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Newbie tip of the day: When bike is spending the day inside a closed car...(13 posts)

Newbie tip of the day: When bike is spending the day inside a closed car...Kristin
Sep 26, 2003 7:23 AM
Let about 1/2 of the air out of the tires.
maybe I'm just lucky...mohair_chair
Sep 26, 2003 7:47 AM
I've always believed this is a myth. I live in California (where it gets hot, hot, hot), leave my bike in the car a lot, and I never let out any air.

Even if you dig up Gay-Lusaac's law relating temperature and pressure (assuming volume remains constant) and prove to me that the pressure increases with the temperature, I'm not convinced it's a problem, because I've never had any problems at all. Gay-Lusaac's law assumes the volume remains constant, but I doubt it does (the tire expands), which is probably the difference.

You also forgot the corallary newbie tip: if you let out 1/2 the air in your tires, make sure you bring a pump if you hope to ride.
I have noticed this though...Zman
Sep 26, 2003 8:01 AM
Hey Mohair, you are one tough crowd!

Anyways. I live in St. Paul and venture to the highlands of Colorado at least once every year. On my mountain bikes I use Hutchinson Air Lights at 60 psi. When I get to Breckenridge or Purgatory the air pressure is definately MUCH higher. I need to let out the air, and then air up when I get back. No big deal because I check air pressure on EVERY ride I do, just a observation.

My potatoe chip bags usually explode also!

blowed up, sir!!!gregario
Sep 26, 2003 8:23 AM
I remember sitting in a meeting at work with my van parked outside and my tandem sitting inside it on a hot day. For some reason I forgot to let some air out of the tires. Sure enough, I heard the bang from inside the building. This was Michigan, not Arizona.
LOL! Loved the Stripes reference. NMgtown
Sep 26, 2003 8:52 AM
glad you caught it. I declare you above average (nm)gregario
Sep 26, 2003 9:10 AM
I have 3 innertubes and a wheel barrel that say you're wrong!Kristin
Sep 26, 2003 8:57 AM
I'm no scientist, so I couldn't say why, but I suspect that road tires are less suseptable to this than MTB tires.

Case #Uno. One 23mm, 700c tire left to bake in back seat of car on hot summer day. Arrive at group ride to find tire deflated. Tube has tear along a seam. I've left the road bike in the car many, many times and it this has only happened once. (I typically keep my road tires at 110 PSI.)

Case #Deux. One 2x26 tire left to bake in back seat for 4 days. Finally remove bike from car for a ride. Flat rear tire. Replace tube. Rinse. Repeat. That's 2 tubes that never saw more than my beigh uhpolstery. Both tires have large tears along a seam. (Both tires were pumped to 60 PSI in a 75 degree room.)

Case #Tri. One 4x10 front wheel barrel wheel transplanted from -25 degree atmophere to +60 degree atmosphere at 1500' elevation. One family of 4 searching house at 3 am for cause of explosion.

I'm sure that there are several things that can increase or decrease the risk of a tube blowing. What tempurature was the air in the tire when it was placed into the car? How hot did the car become? What material and desity are the tubes? Who much PSI is in the tire? What elevation?
Another corallaryBulldozer
Sep 26, 2003 9:40 AM
When transporting a bike on a trunk-mounted rack, do not position either tire close to the exhaust.

A friend of mine and myself were driving up I70 here in Colorado to go riding in Evergreen. As we were motoring up one of the steep hills we heard a loud bang. We presumed that it was the beat up pickup that we were passing at the time. Come to find out, the exhaust had blown my friends slimed tire all over the back of his Honda.

Sub-corallary - tube slime does not come off cars very easily after exploding.
I just let out about 20 pounds, just to be safe.MR_GRUMPY
Sep 26, 2003 7:57 AM
One thing that I have discovered, is that if a tube has been patched, the high heat, inside of a car, can cause the patch to come loose. I'm not sure why this happens, but it has happened 3 or 4 times to me.
Take the computer with you . . .ms
Sep 26, 2003 8:13 AM
I left my bike with a Shimano Flight Deck computer on it in the car on a hot (high 90s) sunny day. The heat in the car fried the computer's brain -- it initially appeared to work, but would skip functions, misrecord data, etc. The owner's manual warns about subjecting the computer to high (120+) temperatures. Of course, I did not read the warning until it was too late.
don't pump them up so much to begin withContinental
Sep 26, 2003 8:45 AM
If you only put 90 to 100 psig in your 120 psig rated tires to begin with,they won't explode in the heat of the car. Also, 90 psig gives a smoother ride, fewer flats, and better control on rough roads. I'm with Uncle Al at on tire pressure. Most people run too high of pressure for the way they ride.
Found this out more than once the hard waybimini
Sep 26, 2003 8:48 AM
I lost air twice by leaving the bike in the trunk on hot days before I knew what was going on.

First time was almost a disaster. Pulled the wheels out of the trunk, rear was flat. No big deal. I just slapped in my spare tube pumped up and started my warm up. Then 20 minutes later Kaboom - In my haste I didn't check for a pinched tube and the new tube had a 12" slit in it.

Had to pick up the bike and run back to the car. No more tubes. I was in a panic and then it dawned on me. Use the other wheelset stupid. Got the new wheel on 5 minutes before the start of the race. (glad it did not happen during the race)

Had another wheel flat in the trunk at another race. Then I learned to let some air out. (and carry 2 spares)

I like high pressure in my race wheels and have a black car so I am sure this caused the flats.
Also please remember to crack the window just a bit.djg
Sep 26, 2003 9:18 AM
So it doesn't suffocate.