I've always thought that Bradford Pears trees smell like the inside of a bike tire - that stale, rubbery air. But, the internet disagrees. The internet says:

Bradford pears smell like rancid grease.
Bradford Pears smell like jism.
Bradford Pears smell like lobster bisque.
Bradford Pears smell like semen.
Bradford Pears smell like fish.
Bradford Pears smell like period blood.
Bradford Pears smell like a big, greasy wad of semen.
Bradford Pears smell like ass in the spring.
Bradford pears smell like an old vagina.
Bradford pears smell like shit.
Bradford pears smell like feces.
Bradford Pears smell like 'Headache' to me.
Bradford Pears smell like rotting meat.