Wheel bearings freezing?
 

On my commute to work today in Toronto (-10c), I noticed after about 15 minutes of riding, when i start coasting and then repedaling again, it would take a bunch of rotations until I can start moving again. It's the exact same feeling when your chain pops off. Is this because my back wheel bearings are freezing up? Has this happened to anyone else?

Hmmmm...

Bearings shouldn't, actually can't freeze, they're metal. But the grease will thicken considerably in cold. But that's a bit much at those temps. Alternatively, if they haven't been greased in a while, any moisture would freeze. I've had this with sealed (lined) cable systems.

I'm grasping at straws, really.

Your freehub pawls are sticking.

The problem is usually caused by the presence of grease, rather than it's absence, and at -18C or whatever it was this morning the grease gets thick enough to keep the ratchet from engaging. It can also happen to really old freehubs where the pawls are wore down.

I guess it could theoretically be water in the freehub, but you'd notice this at -1C or so

You can either have the freehub repacked with low-temperature grease, try another, older back wheel that might not have much grease left to thicken(if you have one) or just assume it won't be -18C again anytime soon. My vote goes for the later.

Yup, this is a freewheel/freehub problem. You could take the nozzle of a WD-40 and shoot it in there and it will solve the problem in about 3 seconds. However, WD-40 is a heck of a solvent and if it gets in your wheel bearings they will shortly be toast. So, take the time to remove the freewheel/freehub and then hit it will the solvent, let it dry out, and then try to drip light oil in there. Bolt it back up and you will not have to worry about it for about 10 years.

jim

+ 1 for the wd40 treatment. Has kept me rolling down to -15F/-26C.

On my bike I lay the wheel down, shoot the wd40 into it, spin the freewheel, then turn the wheel over to let the extra drain out the front.

Be very careful with that method. Keep in mind that there are lots of nooks and crannies in there for the solvent to pool, and then get spun out when you ride. I do not mean to sound hysterical, but even a dab of solvent in your bearing grease will cause lots of havoc.

jim

We had -10F this am and mine froze up I warmed at a stop inside and got close to home but will need to do above. I am think of trying this (on the removed FW) Squirt in my chain lube mix with an eye dropper. I mix up 1/4 motor oil and 3/4 mineral spirits. Think this is a good approach? I was riding one speeds all winter, just junkers. But in my old age the hills are getting steeper.

Yes, my mountain bike has same symptoms when colder than -15C or so. It is rather annoying to have the pawls stick open and I end up cycling in a way to continuously keep the gears engaged - even braking on downhills. This morning was -20C, but we don't get that temperature very often here in Fort Collins so I've been making do on those occasions.

I must be a freak of nature, because I can ride down to -30C on my walmart bike (albeit, not a 27 speed, fully suspension junker) without any perceivable problems to my drive train.

Sounds like a rusty bearing to me. I've found that grease only thickens up at temps below -20c, usually -25c and colder. It's also been my experience that when grease does thicken up at these temps it usually heats up to normal after a few minutes of riding.

BTW, what hub is it, and does it have loose or cartridge bearings?

Check out the IceBike article on Winterizing a freehub.

I don't know why anyone hasn't mentioned what I do. All my bikes, I take out the old grease, clean the hub races and bearings with a solvent, and regrease using only synthetic grease. It doesn't get thick like regular grease. I also use synthetic engine oil and differential oil in my car's differential and transfer case.

I agree it's a freewheel/freehub problem, and the WD40 will work, but try a light chain oil first. Something like Prolink might do the job without the risk associated with WD40.