I pondered the merits of tubeless wheels the other day for quite some time as I pushed my flatted bike more than two miles to the parking lot. Bottom line, I would have ended up pushing even if I had a tube due to the circumstances, but we’ll get to that.
First, why do people run tubeless? 1) It’s the newest, hottest thing. There’s no argument against that line of reasoning. It’s why I’m running tubeless….so I can talk about it as the newest hottest thing. It’s lighter than running with tubes. Subtract two tubes, then add back in the sealant and you have a savings of maybe 260 grams (a little over half a lb.) depending on the tubes and how much sealant. However, the most compelling reason is that you can run much lower air pressure (20 – 35 lbs.) and not risk pinch flats. The lower air pressure provides more grip, especially in cornering situations.
Good stuff. But what happens when you flat with tubeless tires? There are a number of ways to flat no matter what you’re riding and sometimes what you have in your tool bag will determine whether you ride or walk off the trail (or even get on the trail in the first place). Flat Scenario 1: Tubeless tires will lose air if you don’t keep your sealant refreshed and distributed on the inside of the tires. The sealant fills in air holes, so if it’s not coating the inside of the tire, air seeps out. If you ride infrequently you will probably have to check your sealant, and/or air up every time you ride. Flat Scenario 2: Running low air pressure sometimes results in a ‘burp’ where the tire compresses too much and pulls away from the rim letting air escape – usually if you hit a rock or root at a funny angle. Generally, all you need to do for this is refill with air using a CO2 cartridge and head (hand pumps generally don’t provide enough volume when you break the rim seal) Flat Scenario 3: When you run over a thorn or nail, the sealant inside your tire should fill the hole. If it doesn’t, you either don’t have sufficient sealant, or the hole is too big to fill. Carry a small bottle of sealant and CO2 cartridges to make the repair. If the hole is too big, you might need a tube to remedy the situation.
The other day I fell into scenario 3. A rock ripped a lug off my tread creating a hole too big to fill with sealant. Even if I had a tube, which I didn’t, I would have had to insert a boot to keep the tube from leaking out the hole. I didn’t have a boot, or anything that would have worked such as a dollar bill, or mylar Gu wrapper, so I did what we all have to do from time to time….walk.
But I’m going to stick with tubeless, at least for now. I put a reminder on my calendar to check sealant every 2 months. And on my long rides, far away from civilization, I will carry a tube and a boot because I really prefer biking to walking any day.