I had a weird thing happen over the weekend. I was climbing up Highway 39 out here in LA. It was blazing hot and the road temps had to be beyond 140 degrees or so. I'm running a set of newish FMB Roubaix 25c tires. During the climb, my rear just started losing air fast. I pulled off the road and inspected my rear tire and not a single puncture. Used a C02 and filled up the tire and continued on the climb. Maybe another 30 minutes I'm losing air again. WTF? I put in 1/2 bottle of stans sealant and the sealant was almost coming through the tire, like the tread was transparent, fricken weird right?
I make it up to the top of Crystal Lake and now my tire is holding air. Before the descent I used a buddies frame pump to put as much air as possible to make it down the 15mi descent back into Glendora. When I get to the bottom, everything seems fine. I get home and pump the tire up to 110psi just to fill it up and monitor the air loss. The tire has sat for about 24hrs and it' still pretty hard, maybe down to 100psi.
When I pulled over on the climb the second time, I noticed my tire was ridiculously hot, like even hard to touch with bare hand for longer than a few seconds. My question is, can the latex tube inside a tubular tire get so hot that it loses air in that manner? My guess is the road temps were so hot that the latex couldn't hold air. Is that a good guess at what happened? Are FMB tires and other latex inner tube tubulars sensitive to hot road temps?
I was all bummed that my Roubaix tire was trashed and losing air, but once I got home and under cooler temps the tire holds air like normal.