Plain Bob is a method more suited to even numbers of bells; the “long fifths” in Bob doubles happens because there is one bell left over from the dodging pair.

Grandsire is a method devised for ringing changes on odd numbers of bells, usually with a covering tenor on six or more bells.

Look at Grandsire doubles in your “Diagrams” book. The path of the treble, shown by a red line, is plain hunting. 2, also shown with a red line, plain hunts as well, following the treble; it is “coursing” the treble. (Also see page 5.) So Grandsire has two hunt bells. One of these is always the treble, but the extra bell “in the hunt” might be any one of the other bells; however, in the “Plain Course” (that is, until bobs or singles are called,) the “hunt bell” is always 2.

The rules for ringing the plain course of Grandsire are similar to Plain Bob, but:

• The bell that is turned from lead by the treble makes thirds place over the treble and the hunt bell, then hunts down leads again.
• Because thirds place is made instead of seconds place, the dodging is moved ‘up’ one place compared to Plain Bob, so the dodging is now in 4-5 instead of in 3-4.

For more information, please read the rest of the article (provided by bellringing.org – Resource Finder): Introducing Grandsire Doubles.

If you would like more help then the following articles are also useful: