Frame differences

[ltcps]

Does anyone have any reference material that list the differences in the various year frames?

I see in some of the photos that some (newer?) frames have dog legged backbones and some like mine are straight.

The same thing goes for the vertical struts connecting the backbone to the lower part of the frame. Some of the verticals are about directly under the seat spring and even with the front edge of the rear wheel and some are quite a bit further back.

Are the  verticals really necessary? in installing a gx200 with a Comet CVT it will be necessary to remove them on mine. Sime no jackshaft is needed, should I add some further back?

Ideas?

[Ricks]

I think the verticles are only used to hold the transmission.  If they intended them to be chassis supports, I believe they would have used tube instead of flat stock.

I hadn't noticed the dog leg, good eye!  My 1949 is straight, but my 53 & 54 are dog legged.  Straight tubing on the 49 that is.  They do taper from the front to the rear and are about 6 1/2" wide at the outside of the tubing, behind the seat.  They continue to taper to the same 7 1/2" as the dog legged frames.  I wonder if they needed more room for the automatic transmission, therefore put the dog leg?  The dog leg is more elegant though, as the frame parallels the seat bar.