Summercrisp pear tree
I haven't been able to find anything to the contrary. The Summercrisp Pear needs another pear to pollinate, but the Triploid pears will not work. The Ure is not a triploid, so it should be a pollinator for the Summercrisp.
You don't say how long you have had the Summercrisp, but it takes four to five years before they will bear fruit.