch of highway, so some reservations apply.

The stretch of highway actually contains a merger of 2 very busy highways - one 2 lane, the other 3 lane, merging onto only 4 lanes.
Then it crosses the equally bussy Brussels' outer ringroad.
Google's Streetview car was caught in traffic as well ..

There are some other effects as well :

Excluding foreign traffic, there are about 25 times fewer motorcycles than cars and trucks on our roads, with the annual mileage being a fraction of that - only 1/3 rd the car average.

Despite that, a staggering 15% of our road casualties are motorcyclists !

At 4% of vehicles, and less than 1.5 % of vehicle-kilometers, they represent 4 times the death toll if we look at the number of vehicles, and a whopping 10+ times the death toll when viewed by vehicle-kilometers.


Introducing more motorcycles in traffic while at the same time making them do many more kilometers, simply doesn't look like a brilliant idea to me.
It'd be a massacre.

[Frank Lee]

Don't worry; they'll make more.