Have a flat?
Problem: The only way to 100% avoid flats is to not ride your bike.
Solution: keep riding your bike and follow two simple instructions.
For over 30 years we have tried and seen almost every "flat-proof" product out there. What we have learned is that flats are not completely avoidable. Just like we can still get a flat on our $300 car tires, our best solutions for bicycles aren't 100% perfect.
So what have we found? With a couple of high-quality products and some common sense we can ride with a heck of a lot of assurance.
1. Swap to Specialized Armadillo tires
Since the 1990s the Armadillo model tires from Specialized have set the standard for flat-protection. Kevlar is added to the entire tire casing and a proprietary Kevlar/polymer belt is placed under the tread. This cut and puncture resistance layers provide flat protection from bead to bead. Although not fool-proof, it works exceptionally well for stickers, thorns, goat heads, and small nails and screws.
No liners or extra-thick tubes are normally needed.
$45 per tire is well worth it! Consider fixing a few flats at $8-12 per tube. These tires have saved our customers many many rides and a lot of money. Sizes are available to fit most bikes.
2. Use TruGoo sealant in standard tubes
This stuff is not Slime. Almost every other tube sealant out there clogs valves, dries out, doesn't work well, and generally makes a mess. TruGoo lasts for years, cleans up easily, and does not clog the valve. It will seal small punctures like the goat heads and stickers we have here in the central Midwest. We here at the shop have been using it for 7 years and found it very effective when used properly.
At $5 per tube it is cheap additional insurance.
If you do get a sticker or thorn remember that the best solution is to spin the wheels or ride the bike. If you go out to your garage and discover a complete flat tire, try airing up and spinning the tire. If air is leaking quickly, then there is possibly a problem the sealant cannot seal. This is very rare.