So I went on a routine bike ride yesterday, getting back at about 5. I walked in my garage at 9 and both my tires were flat! Opon inspection I realized they were both "snakebite" pinch flats.

I guess the tires weren't inflated enough and died when I hit a bump. Thing is, I noticed nothing strange on the ride. The tires didn't even cross my mind. I suppose I should check the psi before EACH ride. But are there any other reasons for such a flat? Or am I just too dumb to notice an underinflated tire?

What size are they?

Are there snakes in your garage?

700x25. Last time I inflated them I brought them up to about 110 psi. But that was a few weeks ago. Do they really leak that fast?

Heehee... I don't THINK so! But we did have a python in the backyard once so you never know.

If you have a decent pump, it takes next to no time to confirm PSI and/or top off before each ride; I don't understand why so many people neglect this.

As far as noticing an under-inflated tire, the main thing that sets of my alarm bells is when a little bounce works in to the pedal stroke. YMMV.

Yes, but a few weeks is not 'fast,' that's a long time. Top off before every ride - if you don't have a decent floor pump with a gauge, pick one up.

Pump the tires up every ride. They leak enough overnight to not be at the pressure you want, and if they start leaking more than normal between rides it can warn you of an impending failure.

Road ride? Pump up before every ride. Commuting? I pump up every week, and that's even pushing it. I generally am very careful toward the end of the week to avoid pinch flats. (Of course, this could be avoided if I just pumped up twice per week!)

Pump them up Before Every Ride.

Worked for me with 60,000 miles No Pinched flats.

I have lots of flats from road debris.

Some do, some don't.
I have had 700 x 23 tubes barely lose any pressure over a week or more, and other lose faster.
I don't usually find a need to pump up, if I pumped the day before, but after several day or more, I will check.

You can get better life/pressure retention out of a tube by taking it out of the tire and "cycling" the pressure a few times. Pump the tube up to 150 psi or so, and then let all the air out. Repeat 7-8 times. Do this once every 2 days for the first 6 months you have the tubes, and you'll notice that they will hold pressure longer. You can also lubricate the tubes with baby oil (I prefer an overnight soak) which seems to help, and it also increased my average speed.

Sometimes they explode while cycling the pressure, but that's worth the risk because it's a real pain to check the pressure with a floor pump before every ride.

This.

Oh yeah, it's WAY more hassle to check the pressure and add a pump or two before a ride than mounting and remounting your tires and tubes several times a week. Good point.

Don't *just* check the pressure before every ride. Also inspect and remove any glass, tiny rocks, and check for other damage.

Last Saturday we had a driveway blowout: I'd screwed up and sidewalled a ballast rock 200 yards earlier but the tube waited for the brakes to blow out through the cut. Dammit, another $40 tire gone. We live just on the wrong side of the tracks.

Check for snakes in your garage.

Edit: PepeM beat me to it!

Whew... do people actually do all that?

I suppose I used to deflate my sewups when not in use for more than a day or two, and pumped them up regularly.

But with my clinchers... NO!!! I regularly do a thumb pinch test on them. But, otherwise, maybe pump them up every few weeks. I do occasionally probe for glass... once a month or so, and keep an eye out other times.

The snakebite must have happened just as the OP was pulling into the garage, because that would cause the tires to flat nearly instantaneously, so there's no way they could have ridden on them more than a few seconds after the impact. Frankly, I'm surprised they didn't notice the impact, because bottoming out the rim on something hard enough to cut through the tube, both front and rear, is more than just a bump in the road.

You're missing out. The regular un-mounting and high pressure cycling of the tubes is actually kinda relaxing when you get used to it, and the post-treatment oil bath gives the tubes a pleasant scent. It also makes them more supple so that they ride like butter.

I keep a kiddie inflatable tub just for that...oh wait, you meant the tubes?

If your ride was just fine with flat tires, just think of all the money you can save by never needing to replace the tubes ever again?

I''m in the OCD club of pumping up my tires everyday before I ride.

That is what I'm worried about.

I've seen some pro video clips... it looks like they've been buttering their tires.

One thing that hasn't been covered: Pressure changes with temperature. Most people pump up their tires at home but then as they ride and the tires warm up (or cool down during the winter), the pressure inside changes. During the summer I use tire warmers and set my pressure hot. That way I always get the exact pressure I want (everyone knows it is extremely important) with the added bonus that I can start hammering right away rather than having to zig zag down the MUP to get my tires warmed up before the real action begins. During the winter I just pump up (or down) on every stoplight just to be safe.