Jack Shaft

Here is my rough arsed "engineering " drawing of the jack shaft along with the bearings and sprockets, since im haveing the jack shaft i decided to make it do 2 jobs and have 2 stage gearing which means i can drop the rear sprocket from 46t to 36t with a saveing in unsprung weight and lowering the chain line, im also useing a 28mm R1 rear spindel saveing a further 400g of unsprung mass.

Here im useing a dial gauge to center the block of alluminum this is esential since i will have to turn it round to machine the other side, with out the dial gauge the bearings wouldnt line up.

And finaly ive bored it out to 35mm to fit the needle rollers im then going to bore both ends out to 42mm for the ballrace and then drill it for the sprocket drives then cut it in half and turn down sholders for the sprockets.