jackshaft

trackfodder

Member
Sep 8, 2008
347
2
18
As a device to go to sleep I have lately been building motorbike components in my mind. Last night I was thinking of a better way to mount a jackshaft. I would machine the ends of black pipe to accept sealed 16mm I.D. ball bearings. Then mill a portion of the O.D. to receive a flat plate of about 3/16" thickness with rounded corners wide enough to mount U-bolts to secure it to the seatpost above and below the tube. Then a dog-point setscrew or 2 into the frame to prevent the jackshaft unit rotating. Insetting the plate into the tube wall would look better and allow a nicer weld bead. I am still playing with the Lawnboy 4 HP in a Cranbrook frame idea. It might get my COMET VST. Just too cold to do squat right now.drn2
 

Amarion1

Member
Sep 15, 2012
99
2
8
33
Bellingham WA
How about welding it right into the seat tube?






I absolutely love this!! Never would have thought to do it like that. How are you going about making sure its straight? I may do this on a future build if my wife lets me do another one.. for extra support, where you weld the tubing to the housing. I would drill both top and bottom to the i.d. and tap in some solid rod. Then you can weld tubing to the outside and the rod to the inside of the shaft housing. Locks it all together beautifully then :-D
 

msrfan

Well-Known Member
Sep 17, 2010
1,799
95
48
Southern California
I've used this system once before and it works perfectly because I made a transition collar top and bottom to weld everything in place. I held it square with wood blocks and plywood while welding.