My bike loves the cold dense air of autumn....

[DucDave]

Just took a spin. Temp was an indicated 35 degrees. Sky was clear but there was some wind. Most roads were leaf free. In a few more weeks all the leaves will be off the trees and clear of the roads. Sightlines improved. My favorite time of year to ride.

I'm sure there's a calculation that would tell me what sort of HP increase I see between 80 and 35 degrees. It feels significant!!!

[DaveZX6r]

I just got back from an after work scoot myself Dave. Its beautiful out there. I always forget how awesome it is to ride in the fall.

[RandyO]

It feels significant!!!

there's no question, the free HP you get from cold air is significant

my SV650 that needed some clutch to loft the front wheel in 1st or 2nd gear in summer 90° temp would get a 3rd gear roll on wheelie at 20°l

[obsolete]

Density Altitude correction.

http://wahiduddin.net/calc/calc_hp_dp.htm

[FAST GSXR750]

My 81 650 loves cold dense air. But then again i'm kinda cold and dense myself.

[xrocket21]

horsepower air, LOVE IT!

[PhilB]

My old Alfa Romeo was like that, too. It loved the fog -- it top speed was literally increased by 10 mph in heavy fog, from 115 indicated to 125 indicated.

PhilB

[01xj]

My 81 650 loves cold dense air. But then again i'm kinda cold and dense myself.

I think your mixing up "kind of old" and "kinda cold"

[Ducatijocki]

Driving 125 mph in the fog!

[PhilB]

Driving 125 mph in the fog!

Yeah, well I was about 20, so still young and dumb. I did try to make it as safe as I could. I had noticed that the car just felt a lot stronger in the fog, so I wanted to find out. I went out to a very empty freeway at about 2AM, with a friend in another car. He drove well up ahead to make sure the road was clear, and if he came up to any other vehicle, he was to slow, wait to see my headlights, and flash his brake lights repeatedly to warn me to call it off. As it turned out, the road was clear on the first pass. It was pretty scary, though.

PhilB

[ZX-12R]

I love down hill power wheelies in this weather.

[obsolete]

Yeah, well I was about 20, so still young and dumb. I did try to make it as safe as I could. I had noticed that the car just felt a lot stronger in the fog, so I wanted to find out. I went out to a very empty freeway at about 2AM, with a friend in another car. He drove well up ahead to make sure the road was clear, and if he came up to any other vehicle, he was to slow, wait to see my headlights, and flash his brake lights repeatedly to warn me to call it off. As it turned out, the road was clear on the first pass. It was pretty scary, though.

PhilB

Ahaha that's what you did to go 125 and call it young and dumb lol. You have no idea what young and dumb is.

[sveesix]

As does the Tiger.

[golden chicken]

It can be a bit of an adventure to balance free power against cold pavement and cold rubber.

[gregp]

My DR650 is certainly one of those "cold weather" bikes. The air/oil cooled motor runs pretty hot in the summer. The lean factory jetting requires a bit of a warm up, though. Then it is happy all day long.

[markbvt]

My Tiger is liking the cold, dense air too. Getting much worse gas mileage though... but that's mostly because they've switched to the winter-blend gas.

--mark

[obsolete]

What is the difference in summer and winter blend gas?

[B440]

What is the difference in summer and winter blend gas?

http://lmgtfy.com/?q=What+is+the+dif...nter+blend+gas

[obsolete]

http://lmgtfy.com/?q=What+is+the+dif...nter+blend+gas

Thanks

[TheIglu]

Vmax pulls harder when it's about 60 degrees out, seems not to pull as hard in the low 40's like last night.

[obsolete]

Vmax pulls harder when it's about 60 degrees out, seems not to pull as hard in the low 40's like last night.

A complete guess here but since a carb has a fixed metering of fuel could the addition of more o2 lean it out and lose power?

[OreoGaborio]

A complete guess here but since a carb has a fixed metering of fuel could the addition of more o2 lean it out and lose power?

That's my guess.

Back in my flying days we had a mixture screw. We would use that to change the a/f ratio to compensate for the changing density altitude.

[RandyO]

according to this site ( its on the internet so its gotta be true) there is a 1% increase in HP for every 7.2°F drop in ambient air temperature

that's a 7% increase in HP difference from 80° to 30°

[OreoGaborio]

IF you can adjust for density altitude?

[NobodySpecific]

Went to pass a car that decided to pull up next to me and match my speed going into a merge, forgot that it was brisk out, and promptly pulled a squidly wheelie in the middle of traffic. Liter bike - 1 tooth + cold air = wheelie monster.

Edit: mind you I pulled this wheelie with a huge Givi topcase and a dorky looking 3/4 length jacket.