80 SG frame/81SH frame comparison

[John]

Is anybody aware of any significant differences between the two? I have been to Yama Mama's parts catalog and I see that the part number prefix is different. I realize that simply adding a small bracket can change a part number prefix, but it should be basically the same frame, one would think. I may have to replace the frame on my 80, and I haven't seen too many available in my area, and if I should happen upon an 81 frame, should I buy it? Restoring a frame may be easier than repairing one. Hell, I could even graft the steering head from the 80 onto the 81 frame, and that way my serial number won't change, and I won't have to go through the hassle of convincing the DMV that the mismatching of numbers doesn't mean the bike is stolen.

[DiverRay]

John;
The motor would mount the same, so that part of a transplant would be easy. The difference is probably in attatch points for some of the different "fixtures" on the newer bike. If you can find a "rolling chassis", it would probably be an easy transplant. I would think trying to fit all of your "stock" items would be harder to do.
Ray

[John]

I have eyeballed the two Specials, my 80 and 81, that are sitting right next to each other in the garage, and I really can't see any major differences. I do have a MIG welder in case I'd have to swap some brackets over from the 80 frame to an 81.

[lsippell]

John,

I got into it with a bent frame on a '79 750 triple back in 1981. It was a nightmare. It wasn't bent bad, just enought that it wouldn't track straight. 3 times I striped that bike down to the frame and straightened it till all measurments were spot on. And within a few weeks it would be back where it was before I straightened it. The third time I took it to where it was over diminsioned to allow for a lot of creep back, and it creeped back to the bent positioned. After that I got a new frame from Yamaha!

Louis

[TopCatGr58]

Hey John,

I know the 79SF's frame is different from the 81, the 81 grab rails don't line up with the mounting holes or the upper rear shock mount posts/bolts! After reviewing your two on the parts catalog, with the grab rail the same style between the 80-81, looks like it'll be a simple bolt on/over process!!
T.C.