Are you slower in winter?
 

I commute to work everyday. For the same effort I feel I am putting out (sometime with a PowerTap to measure so I know I am pretty close to my normal average), I am definitely slower in winter than summer, like about .5-1 mph slower. What's going on?

Yes. I don't have a power tap, but I'm almost certain I'm not putting out as much power, or putting as much effort into it.

Yes.

No matter how hard I ride, my spin bike doesn't go anywhere.

get a better spin bike

Yes. My FTP has dropped 10% since September. I'm hoping that some of that loss is due to the most recent test being done indoors (versus the prior being conducted outside), and after a 2 week lafoff including a light head cold.

No. We are all faster all the time.

Yes. I'm pretty sure it has something to do with the 10lbs I gained over the holidays.

It's the drag of extra clothing layers.

I go faster, I use it to warm up my freezing body.

the air density being that large of a deterrent is very interesting.

either way i feel much slower commuting during the winter months.

My century rides take longer so I spread them over several days. It still counts, right?

Ha!

If I was any slower than I am in the summer, I would fall over

Wrong thread.

Definitely slower. A lot of it is just the cold, I think, but the studded winter tires don't help.

Cold, dry air is denser and can easily drop 1kph from your speed at a given power. Also fenders, mudflaps and bulky clothes don't help.

I haven't ridden a road bike for enough years to really tell.

Oh wait, this is BF? Yes, I am slower, definitely, by 0.75-1.25 mph.

I am much slower. My average in summer is 18 mph, in winter 15-16 mph. I guess because I get older every winter

Slower here, too. I adhere to the "denser air" theory. Seriously, I go a lot faster in hot weather; noticeably slower (1-2 mph on average) in winter.

My winter beater bike is about 10 lbs heavier then the unsalted roads warmer weather bike. Plus the winter winds seem to be a lot harder to push against and the slush at the side of the road is difficult to pedal through, etc.. Yes.

I'm not slower on warm days.

Compared to ?

This is a cool read... as at least it validates that I didn't suck more in winter.

There's also the wind chill thing - the faster you go, the colder it feels. Makes you think twice when you feel the urge to drope the hamer.

I would love to "drope the hamer"

drope http://www.urbandictionary.com/define.php?term=drope
hamer: http://www.urbandictionary.com/define.php?term=hamer

Here in South Bend IN I am about 1-2 mph slower in the winter. The colder it is, the slower I go. Part of it is the increased weight- of fenders, lights, lithium batteries, additional clothing etc. Part of it is increased resistance to pedaling from all the crap I am wearing. Part of it is the snow and ice on the roads. my down hill runs are slower and my turns are slower from caution in cornering ( went down last night on an invisible patch of ice at night). And most importantly increased air density and hence resistance. Warm dry air in summer is roughly 1 atm pressure. At 10 degrees F it can be up to 1.4 atm, an increased density of 40 %. Here in Indiana the winds are stronger and the protection from foliage is also less. Lot's of reasons to be going slower. But it's still way, way, way better than riding on a trainer indoors.

I'm always slower, it's just a matter of degree.

the temperature remains constant in the 41, hence my average posted speed remains constant

I have evidence of the increased bearing resistance phenomenon.

The SRM data from rollers sessions in my (sometimes 45˚) training room show that between cold-start and twenty minutes into the ride, the power requirements for the same spin speed go down by 10 or 15 watts as the bearings warm up.

This happens again if I take as little as 5 minutes rest.