If you’re new to winter cycling, or newly considering it, check out to those links first! The information in the rest of this post is mostly technical trivia: tidbits of information that are interesting to think about for tinkerers, but not especially important to know just to enjoy your experience with cycling in winter.
Temperature and Tire Pressure
People often ask: “As the temperature drops, will my tire pressure drop?”
Short answer: not enough to worry about.
Longer answer: yes, but it’s almost certainly insignificant. For every 10°C that the air temperature drops, you lose 3.41% of your starting pressure at 20°C (regardless of the actual value of your starting pressure or your tire’s nominal volume).
e.g. If you start at 100psi at 20°C, then you'll be at 96.6psi at 10°C, 93.2psi at 0°C, 89.8psi at -10°C, and 86.4psi at -20°C. And you'll have 103.4psi at +30°C.
So if you inflate your tires at 20°C and then go for a ride at -20°C, you'll lose 13.64% of your room temperature pressure.
If your tire was inflated to 55psi, that would mean it drops down to 48psi. If you’re riding a fat bike and you had inflated to 10psi indoors, at -20°C, it would drop to 8.6psi.
For most of us, even this 40° change in temperature isn’t very significant. That is: if you don’t want to care about it, you don’t need to. If you do want to care, you now have the math to care very precisely!
Note that the rubber of a tire can also harden at cold temperatures. Winter tires are more forgiving here, thanks to being a softer rubber compound, but all tires will become more stiff and won’t roll as well in extreme cold.
Does grease get thicker in the cold?
It sure does. Temperature sensitivity depends on your particular lubricant, however. Some fare better than others. We haven’t conducted extensive testing ourselves, so don’t have specific recommendations, though many greases will have published technical data sheets that specify their temperature range.
We tested a standard bike grease (no temperature specs were available) at -26°C and found it became more viscous, but was still malleable. We also tested a high-performance grease (rated for -29°C to +293°C), and it was stiff as cold taffy, despite still being within its specified temperature range.
What does this mean for me and my bike?
It means that things may get sluggish and unresponsive, and pedaling might take a bit more work. However, changing out the grease in your hubs and other components is a significant amount of work (and, for some components, not feasible at all), and we don’t currently have any particular suggestion of an ideal grease, so basically: just accept it. Or run a test of several greases yourself and let us know your results, and we’ll update this page.
Many people will experience sluggish or unresponsive shifting at the temperatures we’ve been seeing recently (both with external derailleurs and with internally-geared hubs), and freewheels and freehubs that stop engaging and instead freely spin while you’re trying to pedal forward (i.e. cranks turn, but the wheel doesn’t, similar to backpedalling). This is due to pawls in the ratcheting mechanism becoming frozen, and not springing back to engage. A simple trick: lift the rear end of the bike off the ground a few inches and then bounce it down on the back wheel. This can often shock the pawls back into action so you can keep riding a bit farther.
A reality check, though: in the past 10 years, Edmonton saw an average of fewer than 2 days a year where we reached -30°C, and then it was usually only for a couple hours in the very early morning before warming up during the day. Recognizing that during the coldest month of the year (January), the average daily high is -4°C, you really don’t need to focus your life or transportation around one or two days of the entire year.
For those times when it gets really cold, embrace it and enjoy the fact that you’re burning a lot more calories, or you can just take the bus or drive until it warms up again in a few days. Both are perfectly reasonable options.
Some times locks can become finicky in the cold. We have dry powdered graphite lubricant at both of our workshops that you can come and use. If there’s a lot of corrosion, you can try adding in a few drops of a liquid lubricant such as Triflow as well (which we also have at our workshops), which will help move the graphite deeper into the lock and get things really moving well again, and prevent further freeze-ups, even in the coldest weather. Beware of using too much, however, as it will mean that every time you pull your key out it will have a coating of graphite and Triflow and can stain your clothes!