How to Tell If You Have Tubeless Tires on Your Mountain Bike
To tell if you have tubeless tires on your mountain bike, look for the words “tubeless” or “TL” on the sidewall of the tire. Additionally, tubeless tires will not have an inner tube, so you can remove the valve stem and see directly into the tire. If you have trouble determining if your tires are tubeless, consult with a bike mechanic or ask the manufacturer for clarification.