Thorn protection is essential for bikepackers and bike commuters. Changing a flat tire might be fun the first few times you do it, but constant flats will slow you down, threaten your trip, and drive you mad. Fortunately, you don’t have to have a tubeless set-up to get stellar protection against thorns. While tubeless has become the gold-standard for mountain bikes, not all of us deal in gold.
I recently tested this setup on the Monumental Loop, a 250 mile bikepacking loop, notorious for thorns. Like many things, finding budget-friendly, yet time-tested advice simply involves asking the question: “What did mountain bikers do 10 years ago?” Chances are what worked then, will still work now.
Thorn Defense Level 1 — Tire Liner
The first layer of defense in the system is a tire liner. Tire liners fit between your tire and precious tube. They stop the majority of thorns from puncturing your tube. Tire liners are made of foam and nylon. Popular brands include Mr. Tuffy and RhinoDillos. Both products are easy to install. Simply, remove your tire from the rim, add the tire protector and return your tube to the rim. The inflated tube will hold the liner in place. You can also experiment with using Gorilla Tape for a lighter weight alternative.
Foam tire liners
A new type of tire liner, made of heavy duty foam has entered the market. While some of these liners are geared towards downhill mountain bikers, the technology claims to protect against thorns as well. Tannus, a manufacturer of foam liners, claims that in addition to thorn protection, you can reap other benefits, like running lower tire pressure without upgrading your wheels to tubeless.
After ordering a pair, I ultimately decided that Tannus Tire Armor was more than I needed. I still haven’t tested the tire liners, so I can’t speak to the company’s other performance claims, but there are a number of promising reviews.
Note: these liners are heavier and more expensive than other options.
Thorn Defense Level 2 — Tire Sealant
Using both methods above will give your reliable thorn protection for bike packing or bike commuting. However, for longer trips or peace of mind, it’s best to still carry a spare tube and patch kit in your repair kit. Most small punctures can easily be patched.
In a tubeless system, liquid tire sealant that lives inside the tire works to stop leaks. Anytime a puncture happens, the sealant races to fill the hole. Sealant is made of tiny bits of nylon that plug the leak. Fortunately, you don’t have to ride tubeless to reap the benefits of tire sealant.
A variety of tire sealant products exist. The most popular include StansNoTubes, Orange Sealant, FlatAttack, and Slime. Some of these are marketed towards tubeless riders. Others claim to be better for putting directly in tubes. Products geared towards tubeless systems tend to be lighter. Fortunately, they are all relatively similar and serve the same purpose of fixing flats.
To use sealant, you’ll first need to remove the valve core from the tube tube. All schrader valves have a removable valve core, but require a small metal tool. Some Presta valve cores can also be removed. This procedure is very simple. Depending on the type of valve you have, it can be accomplished with a wrench, needle nose pliers or a small valve core removal tool (ask your bike mechanic if they have extras).
After adding sealant and filling your tube with air you’re ready to ride. Sealant will fill punctures that make it through the first line of defense.
Thorn Defense Level 3 — Patch Kit and Extra Tubes
At the end of the day, this system works to minimize flats. It still makes sense to carry a spare tube and patch kit in your bike repair kit. On my most recent bikepacking trip, I found myself pulling out endless goat-heads without springing a leak. Far from the trailhead, it’s nice to have backups. By combining different types of flat protection, you can achieve extremely reliable protection against thorns and stop flat tires when bikepacking or bike commuting.