Jackshaft construction like this one?

S

Soquel Flyer

New Member
Jackshaft - Wondering if there is a modern equivialant available or best way to build one?

Two chains makes adjustment interesting? Freewheel is obviously inportant.


06769u2.jpg
 
You can make a simple one like this using and engine mounting plate, U-bolts and a couple pillow blocks for fairly cheap. Just use a sprocket on the right side instead of the brake disc I am using (pictured).

 
The exact same starting point as your red bike pic ended up looking like this once I remounted the jackshaft to allow independent adjustment of the engine chain by sliding the mount.
I cut the jackshaft tube off the motor mount plate and hung it off two bolts welded to the tubing and a welded slotted jackshaft mount plate on the frame.




Easier to keep the chain slack correct now that the engine adjusts separately from the jackshaft, especially when new and running in when adjustment is needed quite often.
 
The jackshaft in that first picture is mounted on the crankset - here is another view of that:

viva2.jpg


Some of those Harley bikes had 3 chains, others had only two & a one way clutch in the crank hub.

Here is the equivalent on my belt primary bike:

GearChange1.jpg


The cranks mount on a 25mm shaft that runs in a pair of sealed ball bearings that are pressed in to the hanger bracket.

The reduction assembly has both driver & driven mounted to one sleeve, with a pair of sealed ball bearings pressed in to it. It is held on when the crank arm is mounted.

GearChange2.jpg


With it all together is looks much like an original machine:

TR6.jpg


B.
 
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