Senior Member
Join Date: Jun 2011
Location: Sunnyvale, California
Posts: 1,180
Bikes: Bridgestone RB-1, 600, T700, MB-6 w/ Dirt Drops, MB-Zip, Bianchi Limited, Nashbar Hounder
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Could be coating on the tube to prevent the rubber from reacting too fast to ozone and other stuff that might make it crack during storage. Or it could be one of those pesky seams. If the hole is right there, it allows for a small pocket to remain and air bleeds slowly into that pocket and eventually lifts the patch off. You might scuff that area flat with emory cloth more, and you might use some small amount of acetone to buff the spot before trying to use cement. Thinner patch will also stretch more easily to hold just long enough to prevent leaks until pressure pushes the patch tight against the tube.
But at some point, I usually scratch my head, toss out the old tube and get a new one.