A flat tire can ruin your day if you're not prepared. Fortunately, multiple options exist to plug that hole and let you ride home, or beyond. Some are easy to use, others not so much, and prices are all over the place. Which one is the best? Wrapped within a mini-mocumentary video, FortNine finds out by putting each one to a maximum pressure test. We'll cut to the chase and give you the straight scoop on the results.
Rope Plug
This is the plug most of us already know about, since it's been around for probably as long as the tubeless tire has existed. Goop up the plug, use the tool to shove it into the hole, remove the tool, and you're good. (Some say to cut off the excess, but if you don't have a knife it wears off pretty quickly.) At $19.95 on Revzilla it's the cheapest for roadside repair. It's pretty easy to use, though some of the other options are easier.
The rope plug held up to 125 newtons (28 pounds) of pressure before letting go. That may not sound like much, but keep in mind that all that pressure is concentrated on a tiny surface area. It's like putting that much pressure on a screwdriver against your tire. Given the size of a contact patch, in the real world only riding over a sharp rock directly on top of the patch would apply this much force to it. After springing a leak, the rope plug resealed itself when the gauge was removed, preventing further leakage. None of the other plugs did this.
Mushroom Plug
The mushroom plug kit is the most expensive option, selling for $53.95 on Revzilla. It's also the largest and most complicated to use. It requires you to bore the hole in your tire larger to match the size of the rubber plug, which is in the shape of a mushroom. Use the special tools to insert the plug into your tire, use some pliers (not included) to pull it tight against the inside of the tire, then cut off the extra. Then use either the included CO2 canisters or a tire pump to reinflate the tire, because this method will let all of the remaining air out of your tire as you bore the hole big enough for the plug.
After all that trouble, expense, and hassle of carrying a large repair kit around with you, the mushroom plug only held up to 80 newtons (18 pounds) in the pressure test, the least of any of these patches. While I wouldn't say this plug could kill you the way the video title does, I would say that it's not worth paying more than twice as much as the least expensive plug for one that's less convenient to use and doesn't work as well.
Spear Plug
Also known as the "Dynaplug," this little gadget sells for $29.99 on Revzilla. Unlike the mushroom plug, this kit is tiny and super easy to use. Simply load a plug into the end of the tool, stab it into the hole, pull out the tool, and you're done. These plugs aren't sticky like the rope plug, though, plus the kit is more expensive.
Under pressure, the spear plug gave out at 122.5 newtons (27.5 pounds), almost identical to the rope plug. Unlike the rope plug, though, it did not fully reseal afterward, leaving a slow leak in the tire. You're not trying to set any tire repair speed records here, and the rope plug is still pretty quick and easy to use.
Internal Plug
Professionals consider an internal plug to be the only permanent tire repair. The other options are supposed to be only temporary. At $15.99 on Amazon for a pack of 10, this is technically the least expensive solution. The only problem with this type of plug is that you have to dismount the tire to apply it, which you won't be doing on the side of the road. In my mind, if you're already dismounting the tire anyway, you might as well just pop a new one on and not worry about patching it.
The reason why the pros consider this the only permanent repair became clear in the pressure test, where it withstood a whopping 460 newtons (103 pounds) of force, which made a new puncture in the tire. The patch itself still didn't fail. The likely reason why this patch works so much better is that it has much more surface area to bond with the tire than any patch applied from the outside can provide. However, not being usable for a roadside repair renders it less useful for our purposes.
Fix It Yourself:
For once, it seems the best solution for a roadside repair is also the cheapest, the tried and true rope plug. It's the stickiest, strongest after the internal plug, and also the most versatile. In a pinch, you can even cram more than one rope plug into a particularly large hole if you have to.
We should also mention that this only applies to tubeless tires. If your tire has a tube, like many cruisers and dual-sports (generally, any wheel with spokes, though there are exceptions), these plugs won't work. In this case, it's the tube that holds the air, not the tire itself. No matter what, you'll have to pull the tire off the rim to fix it. The good news is that if it's only a small puncture, you can simply replace the tube for cheap and reuse the tire. You can also patch the tube, but why take the chance of a patch springing a leak?
Sources: FortNine on YouTube, Revzilla, Amazon