Bicycle Mechanics - Inflate to max to avoid pinch flats?

I have been commuting to school every weekday for the past two months. It's about 15 miles round trip, with a good part of the trip on a four lane by-pass with wide side aprons safe for biking. The only problem is, these aprons are covered with sharp rocks, broken plastic and metal car parts and glass. The county road crews don't sweep them, ever. The first two weeks, I had two flats. I am running new Specialized Armadillos, which are supposed to be flat-adverse. I finally figured out I was getting pinch flats in the rear tube from running the tires under-inflated. My bike and I weigh around 230 pounds. I was running around 90 pounds, and the maximum for these tires is 125. Ever since I inflated to 125, I have had no flats. Has anyone else had this experience due to under-inflation? A side benefit to inflating to full pressure is my average mph for the 15 miles has increased 1.5 mph.

Ever since I inflated to 125, I have had no flats. Has anyone else had this experience due to under-inflation? A side benefit to inflating to full pressure is my average mph for the 15 miles has increased 1.5 mph.
Yeah, that's the real cause of pinch flats. More so with heavier riders and narrower tires.

I was running around 90 pounds, and the maximum for these tires is 125. Ever since I inflated to 125, I have had no flats. Has anyone else had this experience due to under-inflation? A side benefit to inflating to full pressure is my average mph for the 15 miles has increased 1.5 mph.

Similar experieces with mountain bikers. Lower inflation means softer ride and wider footprint, but at the risk of pinch flats. Tubeless tires (not sure if they have them for road bikes yet) allow for lower inflation pressures and no tubes to pinch flat.

And the higher the inflation pressure, the less rolling resistance, as you found out. Unfortunately, it also provides a harsher ride.

Tire pressure should be chosen based on weight and conditions... Also rims spec a max pressure...

Ever since I inflated to 125, I have had no flats. Has anyone else had this experience due to under-inflation?

I'm a religious believer of keeping pressure to the Max. Before I had pressure gauge, inflating them by just feel of it, I had many flats. The gauge cost just $10.-. Well worth it.

BTW, tubeless tires were on road bikes well before they migrated to mountain bikes :-)

Most pro riders run tubeless.

I generally run my tires just below max with good luck- a little softer ride, but firm enough to avoid pinch flats.

BTW, tubeless tires were on road bikes well before they migrated to mountain bikes :-)

Most pro riders run tubeless.

I generally run my tires just below max with good luck- a little softer ride, but firm enough to avoid pinch flats.

Are you sure, tubeless tire for road bicycles? I thought it was something new that I didn't know, so I searched a few well-known tire makers and found none of those tubeless tires were for road. I'd like to take a look at the web sites if you have the links. Aren't you talking about tubular tires?

My method of hoping to avoid pinch flats..Each time I repair a tire, I inflate/deflate a tire at least three times before riding off..I fill a tire slightly below the max. recommended level. My tire pump has a built in gauge..Seems most gauges do not.

Pro riders use tubular, or sew-up tires. There is a tube, but it is sewn into the tire casing, which is then glued to the rim. The UST tubeless tire and rim system, currently available for MTBs, is not yet available for 700c wheels.

You discovered your own answer Trm. Because of your weight you need to run at max pressure, I weigh 165 and use the same tires, but use 90 in the front and 100 in the rear. Think about car tires, you don't run car tires at max pressure either because the car weighs less then the max load carrying capacity of the tire. The max pressure rating on a tire refers to the max load carrying capacity of the tire; for example a tire may say it's max load capacity is 1,200 pounds (thus 4 tires would have a total capacity of 4,400 pounds) at 45 psi, but your car weighs 3,200 pounds thus on one of your doors there's a sticker that says the factory recommends 32psi on the front and 30 in the rear-that is the correct pressure for those tires (assuming you use the same size tires that came with the vehicle) because the car manufacture knows how much the car weighs and what the correct pressure is to ensure even tire wear. The same is tru with bicycle tires, but bicycle tires don't give a max load figure, but most tires manufactures figure the max load to be 220 pounds.

Tubular tires do not have the variety of tires available that clinchers have and therefore do not have a tire anywhere near as flat resistent as the Armadillo. Tubular tires are more suited for racing not street, commuting or touring use. Though it is true, they cannot get pinch flats.

My bad- I was confusing tubular with tubeless- definitely two different things. Sorry for the confusion!