Flats happen.
And we’re all prepared for a flat with a spare tube, patch kit, CO2 cartridges or pump. Right?
But have you ever seen a tire split or get cut enough so that it doesn’t hold the tube? At 100 psi, a tire will push its way out of even a small cut in the tire and will burst. And if you’ve already used your spare tube (because your tire is cut and you just had a blowout) you’ll quickly blow the second one while inflating it.
I know. Because I’ve done it.
Here’s an important tip: when you get a flat, try your best to determine the cause. If you can, find the hole in the tube, and match it up with the tire. At least inspect the tire very well for something sharp (glass, wire, metal) poking through the tire. Slide your hand through the entire inside of the tire to feel for something sharp. Something caused the flat, and if you can’t figure it out, be very suspicious.
Types of Flats
There are many different types of flats:
- Puncture: glass shard or metal wire
- Pinch-flat: hitting a pot hole or rock. Sometimes called a snake-bite because the tube has two holes close together.
- Tire damage: split tire or cut sidewall
- Blowout from heat: Too much braking on a carbon rim can melt your tube or even the tire. (Or worse, warp your rim – ouch!)
- Damaged valve: most likely caused when inflating, not riding.
Tire damage is the worst kind to get because we usually don’t carry spare tires around with us as they’re pretty bulky. Though you can get a folding tire into your pocket for longer rides.
How to temporarily patch up a cut or split tire
If you do get a split in your tire, there’s an easy fix that should get you home. Just take a dollar bill, fold it up, and insert it into the tire to cover up the cut. Get it in place between the tube and the tire and inflate.
If you don’t have a bill, a Gu wrapper, or some piece of strong flexible plastic will do the trick.
I always carry a dollar bill around in my saddle bag for this purpose.
This technique is called a “boot”. It is obviously not a permanent fix, but it’ll more than get you home or even to the end of your century ride.



Many things can go wrong with a bike when you’re out on the road, and most of them can be handled with just a little preparation, ingenuity, and out-of-the-box thinking.
Because there’s nothing like a two-hour round trip for your spouse to sour him or her to your favorite pastime.
We’ll cover more of these MacGuyver techniques in future posts.
Nice post, Scott. Tips like these are how I first discovered Bike Noob years ago.
Thank you Jeff!
For a better boot, I like to carry a 3″ piece of a lightweight road tire with the beads cut off.
Also, the rubber logo stitched on some Camelbaks makes a nice boot.
the Camelback logo! Now that’s MacGuyver-ing.