Yesterday, nearly a week after finishing the wheel build and mounting the tires, I set out to inflate the tires. For tubeless this means removing the valve core and filling the tire with a burst of air, pushing the tire bead fully up onto the lands at the edge of the rim and creating a seal.

The tires had been quite hard to work over the rims, and I thought the tight fit would make for an easy job of sealing. I started with the front tire. I charged the pump up to 120psi, held the pump head to the valve and let ‘er rip. A lot of hissing, a bulging tire under my hand and then … pop! pop! pop! Seated on the first try!

Of course I have to let all the air out of the tire when I remove the pump head, and it’s with some regret I released it and heard all the air whooshing out again. But it had worked! First try! I took my time pouring sealant in through the valve and replacing the core, before pumping the tire up again to its rated limit of 60psi. And with that, and no bubbling or other signs of leaking, I swirled the sealant around the tire and cleaned up the little spills that had occurred in the process.

All that boded well for the rear tire, or so I thought. Setting the front wheel aside, I removed the valve core from the rear wheel and charged up the pump to 120psi. Once again, with my hand holding the pump head in place, I let ‘er rip. The tire bulged satisfyingly as the air whooshed in from the pump, and then … the air kept whooshing. No pop. No seal.

I know from experience that sometimes the friction between the tire and rim can be an issue, so I mixed up some soapy water and splashed that around the area where tire and rim meet. Charged up the pump for another go and … same. Same same. I tried once more and gave it up for the day. It was 35C, I was sweating profusely, and I wanted to take some time to think it over.

Which brings us to today

I got an earlier start today, about 10 a.m., when it was a bit cooler not quite as hot as it had been at 2 p.m. yesterday. First I ran a tire lever around the entire rim, under the tire bead, making sure that it wasn’t stuck to the rim anywhere. After that I made up some soapy water and liberally applied it all around the tire seat on the rim.

And I gave it my best go. Another two or three times, all with identical results. I could see just a bit of bubbling where the tire wasn’t moving onto the seat. Before the last go I even used the tire levers to remove the tire from the rim on one side, all the way around, and then worked it back in place. It made no difference.

Cooler heads

There’s a tactic I’ve used several times in the past with success when a tire wasn’t seating, and as I relaxed under the A/C in the den I realized it was time: set up the tire with a tube, run it that way for a couple of weeks or more, and then switch to tubeless. These tires were very difficult to mount on the rim, but I’d already had one side off so what’s the difference?

I didn’t have too much trouble unseating one side and removing the valve stem, then inserting the tube. But then reseating the tire was quite the challenge! I ended up using the tire levers and really fighting with it. I could see flakes of something falling out as I was working, but I was more concerned with my tough plastic tire levers behaving like tootsie rolls as they fought against the tight tire bead. At last I managed to wedge the tire back in place — only to discover I’d mangled the rim decal in the process.

Deep breaths. OK. Anyway the important point is I can inflate this tire now and move on with the project, right? I attached the pump and worked it up to 20psi, then 30 and then … pssshhh! The tube was leaking. I’d checked it before I began working and so I can only assume I pinched it in all the above forcing of the tire back onto the rim.

Next step?

At that point I’d been working at it for an hour, and I was dripping sweat. It was definitely time for a break, a regrouping to consider my options. I have at least two more tubes the same size on hand that I can work with. At the moment trying them seems the best option — short of trying a different tire brand or even a different rim.

As an interesting note, these tires and the ones I recently installed on Hornsby have been the most difficult to mount of any I’ve encountered. Although different in appearance and tread, they’re all 650B x 42C. And — although it’s not immediately apparent — they’re the same maker. (Hornsby’s tires are Fairweather brand, but it’s made by Panaracer.) The Panaracer tires for Kuroko are meant for tubeless use, while Hornsby’s Fairweathers are not.

I’ve ridden Panaracers of the same size in the past (the ones I’ve just removed from Kuroko are an example) and not had this much of a fight just getting them on the rim. But at this point I can’t say if it’s Panaracer or the rim makers at fault — my previous experience was with the Hunt rims and I’m not using them now.

I’ve alread shared pictures of these wheels and gotten positive remarks about their appearance. The shredded logo hurts a bit. And it’s on the drive side, which is the side from which I usually take photos. But I’m going to be philosophical and say that’s what all the decals are going to look like after six months of riding — if I can only get the tire inflated!