Bikes 'dirtier' than cars.

**Mental Trousers** · 31st December 2005, 19:29

Originally Posted by R1madness

Either that or someone new enters the market and sells a hydrogen powered bike capible of 300mph. Now i would buy that yahoo.

Doesn't have to be hydrogen powered (if you mean combustion efficiency). Just injecting a little bit of hydrogen into a hydrocarbon internal combustion engine magically raises efficiency to 100% (that's fuel burnt).

It does that because the usual petrol combustion raises the heat and pressure enough for the hydrogen to ignite, which then raises the temperature and pressure somemore and burns off anything that's left over to burn (remember a bike engine will still be spewing unburnt hydrocarbons out the back end no matter how its tuned).

**jahrasti** · 1st January 2006, 08:49

When i go for a ride today, I will be so worried about the emissions report that I wont be able to concentrate and will have to pull over and then to save the world i will just push my bike home.

**inlinefour** · 1st January 2006, 08:57

I need to get another high preformance 2-stroke in my shed before Uncle Helen bans them completely. Pretty pointless carrying on about the pollution levels. There are so many major companies making industrial pollution that make motorcycle pollution look irrelevant.

**The Stranger:Me** · 1st January 2006, 09:49

Question for you Motu.
Does the analyser test under an accurately simulated load for a bike?

One of the reasons trains are so fuel ineficient is their massive weight per passenger cars are better in this respect. Bikes are carrying less weight per passenger again. I would have thought this even if the bike motor is real bad it would have a big advantage in this respect.

**SARGE** · 1st January 2006, 11:54

Originally Posted by Ixion

Surely everyone knows that bikes are horrible emission-wise ? I thought that was universally accepted. And we care because ? Get them to hook Petal up to their analysers , and watch them all have heart attacks on the spot !.

me too... the leaded race fuel i run would fry the machines ... hehehehe

im such a dirty bastard.,..

**Motu** · 1st January 2006, 12:42

Originally Posted by CaN

Question for you Motu.
Does the analyser test under an accurately simulated load for a bike?
.

No,most tests are done at idle - this is the main reason the proposed emission testing was dropped.Any engine is running at it's most inefficient at idle,and an engine spends more time idling than any other mode,except diesels of course.More time is spent tuning an engine for idle,because that's the most common complaint....drivers and riders are very fussy about their idle.As the motor speeds up then you will see all the monitord levels drop radicaly.But full analisis can only be done using a brake dyno where a reading can be taken every 500rpm of the rev scale - brake dynos are very expensive and not common,you won't find a bike shop with one that's for sure.They do exist - I was at a demo evening at Possum's when he was still alive and they were running a dyno for bikes that could be used as a brake dyno or an inertia dyno,pretty impressive....then Possum showed us his 4x4 dyno,that's how he developed the Possum Link.

**parsley** · 1st January 2006, 13:26

Originally Posted by onearmedbandit

...with hydrocarbon emissions 16 times greater, carbon monoxide emissions 3 times higher disproportionately high emissions of other pollutants.

Does the report say this is by the hour, by distance or by amount of fuel? I would have thought bikes would come out better purely because of the amount of fuel they use as compared to the average car.

You have to look at the bigger picture. Bikes cause far less damage to roads than cars (and a hell of a lot less than trucks), require less space for parking and storage and alleviate traffic problems by being more manouverable and taking up less space on the road than cars.

I reckon if the proportion of cars to bikes on the roads were reversed there would be less pollution and traffic.

**Motu** · 1st January 2006, 13:45

Originally Posted by parsley

Does the report say this is by the hour, by distance or by amount of fuel? .

Disproportionatly is your clue....you can't compare a 125cc bike against an 8,000cc car,the exhaust gas analyser doesn't care what size the motor is,it just reads what comes out the exhaust pipe.

**thehollowmen** · 1st January 2006, 18:58

but on top gear.. didn't they work out the total emissions of the electric trains in london and find out they were worse carbon-wise than cars per head traveling on them?

**oldrider** · 1st January 2006, 21:41

Originally Posted by thehollowmen

but on top gear.. didn't they work out the total emissions of the electric trains in london and find out they were worse carbon-wise than cars per head traveling on them?

That would be with reference to the coal/gas fired power station emissions not the electric trains themselves! They would only have carbon brushes or brake pad emissions to worry about. Or am I just stating the obvious. Cheers John.

**erik** · 2nd January 2006, 00:02

Originally Posted by oldrider

That would be with reference to the coal/gas fired power station emissions not the electric trains themselves! They would only have carbon brushes or brake pad emissions to worry about. Or am I just stating the obvious. Cheers John.

Don't they have diesel generators to drive the electric motors?

**parsley** · 2nd January 2006, 09:58

Originally Posted by erik

Don't they have diesel generators to drive the electric motors?

No, those are diesel trains. Electric trains get their power from the third rail or overhead lines.

**oldrider** · 2nd January 2006, 10:31

You are both right, the official classification for those type are "Diesel Electric" and are independent of the national grid.
The diesel engine drives a generator to power the electric motors that power the driving wheels.
The setup is almost identical to generator sets on board ships providing their internal grid with power.
"Electric" train engines draw their power from the national power grid via an overhead line or an electrified third line. Cheers John.

**crash harry** · 2nd January 2006, 20:40

There's something missing from these measurements though.

An exhaust gas analyser measures percentages of HCs, CO, and lord knows what else on the fancier ones than our one... but that's the key - percentages.

An 1800cc engine idling at about 3.5% CO is pumping out about 3x the amount of impurities that a 600cc engine running at the same percentage is (actually probably not quite 3x, cos the larger engine will not require the same cylinder fill to achieve idle RPM). More if it's an auto cos the engine is doing more work at idle.

However, as Motu points out, our bike engines have more in common with race engines than street engines in the automotive world - even cruisers. No heated manifolds, no vacuum advance, no exhaust gas recirculation, individual carbs, headers, etc. None of the standard automotive economy devices. Bikes have not been subject to the emission control standards that cars have for a number of years in many countries. I believe that is changing now.

However, with the advent of fuel injection this is changing. Cats are becoming more common, and lean-burn injected engines are probably more efficient than ever before. Until we get hold of them with a Power Commander that is...

So I doubt that the bike engines are any worse in general on total volume of pollutants emitted, but I can see the case for them not really being much better either.