Until I began running tubeless tires, I didn’t understand what the big deal was. I didn’t flat all the often and it didn’t seem like the ride quality of the tires I rode was in some way inferior.
Then I rode some wheels set up with tubeless tires. Here’s what I can report of the experience: I didn’t immediately feel a difference in the bike’s ride quality. The combination of full suspension and a 2.1-inch tire didn’t communicate anything significantly different from what I typically perceived. However, I did immediately notice an improvement in traction. after running the tires first with tubes then setting them up tubeless at exactly the same pressure, they offered better grip. And because you can run tubeless tires at lower pressures without risk of suffering a pinch flat, once I dropped the tire pressure by 5 psi, the trail-holding power of the tires fundamentally changed cornering.
I’d sooner give up my dropper post than go back to riding a mountain bike with tubes in its wheels.
With gravel riding, I’ve seen as big an improvement in comfort as traction and I’ve been able to discern no increase in rolling resistance. As someone who has ridden a few thousand miles on a touring bike running 35mm tires with tubes, the rolling resistance from running them at 60 psi convinced me that I’d never run a tire of that width at 40 psi and manage to pedal better than 20 mph. How times change.
So that’s the experience of riding them. What holds many riders back from making the switch to tubeless is setup and it’s not nearly as difficult as it sounds.
The shot above is of the once ubiquitous Mavic MA40. It was a reliable rim, but a great many tires didn’t go on the rim easily. Vittoria open tubulars required tire levers just for mounting. Why? The inner diameter of the rim was, when considered against some of its competition, rather large. The larger a rim’s inner diameter, the tougher it is to mount a tire.
Given how snug a tubeless tire must fit, it’s easy to conclude that you’ll need a crowbar to mount the rubber. That’s not the case.
You’ll notice that in the shot above there’s a deep central channel in which the valve sits. That central channel is the key to running tubeless tires. You’ll also notice that no such channel exists in the Mavic rim.
When mounting a tubeless tire, its important to make sure as much of the bead sits in that channel as possible before trying to push the last of the bead over the rim. That can be the difference between slipping the tire on with your fingers and using a tire lever to mount the rubber. This goes for both sides of the bead. Be patient and make sure the bead follows that channel faithfully.
I’ve encountered tires with a large enough inner diameter compared the the outer diameter of the rim that one side of the bead would slip off even as I was pushing the other side on. And any time I run into a rim with a reduced channel, I end up having trouble no matter what the tire is.
In removing a tire, it’s just as important to push both sides of the bead into the channel—all the way around—before attempting to remove the tire. This is the biggest single mistake I see people make. I’ve watched guys break tire levers when they failed to take this step. With mountain bike wheels and tires, as long as I take my time to push all of the bead into the gutter I am able to remove the tire without the need for a tire lever.
With wheels and tires meant for multi-surface road riding, all the same rules still apply, but I will say I run into challenging fits with greater frequency. That said, as long as the rim is properly taped, I haven’t had to use a tire lever to get a tire 35mm wide or larger on or off a rim. Which brings me to the subject of taping.
When taping up a wheel for the first time, you’ve got to respect that trough. Make sure the tape follows every contour of the rim as faithfully as possible. I was standing in a friend’s shop on an occasion when a customer came in with a wheel set he was unable to mount tires on. It turns out he hadn’t pressed the tape into that recess and the extra four or five millimeters of fit made it impossible for him to get the tire on. Even after re-taping it was a reasonably tight fit.
Regarding the subject of tape, I always tape my rims with two layers. A second layer doesn’t weigh much and it can make a difference in how quickly the tires hold air. I don’t want to put six ounces of sealant in the tires. I go slowly as I wrap and I’m careful to make sure not to get any folds in the tape or allow the tape to run up the side of the rim where it can interfere with the seal between the bead and hook.
Finally, I know some of you are wondering about the pure road application of tubeless, especially with tires of 23 or 25mm width. I’m not running any wheelsets this way. I’ve twice set up tires and wheels only to have the tire blow off the rim around 60 psi. It sounds like a gun shot and the resulting spray of sealant can take a half hour to clean up. I recommend getting your clothes in the washer immediately. On top of that, none of the road rims I’ve used so far have had a deep enough trough that I’ve been able to mount the tires without at least one, if not two, tire levers. When I’ve ridden road wheelsets set up by someone else, I haven’t felt the heavier tire and lower pressure resulted in a ride superior to an open tubular with a light tube.
I’m sold on tubeless for mountain bikes and multi-surface road bikes; that one change in technology could improve rolling resistance and traction while also eliminating pinch flats almost seems too good to be true. Almost. It is true.