Tubeless tires vs. the mechanically inept

Calling someone mechanically inept is not an insult. It’s a diagnosis. The description covers a range of conditions that all lead to dependence on someone else to take care of your machinery.

I am semi-inept at auto mechanics. In the 1970s I could do a fair amount of routine maintenance on my Triumph Spitfire, because it was about the easiest car you could ever hope to work on. Everything was accessible, and four strong people could pick it up by hand and put it on jack stands. Well, maybe not quite. I never had friends that burly. I did what I had to, as a low-budget sports car owner, but I never looked forward to working on it.

As cars evolved, everything became less simple. I hung on doing oil changes for a while, but then I got a car where it was hard even to get a wrench on the friggin’ drain plug unless you were working from a pit or under a lift. Screw it. As for any diagnostics, I take my best shot and then find out from my mechanic how wrong I was. There are always factors that I didn’t consider, things I didn’t know. And it's all easier when you have a shop set up for the purpose.

My car mechanic engages in continuing education, but it’s independent study, the same way we research bike stuff here at the shop. He disparages modern disposable cars the way I disparage modern disposable bikes. But we both have to operate in the current universe of gratuitous technical complexity.

A customer dropped off her bike today to have tubes put in her tires. She’d been told by her hard core mechanic at the shop she patronizes in the city where she works, that tubeless tires were far superior to having tubes, because now she could run fashionably low pressure on her gravel bike without fear of flatting. Low pressure is faster, he told her. I didn’t gather that there were a whole lot of qualifiers with that. Everything is relative.

The front tire had been frustrating her because it goes dead flat overnight. She was tired of dinking with it. When I popped one bead off, I discovered that there was barely any sealant in the tire. It could have lost it a bit at a time with each complete deflation. It could have had too little from the beginning. I didn’t see obvious residue on the tire casing or the rim, but she’s been riding the bike regularly, pumping up the offending tire before every ride. Residue could get rubbed or washed away in the course of events. Because I don’t have much control over what happens to the bike when it leaves here, and I don’t share the current enthusiasm for tubeless, I hesitate to tell her that we can clean it up, juice it up, and she’ll be fine. She might not be. She specifically said she didn't want to mess with it anymore, so I'm not about to suggest that she give it another shot. If she wants to go for it later we can do it. The rims are already taped. She already owns the stems. I would suggest starting with fresh tire casings. And I make no promises for the technology. I have no vested interest in it working or not.

The only time I’ve seen sealant work has been installing brand new tires on relatively new rims. Other than that, the stuff baffles me. It’s supposed to stop leaks from punctures up to the diameter of a pencil, but how many days are you supposed to sit there by the side of the road or trail? As far as I can tell, the shit takes forever to dry, and is seriously challenged by more than a couple of pinholes.

Highly respected brand Orange Seal recommends replacing their basic formula sealant every 30 to 45 days. How many of you are doing that? Are any of the mechanically disinterested going to do that? The longer the shelf life of the sealant, the slower it actually seals anything. The shorter the drying time, the more frequently it needs to be replaced.

You might think, “I’ll support my LBS and just hire them to replace my sealant at the requisite intervals.” Congratulations. You’ve just tied your bike up in the repair queue for however long their backlog is at the moment. Someone can just add sealant, whether it’s the rider or an overloaded technician, but eventually you have to clear out the blob and start over. Just buy new tires.

You're also not supposed to mix brands of sealant. If you can't get your regular stuff, you're supposed to flush out all of the previous fluid, let the inside of the casing dry, remount the tire and fill it with whatever you have enough of. A repair shop needs to have bottles of every brand ready to match whatever is in a customer's bike already.

Today's tubeless tire challenge overlapped with a multi-day tubeless installation on another customer's 29-er wheels. His tires were "tubeless ready" when they were new, but a few months of riding at low pressure had worked the sidewalls quite a bit. It wasn't obvious until we put in sealant and pumped them up. Sealant began weeping through the sidewalls. The front tire held up okay overnight, but the rear went pretty flat. I spent the next day topping up the pressure and flipping the wheels every few minutes to keep the sealant distributed over the sidewalls. The front tire kept getting steadily better. The rear improved much more gradually. I marveled at how ineffective the sealant was at closing the myriad tiny pores along the thread lines of the sidewalls. They're fully coated with black rubber. The thread  structure wasn't prominent until the lines of bubbles brought it out.

We're ordering him new tires. Meanwhile, he'll go for short rides on what he's got. If you're going to ride tubeless, plan to replace casings frequently, even if you don't think you are riding a lot. It doesn't take much to break down the airtightness of a tire casing. It may be structurally sound with decent tread left and still not seal well without a tube. Mo' money. Fork it out.

Another thing to remember is that sealant will clog valve cores. The mechanically inattentive rider will run into difficulties inflating the tire as a result.

In the off season -- if you know that it's the off season -- you're advised to take the tires off, clean out the sealant, rinse and dry the casings and leave them off until you're ready to take up riding again. No grab-and-go rides on a mild winter day for you! Tell me again how it's great to get away from inner tubes? If you don't do this you could end up with a lump of congealed sealant in one part of the tire. You're also wasting the life span of it with the bike just hanging on a hook.

There are lengthy forum threads devoted to proper use and care of tubeless tire setups. More entertaining reading for those who care. But if you remember when bikes were something that you didn't have to obsess about I suggest that you forego as much of the tweaky technical crap as possible.