Alox

I commute along the same route regularly, and for some reason it seems like my commute takes less time - and less energy when it's raining heavily (but calm) than when it is sunny and calm. Last night I rode home from my office in the rain, and I actually shaved 5 minutes off my usual 40-minute commute. This morning, I talked with a fellow commuter at my office, and he mentioned that he also made better than average time heading home last night.

There was no noticeable wind, and our route takes us both over a substantial hill, both of which would negate wind effects. Is it possible that:

a) water on the road reduces friction and rolling resistance on our tires?
b) raindrops of a certain size and frequency create turbulence in the air, reducing air resistance?
c) both?

bikeCarrot

Less traffic out to slow you down because of the bad weather?

JustBrowsing

You push yourself a bit more because you want to get out of the rain?

ItsJustMe

Riding faster to get the hell out of the rain?

I check my time on every ride. In the dry, my time is between 39 and 45 minutes, depending on wind. In the rain, between about 42 and 45. Really about the same, just never really fast. < 40 minute commutes aren't really common, it requires a tailwind which is almost unheard of on my ride home.

AEO

A is your answer.
lower rolling resistance.

there was a similar thread in the road section a while back, same question.
conclusion was the reduced rolling resistance.
Except this guy wanted to get even lower lower rolling resistance tyres.

chephy

I slow down in the rain for safety reasons. Especially when going 'round the corners.

unixpro

I'm slower in the rain most of the time for two reasons. First of all, I also slow down when its wet because I've put it down a couple of times taking turns on wet surfaces. Hitting the ground sucks. The second reason is that, for me anyway, the rain is usually accompanied by a headwind, at least on the longer ride home. The winds in this area come from the south and can be somewhat strong. Yesterday it wasn't too bad -- a little misty/light rain with a 5-10 MPH headwind.

noisebeam

I am always slower in the rain. I turn slower, brake earlier and slow earlier if there is a potential hazard ahead.

Al

Andy_K 

I was convinced that my old bike was faster in the rain. I eventually figured out that the rear derailer wasn't shifting right when it was wet and so I wasn't dropping down into the lazy gears I usually use.

mihlbach

I'm slower in the rain because of the heavier less aero bike, wider less efficient tires, non-aero rain gear, slower turning speeds, and more stopping distance.

If you are faster in the rain, its because you aren't riding fast enough when its dry

ShadowGray

Sure, it feels faster, considering you have the nice rain in your face feel to make you feel like you're moving at 100mph.

On the other hand, there's also the nasty wind that accompanies storms...that makes you feel like someone let the air out of your tires.

Flimflam

I don't feel any different, I do ride a little more cautiously in the rain though, as chephy said when cornering, etc.

vrkelley

+1 So don't screw it up by wearing all that heavy rain gear

deez

I'm faster in the rain. The subaru is faster than my bike anyday

I admire y'all for commuting in the rain, I don't know how I'd fare as I'm too much of a wimp to have tried as of yet. I'm kinda paranoid about the possibility of an electrical storm though so I'm generally in the car when it gets wet out.

Flimflam

You know... your skin IS waterproof, right?

charles vail

I'll ride in nearly any weather and warm rain is fine by me. I am more concerned about my visibility and my glasses getting hard to see through. My best time on my 9 mile one way commute was on my mustache bar bike and I did it in 29 minutes. I average between 35 and 45 minutes depending on my energy level and the wind. I've never noticed the rain affecting me in any major way. I do think however that the cooling effect of rain may allow a harder effort coupled with the fact that we humans tend to want to get out of rain as rapidly as possible.

BA Commuter

Resistant , not proof... I ride a little faster to get there asap. I take it a little easier in the turns, but turn it up a notch or two on the straights...

ghettocruiser

Rolling resistance is down, in theory.

Gridlock and motorist insanity is up, in practice

Tri-FatBoy

+1 I know I do.

noisebeam

Not when like this:
https://www.youtube.com/watch?v=uSOHb0lc69s

ATAC49er

CV, you sound like me! My commute WAS 9 mi. one-way 'til I transferred locations w/ my employer. Did that for years, and my personal best was 30:30. I never have really had a choice of bikes to ride, as family expenses eat up bike funds. So that commute was on a full-suss mtb 4f/4r" travel & 26x2.0 tires. Rain was always fun for me, except for the one day I didn't have my gear and got caught in a pop-up shower -- I squished at work for 5 hours!

Best hardcore commute I did to that location was in 3dg F -- took 55 minutes, and man, did it hurt! Boy, January in Indiana....

ok_commuter

I'm a little too loaded to do the math, but wouldn't it have to be an awfully long commute to for friction delta make any noticeable difference in arrive time? That sounds made up to me...

madhouse

Sorry, but I don’t buy the lower rolling resistance theory… There is extremely low rolling resistance where the tires meet the road. Tire style and air pressure are your biggest variables in regards to rolling resistance, the second being axle friction. None of these change in the rain. For the rain to affect your rolling resistance you would have to assume that your tires constantly slip on the pavement as you ride.

In fact, rain increases your rolling resistance because the trailing contact point is constantly overcoming the force of the surface tension of the water on the road. Additionally wet tires, wet bike, wet rider have more mass which requires more work to propel. The only benefit rain has on increasing speed is the human desire to get out of it!

robinthehippie

I know I go faster in the rain... no matter how nice it feels, I have this subconscious desire to get out of the bad weather. I feel like I'm a little kid being bad and playing outside when mom told me not to.

Unrelated, I've had many more pleasant experiences with cars in the rain (stopping and waving me on, not passing me over the speed limit with 6" to spare, waiting for me rather than cutting out and turning in front of me, etc.) I'm sure that shaves a minute off here and there.

CMY

Rain is easy to deal with.

Anyone dealt with fog so thick (and so sudden) that you weren't sure which way was up?