The 850 Commando Frame # Mystery by Dave Comeau - Jan 2001 Updated 25 Feb 2007
Italian frames are Metric w the small frame tubes 25 mm and backbone 60 mm.
British frames are Imperial w small frame tubes 1 inch and backbone 2 1/4".
*Starting in May 1975, It appears the VIN was adopted to complete the frame#
1. VIN- the traditional Norton VIN number on the aluminum plate, engine and transmission # should be the same.
2. MFG date stamped on the plate.
3. Frame Batch Sequence number #850#F ........ #
4. Rear frame loop width, measured between the frame rail tubes 4" forward of the rear of the rear frame loop.
Normal 6 - 3/4" (will accept fastback tailsection) OR wide 7 - 3/8 inch
5. Letter size as stamped on the aluminum plate and frame batch sequence #
Small 5/32" or big 1/4"(like on engine).
6. Dash or No Dash in the frame part no. located on the front of the Left Front Tank mount, between the 06 and the 4140 (73), 5404 (74)
and 5632 (75E-Start) (Look on the braketet where coils are attached to frame)
7. The aluminum VIN plate is mounted more to the Left or Right side of the frame neck.
8. The coil bracket mount hole on the tank mount are Round or short "slots" with a rounded front and rear ends.
I like pigs. Dogs look up to us. Cats look down on us. Pigs treat us as equals. - Winston Churchill (Thom)