rumrunn6

so last night I had my bike up on my outdoor stand (car rack on rear deck railing) to check the brakes; shifters and wheels. the temp was 10 degree F a good 20 degrees below freezing. I noticed my rear wheel didn't spin very long before stopping on it's own. I thought a brake pad was rubbing but it wasn't they are still functioning properly, a little sluggish but operating. I guess the bearing grease is pretty think at these temps? the front wheel spun a but longer than the rear. anyone else observe this? I wasn't planning on servicing the bearings this winter. I don't ride a lot and it seems less and less. didn't get out for more than .5 mile on Monday when I had to turn back due to black ice everywhere. plotting my purchase of studded tires ...

Pig_Chaser

Well grease does thicken up. I haven't noticed it too much though until temps reach about -30c, then my average speeds plummet and it literally feels like my cranks are fighting back.

mikewille

Synthetic grease remains greasy at lower temperatures

rumrunn6

I store my bike outside under a tarp. Does anyone else? I don't notice any slowness riding it - jut when it's up in the air and I'm manually spinning the wheels.

tjspiel

Do you have a quick release? If so, loosen it and see if the wheel spins any easier. Maybe the change in temps has affected your bearing adjustment.

I don't really know if my wheels spin any slower in the cold but I wouldn't be surprised if they did.

TRaffic Jammer

It's the bearing grease freezing up , no biggie. With you on it, it'll be barely noticeable, though pedaling will feel sluggish.

hshearer

I bet 65er has the answer to this one, and if he's reading, I'd like to know what grease he recommends. I'm with PigChaser. Around -30C, it's just hard to move. Seriously; my speed drops off dramatically below -20C, much more than air density would account for. Same clothes, same bike, and if anything, more effort because I'm embarrased by how slow I am (as if anyone cares). I go about 15 km/h for more effort than I'd put out doing close to 25 km/h if it was just a little warmer.

I thought new grease was the answer, too, and so I cleaned out one of my headsets and replaced the grease with Dumond tech (it's a bluish-green colour), recommended by my LBS as the best grease for low temps. There was some improvement, since the headset was filthy, but it still gets noticeably stiff below -30C, and stiffens up at about the same point as another bike I used to ride in winter that still has the factory grease. Cranks are hard to turn, shifting is sluggish to non-existant (and not from frozen water... nothing is even coming close to melting in the first place). Wheels don't turn easily. Rolling resistance from tires might be a factor, too, when it's "square tire" weather. It's like riding with your brakes on. I don't think I'll bother with the bottom bracket and hubs unless I find myself with a ton of time on my hands (unlikely). I'll just consider it to be resistance training.

The headset is worth keeping mobile if you're out in super-cold (approaching -40)... it's kind of important for your balance, and you might not notice how stiff it is until you need to steer... and can't.

TRaffic Jammer

There's got to be a special Arctic grease out there.

rumrunn6

I'll consider the cone adjustment for the rear wheel. I'll also check it after a ride and see if the friction and warmth of friction has loosened up the peanut butter sensation.

CastIron

You could always switch to Mobil1 90w gear oil. Full synthetic and lighter than grease (but not much). A PITA, though. I've had good luck with a synthetic Finish Line grease.

silver_ghost

DumondeTech is described as a "liquid polymer" that supposedly stays slippery when grease starts to solidify (I bet I know which shop you go to, hshearer). I definately notice my wheels spin longer when unloaded with Dumonde in the hubs, but I'm not willing to bet my life on that decreased resistance being noticeable while riding.

You're probably onto something with the "square tire" idea. Also, tire inflation is often a huge contributor to overall efficiency and tire pressure will vary with temperature. If my meagre grasp of chemistry holds, inflating your tires indoors and then going outside at -20C will result in a 10psi loss in pressure.

TRaffic Jammer

....and the air is like cough syrup in density compared to a warm summer's day air density. It's harder to breath in making any exertion seem harder. Many factors make workin' it in the winter more work. Frozen tires suck it bad.

AEO

my new guess... the tires don't deflect as much as they do in warmer weather.
rolling resistance is related to how much the tires deflect on the road, obviously cold weather will stiffen the rubber, leading to more rolling resistance.


I really wish I could figure out the cause too, since I just feel super slow when commuting in the cold. (although, mind you, I'm only about 2~3mins slower in the cold, compared to 45min journey warm days)

other contributing factors (guess)
stiffer body joints
denser air
more upright position
knobby studded vs. slick
more energy spent on keeping warm
windier
all roads have an additional 5% gradient to them compared to summer

hshearer

Air density at -30C (70% r.h. and 100 kPa) = 1.4308 kg/m3

Air density at -20C (70% r.h. and 100 kPa) = 1.3716 kg/m3

I don't think the change in air density is enough to account for how much slower I am at -30C vs. -20C. Same bike, same clothes, same happy rider. It's a very abrupt and noticeable change (I certainly don't notice as much difference in speed with a change from -10C to -20C, for example). The only other thing, besides air density, that could have changed between those temperatures is resistance from moving parts; either the grease or tires have become too stiff, maybe both, but I feel like it's the grease gelling, just because all the moving parts are sluggish.

Anyways, in winter it's not (usually) a race, so slower speeds just make for more time on the bike. Figuring out why is kind of interesting, though.

@silver_ghost... Bike Dr. The Dumonde tech sounded like as good a lube as was locally available, I agree. The "I'd ride my bike when it's 40 below" group of nuts is a pretty small market, after all. I was glad they even had a product to recommend. My headset still swivels, so I'm happy! I bet if I replaced whatever grotty grease is in my hubs and bottom bracket with the Dumonde, I'd be faster in that extreme cold range... of course, I'd then probably have to do an even better job of getting dressed due to the enhanced windchill.

tjspiel

I can't put my finger on an exact temp, but at some point in the -10 to -25 F range, airplanes passing overhead sound much louder.

rumrunn6

I am too dense to comprehend this

TRaffic Jammer

Not to mention it's harder to breath it in as well as move through it, making the effect even more noticeable. Add the added sluggishness of cold grease and frozen tires, serve cold.

chipcom 

So the grease in the bearings thickens a bit in the cold and the wheel turns a smidge less freely. Unless you are trying to shave milliseconds for a TT, or it takes too much effort to turn the wheel, why worry about it?

ghettocruiser

I like this guy.

LarDasse74

I have always attributed bike slowness in extreme cold, in part, to thick grease. I have ridden in temps as cold as ~-40(C or F), and my bike feels damn slow. Partly this might be my bulky clothes, and partly due to increased difficulty breathing through a balaclava or scarf... but the bike is slower when coasting, so there is something mechanically slowing the bike down independent of my personal weaknesses.

Last week I had my Alfine IGH bike out for a ride at -25C and goddamn did it ever feel slow! I think I could even feel some notchiness for the drivetrain I did not notice before. This tends to support my hypothosis, as the complicated innards of an IGH are more susceptible to drivetrain friction, and just as susceptible to bearing frinction as a non IGH bike.

Fissile

Went out last week in 20 degree weather, and the drivetrain felt sluggish, almost sticky. I was using motorcycle chain lube in the warmer weather. I removed the chain and washed it in solvent. I then oiled it with Mobil 1 5-30. There was a noticeable improvement. Moral of story: In very cold weather, use synthetic lubricants instead of dino based stuff.

rumrunn6

interesting

rumrunn6

the bike has been in my garage for a week, and it's been warmer than freezing. I miunting some studded snow tires and so I had the wheel off and too a closer look. it was still "gooey". without backing off the cones, which felt fine to the touch I sprayed some oil (not wd40) into the hub on both sides and worked the axle back and forth ans spun it a little. it feels like it lossened up but just slightly. I'm gonna keep an eye on it - it could be due for a servicing and fresh grease.