A 116 spool is not the same size as a 120 spool. Here is a size comparison
Length of the spool: 116 - 2.856" - 72.5mm 120 - 2.580" - 65.5mm Width of the part where the film is wound 116 - 2.814" - 71.4mm 120 - 2.5" - 65.3mm Diameter of the end of the spool 116 - 1.25" - 31.7mm 120 - .95" - 21.4mm Diameter of the middle of the spool 116 - .465" - 11.8mm 120 - .45" - 11.4mm. The 120 spool i measured looks kinda suspicious... i think it may have come with a holga, so it may be different than other 120 spools. I made the measurements with a pair of dial calipers, so they should be pretty accurate. The image size on my ica folder (which takes 116 film) is 4.2" by 2.42" (10.6 by 6.1 cm.) Here is a picture of the two side by side: http://imagehost.auctionwatch.com/preview/jr/jryeo/116.jpg John
