Sprocket mounting bolts

btfx said:

I'm wondering what the common setup is for the cheap engines people sell online. What diameter bolt I should use and if/where I need washers or lock washers.

I bought a 66/80cc kit online and didn't get any bolts for it. Went to a hardware store and bought three 1/4" x 1.5" nuts/bolts to hold it together while I put everything else on. I noticed the 5/16" bolts didn't quite fit through the sprocket and mount. I don't know if it's worse to wear the sprocket and mount by threading it with the bigger bolts or potentially loose mounting with smaller bolts, so I decided to ask here.

I couldn't find that detail in any of the places that sell the sprocket mounting set.

Click to expand...

'''The standard kit sprocket bolts are 6 mm 1.0.
so just use 1/4 20 bolts with lock washers and nylock nuts
are a good idea too.

If you have a coaster brake you can get flat head 1/4 20 bolts and
countersink the holes so the bolt heads are flush with the sprocket'''.

''I will add''

In a great many cases two set of holes will let you flip a sprocket and have counter sunk holes for both directions. However most folks mount their kit sprockets with the beveled side facing out for better tire clearance. Depending on frame clearance etc the sprocket can be run both ways.


Here is one tutorial on the kit sprocket and the rag joint for coaster brake set up.

http://motorbicycling.com/f30/coaster-brake-dust-cap-mod-1841.html

http://motorbicycling.com/f48/vid-perfect-sprocket-alignment-every-time-31480.html

If there are any questions please feel free to ask BTFX! There are no dumb questions here ever just questions you have not asked us yet. We all start from somewhere. Their are ton's of folks on this forum who love to help.