New tire goes flat

TVB · Post by **TVB** » Sat Mar 30, 2013 3:41 am

So.

A few weeks ago I took the scooter into the shop for a variety of repairs and maintenance, so that all would be right with it to start the riding season. The rear tire was getting thin, so they replaced it. Last weekend I hiked back out to the shop to pick it up. And for nearly a week, all was right.

Then tonight, after stopping at the store for assorted groceries, the rear tire gave out on me. I was going pretty slow, so I didn't lose control; it was just a matter of pulling over. And confirming that yup: no air pressure. The tire was just hanging on the wheel, offering no resistance when I squeezed it. I hiked the rest of the way home, then drove back with the chain I use on my front porch, to lock it up to something. (It's in that kind of neighborhood.) I'll deal with it in the morning.

I don't know for sure whether it's a tubed or tubeless tire. That's not something I have any kind of informed opinion about, and I didn't think to confirm at the time which it was, and I couldn't tell tonight in the dark. I couldn't feel a tube, but it was my understanding that a tubeless tire wouldn't deflate all of a sudden like this unless it was badly underinflated or badly punctured. It's conceivable that I ran over something (again: couldn't tell in the dark) but my first thought is that this shouldn't be happening 6.5 days after picking it up with a brand new tire. Any thoughts?

tortoise · Post by **tortoise** » Sat Mar 30, 2013 3:50 am

charlie55 · Post by **charlie55** » Sat Mar 30, 2013 1:55 pm

Dooglas' post in this thread tells how to tell the difference:

topic9917.html

If it is indeed tubeless, it could be something as simple as a faulty seal on the valve stem, or even the internal valve mechanism not being screwed in tight enough.

TVB · Post by **TVB** » Sat Mar 30, 2013 9:06 pm

With the benefit of being able to see, I was able to determine that it is in fact tubeless.

I called the shop (Woodland Travel Center of Grand Rapids) when they opened this morning, and without me having to argue my case, they just took care of it. They picked up Flash and me where I'd locked him up for the night, and trailered us to the shop. The mechanic re-inflated the tire and saw it was leaking kinda bad at a couple spots on the rim. So it'd probably had a bad seal all week, and the extra weight of groceries put enough pressure on it to lose air more quickly, and once it got to the critical threshold, the seal collapsed and ... flop, flop, flop.

So he checked the tire further for any damage, then cleaned up the rim extra smooth, and remounted the tire with bead sealant. No charge for the pickup and repair, and apologies for the inconvenience. Plus he took the initiative to lube up my sticking center stand and ask if there was anything else he could do for it. All things considered, I'm satisfied.

mukaiboston · Post by **mukaiboston** » Sun Mar 31, 2013 12:20 am

Just had a similar incident the other day.

I just got new tires, but my rear tire valve had dirt in it and air was slowing leaking out. Getting a flat on a scooter is scary.

theflash784 · Post by **theflash784** » Sun Mar 31, 2013 12:34 am

Glad the dealer took care of you and everything worked out with the new tire.

TVB · Post by **TVB** » Sun Mar 31, 2013 1:31 am

mukaiboston wrote:Getting a flat on a scooter is scary.

A bit scary, but I was surprised afterward that it hadn't been as bad as I'd assumed a sudden flat would be. My slow speed (probably 25-30mph) was part of it, I'm sure. And I guess the dozens of sudden flats I've had on my bicycles over the years conditioned me for it.

Post by **ericalm** » Mon Apr 01, 2013 6:46 pm

With a puncture in a tubeless tire, what will often happen is that it loses air fairly slowly and will start to feel loose/slippery/like riding on a blob of gel.

I had a very large wood screw puncture a tubeless tire in two places (went in diagonally and pieced the sidewall) and the air still came out gradually!

"Catastrophic" sudden loss of pressure isn't impossible, though. You usually wan't have an explosive blowout, just lose all pressure at once. A common cause is a valve stem failure. But, as reported above, there can be other causes.

Maximus53 · Post by **Maximus53** » Mon Apr 01, 2013 8:11 pm

TVB wrote: So he checked the tire further for any damage, then cleaned up the rim extra smooth, and remounted the tire with bead sealant.

Is bead sealant a common thing to use with tubeless tires? I bought a set of SIP tubless rims for my Stella and had K61s mounted and both tires had slow leaks without fail. The mechanic mentioned that when he worked at a car tire shop they commonly used it, but had never heard of using it on a motorcycle tire. I would love to go back to my tubless rims.

TVB · Post by **TVB** » Mon Apr 01, 2013 10:40 pm

The mechanic said he almost never uses sealant, and wasn't even sure they had any (he was planning to improvise something before he found a can of it). He used it for mine mostly because he didn't want to see me again next week.

TVB · Post by **TVB** » Mon Apr 01, 2013 10:46 pm

ericalm wrote:With a puncture in a tubeless tire, what will often happen is that it loses air fairly slowly and will start to feel loose/slippery/like riding on a blob of gel.

I didn't notice this happening beforehand, but after a couple months with almost no riding, grit-strewn post-winter roads, and a brand new rear tire, I was still getting accustomed to the feel of the bike... so I didn't have a good reference for comparison.