While doing a mountain descent ( Glendora Mt. in S. CA ), steering on a curve went really scary. Our front tire was really soft. We were able to stop fine and there was no obvious cause for what seemed like a slow leak ( tire still had a little air ; maybe 20-30 psi ). At home, I pumped up the tube, and still no leak, although there was a small bubble on a patch I had applied quite some time ago. So, I'm thinking the patch melted enough to leak. It was not a glueless patch. The wheel was pretty warm, when I stopped, but not too hot to hold. Anyone else have problems with patches melting? Maybe my first time, in almost 40 years on a tandem with this problem. It was scary enough, that I might not patch tubes on the tandem anymore.