Ordered some Shimano brake levers (my bike has downtube shifters) and I just recently retaped my handle bars in the past 2 to 3 weeks....when I install these new bike levers can I just reuse this bar tape or should I just buy new tape?

If it's the kind with the adhesive strip down the center, you may end up with some residue exposed when you rewrap. Just clean that off.

To me as long as it stays intact when you unwrap it, there's no reason not to reuse it unless you want different tape.

"Gel" bar tape uses a non adhesive tacky ness, on the back, I favor it.

lay a strip of old bar tape around the top corner, it helps ,
gap resistance and a bit of comfort.

Yeah, I'd agree that if it comes off in one piece, go ahead and reuse it.

I use new bartape. It's cheap enough.

More importantly to me, it's much less frustrating to wrap new tape than it is to try to match the old wrap lines and cable bulges.

Thanks guys for the info....I think based on info given might as well do a rewrap...inexspensive and less headache