Never have had a problem patching tubes, just make sure the surface is clean and dry. The glue is good. Most ever on a single tube that I can recall was about 12 patches on my city bike. That was before kevlar belted tires. Slime works... until you get a big hole, then you have a helluva mess to clean up and you WON'T want do be doing that on the side of the road. Been there, done that and WILL NOT use it ever it again. Bell tubes are made by Kenda, quality is okay. I usually spring for the Schwalbe tubes, cost several times more, but seem to last longer and hold air longer. YMMV.

Aaron