Bike's faster in the cold

Ant · World Chat Champion Joined: 24 Feb 2003 Karma :

well today i went out on the bike for the first time in 3 or 5 weeks and it seemd faster! Confused

Is it that i'm used to the Power of my escort van or can a more mechanicly minded person explain to me?
And has anyone else noticed this?

Cheers
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r1_lad · Spanner Monkey Joined: 05 Aug 2004 Karma :

I think the coldness of the air does make a slight differnce.
Something about colder air being denser.
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mchaggis · World Chat Champion Joined: 10 May 2004 Karma :

When it's cold, the density of the air is higher. This means you can get more mass of air into the cylinders, so you can burn more fuel. Result equals more power.
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Retro-Man · Traffic Copper Joined: 21 Aug 2004 Karma :

correct first time cold air is denser and as such has a higher oxygen content per litre, extra oxygen in the piston chamber increase burn and hence power output is slightly up
Thumbs Up

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paulodd · Crazy Courier Joined: 20 Oct 2004 Karma :

my bikes been going slower since last tuesday Sad

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1999 Yamaha R6
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Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Yes cold air does mean more power, but I doubt you would notice the difference consistanty over several weeks of not riding it.

I suspect that it is just the shock of suddenly using a vehicle that responds to the throttle.

All the best

Keith
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DM · Scooby Slapper Joined: 16 Oct 2004 Karma :

Unfortunately, if it's too cold then the drag from my winter jacket negates any power increase I was getting Crying or Very sad

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aqualung1 · Trackday Trickster Joined: 15 Jul 2004 Karma :

thats also why when on a really hot summers day the bike will sometimes feel yuk, come the cooler evening will run best

its also why some spring autumn runs seem best
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instigator · Super Spammer Joined: 19 Oct 2004 Karma :

Retro-Man · Traffic Copper Joined: 21 Aug 2004 Karma :

TheShaggyDA · Repost Police Joined: 14 Jun 2004 Karma :

I remember seeing on Tomorrow's World some years back they had 2 cars running with a pint of petrol, one normal and one being treated as though it was running in fog - the latter returned more mpg.
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NickD · World Chat Champion Joined: 20 Aug 2004 Karma :

As daft as it sounds, your brain processes information more slowly when you are cold, so your peception of speed may also change.
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yambabe · World Chat Champion Joined: 12 Jul 2004 Karma :

Well I KNOW my bike goes faster in the cold cos I want to get where I'm going quicker so I ride faster...... Razz

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haGGard · Nearly there... Joined: 13 Oct 2004 Karma :

map · Mr Calendar Joined: 14 Jun 2004 Karma :

Bad news is cold air/wind chill can give carb icing!
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Rory · Traffic Copper Joined: 14 May 2004 Karma :

There's also an added cooling effect on your engine, and if the air is damper, the water vapour acts like an octane enhancer.
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jay12329 · Dr. Evil Joined: 02 May 2003 Karma :

When its cold I am cold, so i want to get to wher ei'm going faster, so i ride faster. My bike is defenatly faster in the cold, but tis not due to the small difference in air dencity.
J

TheShaggyDA · Repost Police Joined: 14 Jun 2004 Karma :

isn't that what Babyyam just said?
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[i:6e3bfc7581]But still I fear and still I dare not laugh at the madman...[/i:6e3bfc7581]

Rory · Traffic Copper Joined: 14 May 2004 Karma :

mrchips · World Chat Champion Joined: 05 Mar 2004 Karma :

I think I will strap an industrial strength fan to my forks.

mchaggis · World Chat Champion Joined: 10 May 2004 Karma :

mrchips · World Chat Champion Joined: 05 Mar 2004 Karma :

Then I'll stick a K&N on too... that ought to work.

Ninja · Caption Abuser Joined: 22 Apr 2004 Karma :

Rory · Traffic Copper Joined: 14 May 2004 Karma :

mchaggis · World Chat Champion Joined: 10 May 2004 Karma :

https://www.bikechatforums.com/viewtopic.php?p=328611

See this thread for details on water injection. It has the same effect as a higher octane rating fuel, which in power terms is nothing without altering the compression ratio and ignition timing.

Advance the ignition timing and you will be more prone to knocking as the burn is too fast. Add a small amount water/ water and methanol, or use higher octane fuel, and you can use further advanced ignition, without knock occurring. Advanced ignition timing = more power, up to a point.
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