For cold weather riding - check those tire pressures!

[mrlmd1]

For those of you braving the cold and frigid wind chills with all your heated gear and multiple layers on, don't forget to check your tire pressures as the temp drops. You may be riding on 20# or less when the temps drop down to the 40's or below and although you may think a softer tire will grip the cold road surface better, that's not the case. It also may lead to wiggly steering with the front tire low, breakouts of the rear, and will lead to earlier wear. Most bikes run about 29-30# for the front 32-33# for the rear - check your owner's manual, and fill up as necessary.

[dhgeyer]

Actually, I think a somewhat softer tire does increase traction, as it creates a little bit larger contact patch, and the rubber that is in contact with the road will be more flexible (less rigid). Also, the increased flexing will keep the rubber a little warmer, and warmer tires grip better than colder ones. I agree that lowering the pressure will increase tire wear, so that's a trade off. I also agree that if the tires are too soft, it can adversely affect handling. It's a matter of degree. I would never go as low as 20 psi.

The tire pressures recommended in users' manuals vary widely from bike to bike. The GZ250 manual calls for 25 psi in the front, and 29 psi in the rear. On my Concours, a much heavier bike, the recommended pressures are 36 psi and 41 psi. The max pressure allowed by the tire manufacturer for the tires I have on the Concours is 42 psi.

Some people (including me) run their tires at a bit higher pressure than the bike manufacturer recommends, but never over the max listed on the tire. That's in good weather. This increases tire wear, and I think also gives a little better fuel economy. Some shops, when they service bikes or install new tires set them both at 40 psi regardless of the bike manufacturer's specs. They do this to increase the useful life of the tires.

In situations or conditions where traction may be compromised, I let some air out. I keep them a few psi softer in the Winter.

I check my tires with a digital gauge whenever there's a significant change in the weather, or every few days if the weather doesn't change. As a rule of thumb, every 10 degrees fahrenheit of temperature will increase or decrease tire pressure about 1 psi, although this does vary with tire size and design. Tires should always be checked cold (before riding), and most days it gets warmer later. So, if I'm checking in the morning, and the forecast is for 30 degrees warmer in the afternoon, and if I'm doing a day ride, I set my tires a about three psi lower than what I want for whatever the conditions are.

It's good advice to keep a close eye on tire pressure. I do a pre ride check every riding day before I ride, and if I'm not checking my tires with a gauge, I at least give 'em a good kick to make sure they're not noticeably soft.

[diffluere]

down here in florida the weather has been crazy! my back tire was only 13psi this morning but my front was 24. given that it was only 32 degrees this morning I left the front where it was but filled the back up to about 25. I figured after riding and the weather warming up they'd be about right. It's currently 47 here. I have one of the shitty old tire gauges that has the little stem that spits out, so I'm not sure how accurate it really is. If it's within 2-3 psi I don't really worry about it.

Over the weekend I didn't ride at all and the temps were down into the 16-17 degree range overnight, with highs of 31-32 during the day. My poor tires! I need an air compressor so I don't have to drive to the gas station all the time!

[dhgeyer]

Originally Posted by diffluere

down here in florida the weather has been crazy!

Yeah, no kidding. I read that the tropical fish farm ponds are freezing down your way, killing the fish. It must be having a terrible effect on tourism. My wife and daughter were going to go down there in January to get a break from the cold, but there's no real point right now, and it doesn't look like it's going to change before Rachael has to go back to college.

It's supposed to hit 40 here by the end of the week, and I expect to get another short (under 100 miles) day ride or two in before it turns cold again. We'll see.

How far do you have to ride to get to an air pump? If it's more than a couple of miles your tires have started to warm up, and any reading at that point won't be completely accurate. When I'm on the road, I check them cold before riding. If they need air, I note how many pounds to increase. Then, when I get to a service station, I check again, and increase the number of pounds I noted earlier from that reading.

Being also a bicycle rider, I have a bicycle pump. While I do have a compressor, it's actually quicker to put a few pounds in a motorcycle tire with the bike pump than it is to fire up the compressor, use it, and then let the air back out of the tank. You can also go to Sears and get a small, tankless compressor pretty cheaply, which will be fine for a motorcycle, or your car if you're not in a hurry. The very small compressors that come as part of roadside emergency kits (these plug into a car cigarette lighter socket) will work to put a few pounds in a motorcycle tire. I think they can be bought separately, although I never have. Some motorcycle touring folk take these and strip the working parts out of the casing, leaving a lightweight and compact package for use on the road. To do this you have to make some adjustment to the power cord, usually shortening it and putting clips or whatever on the ends of the wires to connect to a motorcycle electrical system.

Motorcycle tires don't take much air compared to car tires, and it's better to get your adjusting done cold, before you ride, for the sake of accuracy.

Some of the "stick" tire gauges are way off, and some are quite accurate. It seems to be mostly luck of the draw, and paying more for one stick gauge as opposed to another doesn't seem to make much difference in my experience. They all do seem to be consistent, though, if they are kept clean, free of grit, oil, and etc. A good strategy is to take your stick gauge, if it's in good shape (or replace it if it's not) to a tire place, and check it against the (presumably) high quality gauges they use. If it's off, just make a note of how much it's off at a few different readings, so you can do a mental calibration when you use it. Then keep it in a plastic baggie or something similar.

As a final note, if your tire was down to 13 psi, it would be very wise to keep a close eye on it for a while. Going from 70 degrees to 10 degrees should only drop it 5 or 6 psi, and you were down twice that much, so you may have a leak. Since the GZ has tubed tires, if you have a slow leak it's either got to be a slightly loose valve stem, or a small nail, brad, staple, or some such in the tire.

[Water Warrior 2]

Both of our bikes have weather proof 12 volt sockets so it is easy to pump up a low tire. They are mounted nearer the front of the bike for easy access and fused/wired directly to the battery. A compressor is cheap and easy to replace if it goes south. I carry one under the seat of the Vstrom so it is handy to both bikes.
If your rear tire was that low I would be looking for a nail or some other offending pointy thing. Sounds like you lost at least half the pressure, not a good sign and the temp drop should not affect the pressure that much.
The regular cheap tire pressure guages aren't all that bad. The ones with a square shaped plastic thingy are not bad but the ones that are a flat blade type have not been very accurate in my experience. I check my pressure guages against a very accurate dial type guage a couple times a year. Both bikes and both cages have the same type guage and all seem to be just a tad below the dial guage.

[diffluere]

The gas station I usually go to is around the corner, not even a mile away. It's not on the way I usually take to school though so it's a pain in the ass to go that way.

Anyway, it turns out WalMart has a digital tire pressure gauge for about $7. It's a lot easier for me to use than the stick one I had. They also had a little air pump for $15 that works with a 12v socket. My front tire was down to 16psi this morning but my back tire was fine. Guess I need to check for leaks. =( My poor tubes and tires aren't even 5 months old! It's only a 10 mile ride total to get to school and back and the pressure seems to hold up to that little bit of riding. I have to go back to school in about an hour so I'll check again before I leave.

After the cold snap here my car tires were down to about 24psi (normal I think is like 33) either way that's WAY below normal, not just 5 or 6 psi. I think it had something to do with the fact that it was cold for 2 weeks in a row, and I wasn't driving every day or *blush* checking/filling them up every day. Honestly I think I only left home to go to school and work the whole time, haha!

[mrlmd1]

If you just want to be able to pump up the tires at home, the old standard standup bicycle pump is by far the quickest and easiest way to do that, without all the bother of electrical connections. They are small tires and usually only take 5-10 pumps to fill them up and those pumps are pretty inexpensive and last almost forever.

[Water Warrior 2]

Originally Posted by diffluere

The gas station I usually go to is around the corner, not even a mile away. It's not on the way I usually take to school though so it's a pain in the ass to go that way.

Anyway, it turns out WalMart has a digital tire pressure gauge for about $7. It's a lot easier for me to use than the stick one I had. They also had a little air pump for $15 that works with a 12v socket. My front tire was down to 16psi this morning but my back tire was fine. Guess I need to check for leaks. =( My poor tubes and tires aren't even 5 months old! It's only a 10 mile ride total to get to school and back and the pressure seems to hold up to that little bit of riding. I have to go back to school in about an hour so I'll check again before I leave.

After the cold snap here my car tires were down to about 24psi (normal I think is like 33) either way that's WAY below normal, not just 5 or 6 psi. I think it had something to do with the fact that it was cold for 2 weeks in a row, and I wasn't driving every day or *blush* checking/filling them up every day. Honestly I think I only left home to go to school and work the whole time, haha!

Had a tire loose pressure and it was a lose valve core in the valve stem. Now I carry a complete stem and core with a valve cap that will remove a core. The sealing surface of the core is very small and will not last a lifetime. The valve stem will you no good on tube tires but it is a good place to store a valve core and valve cap.

[alantf]

Originally Posted by diffluere

WalMart has a digital tire pressure gauge for about $7.

Just make sure that it'll fit between the spokes. My digital gauge fits fine on the car, but it's too big for the spoked bike wheels, so I use a cheepo pencil type, which fits fine.

[mrlmd1]

You can get a mini pencil tire gauge with square measuring stick, only about 3" long, in many auto supply stores or Harbor Freight etc, for about a dollar, can fit on a key ring or easily stow in the underseat compartment. I have one for both bikes, no excuse not to have something handy to check tire pressures once in a while. And they work pretty well too and can't beat the price. Usually these things are near the checkout register in a bin just asking to be picked up.