We haven't heard back from the OP yet. Hopefully he didn't have a bad blowout.

One thing that did cause one of my tires to bump. I had a pretty big gash in the tire, so I decided to install one of those Park boots. It caused a nasty "bump". So, I cut the boot in half and put it back in, and it worked fine, up until it worked through the tube, got a hole wore through it, and eventually it disintegrated.

Also, make sure the wheel is true without significant hops.