Cold weather pwerformance
 

Just wondering if anyone else notices that their performance drops when the weather gets cold and then in Spring they get it back. I tend to lose 2kph on average from warm to sub freezing temps.
BTW, I'm riding in 25F temps.
Thanks

The cold amplifies the batteries IR (Internal Resistance).
This demonstrates as deeper voltage sag, delayed "plate" replenishment, reduced power and a premature "empty".
Combine this with the motors increased IR and the thickening-stiffing of all lubricated parts and you have a substantial performance deterioration.

Keeping you battery warm is the easiest partial "fix".

Insulating the motor is a dicey proposition.
If only used for brief trips, keeping the entire bike warm helps ... unless your braking surface, melts snow then freezes on a layer of ice.

DrkAngel, I believe you are talking motorcycles. I generally keep those stored inside during the winter unless it is a particularly nice day.
I was referring to bicycle riding performance and my body`s inability to push my bike at the same speed in the winter as in the warmer months.
But, if you want to talk motorcycles, feel free to PM me! :thumb:

By now every winter im a little slower, this is my 65th one.

Lots of factors contribute to slower riding when it's cold and I'm surprised you only see a drop of 2 k/hr. They include:
1) denser air when it's cold - therefore greater air resistance
2) more clothing which restricts the movement of your legs and also adds air resistance
3) colder air in your lungs results in slower exchange of oxygen into your blood
4) body uses more energy to stay warm so less is available for leg muscles
5) more mechanical resistance when cold due to thicker grease/oil in bearings and less flexible rubber tires.

Thanks for the excellent info, prathmann.

x2. That's good insight, prathman.

I rode 60 miles this past Saturday; I felt much more beaten up than usual. I hadn't thought that my body would use more energy to conserve warmth in the cold.

I figured that the denser air would have more atoms of oxygen per cubic inch then “normal” tempature air (59F)
Youd think the harder/less flexable tires would decrease rolling friction though.
But I guess those other drawbacks decrease performance more then the extra oxygen and decreased tire resistance would increas it.
Great for airplanes though as long as you keep the ice off!

If you have not noticed, your heart rate jacks up much higher than normal in the cold. It is amazing how hard your body works to keep warm.

Same in the hot summer with your body working harder to keep cool.

You can train around this to some degree and improve a little.

My MD co-workers say below 20, there is not much exercise benefit from riding.

2) has more impact in my mind especially when wearing unstretchable pants/tights on the knee area.

4) It would be true if our body was a closed system but as everybody knows we can eat and drink and breath more when needed and our body can make glucose via gluconeogenesis.
There is definitively something there though. I believe that probably there could be as many different outcomes as people.
What is known is that blood pressure increase when the body get colder and that blood pressure can decrease after a time of exposure to hot temperatures but is also higher first.
http://www.colorado.edu/eeb/courses/...%202007/17.htm
But because we wear more clothes in winter, more clothes usually means than it becomes harder to regulate the temperature well and it also means possibly that clothes could generate more compression on the body parts so depending on each and every one of us outcomes could be everything between hyperthermia and hypothermia, restricted blood flow or not.
Futhermore, lack of blood flow should lead to less nutrient and oxygen to the muscles leading to lower performance in winter but one study has shown that results could be the opposite temporarily depending on training. So there is no way to know the outcomes for everyone.
http://www.wired.com/playbook/2010/1...econditioning/

No, the harder rubber in the tires when they're cold will still flex - if you pump them up to 100 psi and load each tire with 100 lbs., then the tire will flex until you get a contact area of about 1 sq. in. But when the tire is cold it'll take more energy to do that flexing and therefore the rolling resistance is increased. You want tires with very supple, easily flexed sidewalls for minimum rolling resistance.