Archive for August 8th, 2010
We’re getting set up for a bicycle vacation and I did a quick tire inspection… good thing, too, considering the gashes I found in the rear tire on Mary’s Tour Easy.
I put Schwalbe Marathon 700x35C tires on the back of our ‘bents, for well and good reason: Marathons have plenty of rubber and include a Kevlar puncture-resistant layer. In this case, that was just barely enough!
Here’s a cross-section through the tire; the Kevlar layer is yellow, with the tire carcass fibers inward of that.
The greenish-yellow tint in the left-hand gash (in the top picture) is the Slime tire liner (they prefer “tube protector”) showing through. Here’s what the liner looked like after we pulled the tire off; the liner shows some damage, but it’s just surface scuffing.
Quite by coincidence, the gashes straddled the overlapped end of the liner. The end of the liner is on the tube side; I haven’t trimmed or tapered the end of this one.
Here’s what the inside of the tire looked like; the Kevlar fought the gashes to a standstill and left the carcass mostly intact. The painted and illustrated fingernails belong to my shop assistant.
Here’s a cross-section through the Kevlar layer. I don’t know what Mary ran over, but it was most likely a sizable chunk of the broken glass that litters the roads around here. I doubt anybody gets prosecuted for littering, but as far as I’m concerned, a fitting punishment would be collecting the glass from a few miles of roadway: crawling on hands and knees, picking up fragments with their lips.
I put a new tube in a new Marathon (for obvious reasons, I have a supply of both on the shelf at all times), we positioned the liner, pumped it up, and it’s all good.