This is the first post of a shifter kit. It is from Au. Not the US. Dated 03-04-2008, 01:02 AM
Ghost 0 is the third poster on the thread.
Search for "Nice Jackshaft Idea" by Moteredhobart on another channel.
Here is the original idea in finished form.
ZBox engine innovations 2008
From zbox site
Just got back and I've had a quick peek at the page and it looks good, hope it grows some more . I've attached a couple of pic's of the components for the counter shaft and freewheel chaingear. All of these pieces I machined up in my workshop. There a couple of differences between what is in the pictures and what actually went on the final installation but the concept is the same. The main ones are the original 20T sprocket which was made from the outer of a DICTA freewheel was replaced with a 21T all home manufactured sprocket to allow for correct chain adjustment. The crank assembly pictured was ok until I upped the compression, then kicking it over - the threaded part stripped (forgot to loctite it !!) so it went into the scrap bin, the freewheel portion of the assembly is made from a DICTA 14T BMX freewheel sprocket with the teeth machined off. The thread in these is 30mm x 1.0 pitch and as the crank is alloy it definitely needs to be loctited in position. The outer ring in the picture is a lot larger than the final one, this is a press fit on the freewheel component sandwiching the chain wheel (suitably bored out to a neat fit on the freewheel). The chain wheel is then welded to the ring (you could use small through bolts which could also hold the rear kit gear sprocket) to form the complete assembly. I did also tap a thread down through the retaining ring and put a small ball bearing and a grub screw in there to assure that the crank assembly doesn't slip on the freewheel. Feel free to edit this if you think it needs it, as it is a bit long winded.
It even has pictures.
LOOK at the bottom of the page.