I have a nine speed quick neo. With a new chain and cassette installed by a bike mechanic. My chronic problem is chain jump under torque in ninth gear. Its mostly infrequent but irritating. Perhaps every quarter mile the chain will jump once. I’ve tweeked the high screw and barrel adjustments to no avail. On my stand it shifts back and forth just fine, but on the road it jumps. I don’t want to take it back to the shop and lose ten days waiting.