Motorcycle Repair: Chain size

Question
1963 honda c105 trail 55, needs a chain. The original is missing. I am interested in using the small sprocket. I need all pertinent information to aquire a chain please. If you have information on the large sprocket. That may also be helpful.....Thanks,AND KEEP SMILING

Answer
James,

Here are images of the rear sprocket options from Honda...

http://www.cmsnl.com/honda-ca105t-trail-55-1963-usa_model996/partslist/F++12.htm

http://www.cmsnl.com/honda-ca105t-trail-55-1963-usa_model996/partslist/F++09.htm for chain part numbers, but translating the OEM numbers to DID or RK parts shows the chain pitch to be 420 size. Length depends upon the front and rear sprocket choices. Stock length appears to be 100 links.

Bill Silver