You're not the only one to wonder. It obviously comes from the Latin suffragium -- a vote. Beyond that nobody knows for sure. See Smith's Dictionary of Antiquities:

The etymology is uncertain, for the opinions of those who connect it with fra/zesqai or fragor do not deserve notice. Wunder thinks that it may possibly be allied with suffrago, and signified originally an ankle-bone or knuckle-bone.

http://makeashorterlink.com/?N11F254E6

Bingley

Bingley