Thursday, July 21, 2011

bulbous beginnings

It began not five minutes into the ride. A thump, thump, thump, evenly spaced like the sound and feel of a thump when riding over sidewalk cracks or highway seams. Thump, thump. I veered to a smoother section of the gravel road. Thump, thump. I looked down at my front tire and could see a bump making its way around again and again. I yelled for Jon and stopped the bike.

What I saw resembled a small turtle clinging to the tire*. I immediately found the valve stem and started releasing air from the tire. All I could think was that this tire was about to explode and our 30-mile bike ride was about to become a much shorter hike.

I knew the tire had a hole in it. It's tubeless and since reinstalling it on the bike this spring I've needed to put more air in it before each ride. I've been meaning to patch the hole ever since Jon found it one day when he was kind enough to clean my bike. But I just haven't taken the time: it's easier to pump it up every few days and hope it lasts.

Now I was worried that my deferred maintenance was going to cost me a ride I've been meaning to do: A loop that had us staring at the Primrose campground on Kenai Lake, biking the Seward Highway south to the Lost Lake Trailhead, then riding the 15 mile backcountry trail back to our starting point. I've always biked the trail in the other direction, sometimes completing the loop with a ride up the highway after finishing the trail. I wanted to see why people like riding the trail from the Lost Lake Trailhead to Primrose. Call it research.

Jon rode up to me and saw the turtle. "Let air out," he said. Already did, I told him as I squeezed my now-flat tire. It wasn't in the same location as my puncture, he assured me. Best he could surmise was that there was a hole in the inner lining of the tire that allowed air in and quickly caused the tire layers to separate, resulting in the goiter-like bulge. He told me he had never seen this happen before. Oh, I'm sure if we looked it up, we could find instances where this has happened, but it was a first for us.**

To fix the bulge that remained even after I deflated the tire, Jon pulled the tire from the rim and cut a hole in the inner lining to release the air, then we installed an old-fashioned inner tube. We had nearly 13 highway miles to cover, plus some more gravel road before hitting the trail. My paranoid self thought she saw a little wobble in the tire as we rode the highway. Though it was a beautiful summer day and a great ride, I kept dreading a pinch flat on one of the countless rock waterbars along the trail. By the time we reached the car, about 6 hours after we began, the only thing I wished I had more than an extra tube was some sunblock. I'll chalk it up to experience and bring two spares on my next long ride. I'll also remember the sunblock next time.

*I'm sorry I don't have a photo of the crazy bulge on my tire. My camera has been in for repairs (yes, sometimes you can get cameras repaired) & we don't have a backup. Rest assured, it has been sent back from the repair center and is in transit. I'll be glad to have it back.

**I did a little more looking and found this interesting thread. "Tire hernia" is a good description. My tire is a Maxxis, but I wasn't using Stan's or any other sealant in the tire.


don said...

I'm a road bike guy and not really a mountain bike guy, and I do have a fondness for tubular road tires, but I'm not sure I see the advantage to tubeless mountain bike tires. I'm sure there must be one.. I've used a dollar bill to keep a tube from coming out of a clincher sidewall in the past.

bikegirl said...

Don - tubeless on a mtn bike allows you to run the pressure lower w/out the risk of a pinch flat. They also provide a different ride feel I could describe as being a little "floaty," or like having a little pillow to ride on. I don't think it makes sense until you ride on them. I think lots of people in the thorny areas use them, along w/some slime.

As for tubulars, they seems like lots of work if you get a flat, but I know they've been regaining popularity in the last few years. And, yes, dollar bill or energy bar wrapper w/duct tape works. Because my puncture didn't go all the way through we weren't worried about the tube pushing through.