free website stats program Optimum Outside Temp | Page 2 | Harley Davidson Forums

Optimum Outside Temp

I notice that my engine idles much smoother in 25 degree weather. Could be that the idle was a little too rich for the warmer air, but perfect in the cooler air. If in the summer time it idles smoother at sea level, rather than 4,900 feet elevation where I live, that's what it is.

For comfort, I like 75 degree weather, or 30 degree weather while wearing a Winter riding suit.
 
like jack said theres a lot of factors. i do know we never start a drag race when temps are below 45°f

That has a lot to do with the oils used for drag racing engines. I know in the old SR-2 planes the oil was almost a solid at room temp. We had to heat the oil for a couple of hours before take off to get it to actually flow through the engine, and it did not do a great job until the engines had warmed up some even then.
 
@Hoop-i kind of understand and i realize everyone is on the metric system but how about in straight american cu ft and *F. makes much more sense to a geezer. kind of like STP 70*F, 29.92, and 50%rh. i'll never catch on to metric.
 
I agree completely, I've ridden in temps down to 30f, but at that temp I'm shivering too much to care about anything except getting warm.

Come on Mainah... The last time I was on mine it was 20f... ya ok, snowmobile suit, full face helmet, and a warm truck just as soon as I parked it in storage, but the bike ran great! I don't enjoy anything below 40f but the bike seems to...
 
Today will be great for riding 70-75 degrees and the lovely Mrs. Slapp is off work, crankin up the bikes here soon and away we will go. Maybe a ride to the beaches have a nice sea food lunch.
 
Funny...my "Optimum" changes based on time of year and how I "Feel". In the winter, sunny but cold is nice...with proper gear, in the summer the same applies only now it is usually a planned longer ride, the gear and body is better adapted to the warmth by then...but now it is the "reason" to be out and about that drives how I "Feel". The bike throttles up when cold and crisp; but is still plenty happy because carburetion is still a bit rich and so am I...JUST being able to ride year around is the big plus in SoCal, "CHOICE" being the operative word here. Being near the coast or within a days ride to National parks or other locations is icing on the cake...! :D
 
Come on Mainah... The last time I was on mine it was 20f... ya ok, snowmobile suit, full face helmet, and a warm truck just as soon as I parked it in storage, but the bike ran great! I don't enjoy anything below 40f but the bike seems to...

I've ridden in cold too, but with age comes wisdom. OK, maybe not all that much wisdom. There used to be a little bike parts shop in Gardiner (Bull's) and we would ride over on New Years day as long as it wasn't actively snowing. When George closed the store and moved to So. Carolina we got out of the habit. Now with the stuff they put on the roads after the first snow there is no way I'll take the bike out till the first three or four rains in the Spring. Hope for a ride in late March or early April at best.
 
As Jack said, humidity plays a Big role in how much oxygen there is in a given amount of air. But as you can see even at temps to -13F, the density of air keeps getting larger. (This just shows how much O2 there would be in a given amount of air vs the temperature and nothing more)


Effect of temperature vs air density
Temperature Density of air
in °C vs volume of O2 ρ in kg·m−3
+35 1.1455
+25 1.1839
+20 1.2041
+15 1.2250
+5 1.2690
±0 1.2920
-5 1.3163
-10 1.3413
-15 1.3673
-20 1.3943
-25 1.4224
Good stuff Hoople......so basically colder air has more O2 in it, more O2 means a better burn up to a point. Car mechanics call it "Cold air Induction" and have aftermarket kits you can install on your car, claiming a 10-20% increse in HP. Course the better burn goes away when the humidity rises and/or the O2 is not there because of altatude.
I'd bet the reason the drag races don't start until the temps are over 45deg is because the traction on the track isn't there yet, not because of the way the cars run.
 
Back
Top