And here we have the design for the assembled rear carrier assembly, which will tie the frame, rear engine mounts and swingarm pivot all tI need to make sure that my new motor mounts keep the engine properly aligned with the frame; this is complicated because the engine is clearly but ever so slightly offset to the left in the frame. I also need to determine the drive chain offset from C/L, so I can machine the rear wheel sprocket carrier to match.
My solution is a hardware-store laser cross-hair level. I hung the frame and engine from the ceiling and aligned the laser down the centerline of the frame and along the very bottom edge of the crossmember tube I added. From there I’ve been able to determine the measurements I needed to within about a millimeter.
Just to record the numbers here for my own future reference:
|Engine offset in frame:||4 mm to left|
|Rear crankcase mounting boss width:||31 mm|
|Counter shaft sprocket centerline to crankcase centerline:||68 mm|
|Counter shaft sprocket centerline to vehicle centerline:||68+4=72 mm|
That last one is problematic, because the sprocket offset on the GS450T rear wheel is about 85 mm. That means I’ll have to have about a half inch machined off the face of the sprocket carrier. I was hoping to avoid that.