Prepare a boiling water canner and heat pint jars. Keep jars hot until ready to fill.
In a large pot, combine sugar, vinegar, water, and the cinnamon sticks. Tie cloves and allspice in a clean, thin, white cloth (or use a spice bag) and add to the pot.
Bring to a boil, then reduce heat, cover, and simmer about 30 minutes.
While the brine simmers, prepare the pears. Wash pears, peel, and remove all of the blossom end. Leave stems on if desired. Halve or quarter large pears. To prevent browning, hold peeled pears in an ascorbic acid solution while you work. Drain just before cooking.
Add drained pears to the hot syrup. Bring back to a boil, then reduce heat and simmer 20 to 25 minutes, until pears are heated through and becoming tender.
Pack hot pears into hot pint jars. Add one cinnamon stick per jar (from the simmer syrup).
Ladle boiling syrup over pears, leaving 1/2-inch headspace and ensuring pears are covered. Remove air bubbles, adjust headspace if needed, wipe rims, and apply lids fingertip tight.
Process pint jars in a boiling water canner for 20 minutes for pints, adjusting for altitude (see notes).
Turn off heat, remove canner lid, and let jars rest 5 minutes. Remove jars and cool 12 to 24 hours. Check seals, label, and store.