Sturmey-Archer 3-speed tranny

I learned something from a bike-shop guy. I had not been getting all 3 speeds out of the rear wheel tranny I am using for a jackshaft. I broke the little shifter chain and lost it's adjustment sleeve. The guy told me the shift is 1/4" movement for 3 gears, or 1/2 " total. I inserted the new chain and found I was only getting 3./8", which left it in 2nd, or direct drive. Turns out is was a matter of how much axle stuck out on each side. I moved it over and SHAZAM ! It will now obtain 3rd. It is already a long-stepping gearing, so should be interesting. I may need a bigger rear sprocket to get it within reason, but the 6-1/2 HP is quite adequate in 2nd with GOBS of acceleration. Far from lugging. It is really amazing to get rid of the squawking with the rear bike caliper. All it took was little ell things on the shoes that bear against the frame so they can't cycle back and forth.
On another note, I am still thinking Lawnboy for a friction drive. Wonder if a hard-rubber boat trailer roller might make a good drivewheel. A swiveling motormount on the rear rack would allow clutching to start or peddle and swinging it would bring the driver in contact with the sidewall and also the back-up idler roller on the other side. I don't know if a sidewall would stand up to it. I do have some 2.75 motorcycle tires that might serve. The Chinagirl clutch lock button method might be good to keep it disengaged against a pretty stout spring. They are really light, start easily, last forever,. and with around 6 HP could be awesome.

My Lawnboy is an ancient Scamp model that I run on 32:1. It sits with fuel in it under my sailboat all winter and starts right up in the spring. However, I now use an electric drill with a socket to start it, I just don't want to over/under prime it. I just turn the tap on and spin it without priming.

The freewheel direction made it necessary to use a 2nd. jackshaft. Not a big deal as it is readily accessable in the fork it mounts in. I am going to try to install the pix but may not get to as they have been run before. (see "did a springer") If not, send me your email address to [email protected]. Alternatively I can do it in Motoredbikes.com. Sounds like you had a Cerriani fork like I used. I am toying with setting up a back-up tranny from a Shimano just in case. Once when my 55 yr old son was about 6 I built a crotch-rocket looking thing with a very modified Power Products from an Otasco lawnmower. It origionally had the smallest cylinder, bronze rod, and external fan cone. It was on a little go-kart made from 1/4" sch. 80 pipe and an English Ford headlamp for a gastank. Looked like a BUG kart but very small as he only weighed 19 lbs at 2-1/2 yrs old. He could carry a broadslide through milk cartons like a pro. He never dinged the coffee table with his peddle tractor so that was why I did it. I could pick it and him up and carry them onto the local micro/go kart track and give him a push start. Very soon cooked the rod and went to the largest cylinder that would fit the case, needle brg. rod and crank and cooling shroud from a light plant. Then it went to a minibike with hand truck wheels and a chrome dinette chair for exhaust in a home cookin' manifold, and the head was cut off and replaced with an 11:1 C.R. head and transfer passage stuffed, Allstate Puch piston carb, pyramid reed cage, raised port windows, etc. It would cackle real good. THEN the big deal. A 20" bike front fork in 1"I.D. 4130cr-mo tubing connected to a steering head with another 20" front fork. a plate hanging down to mount the motor in, 2 cut -down James 125 front fork legs for rear suspension, a rectangle of 1/2" EMT conduit hinged at the steering head to carry the seat and tank which I made from GRP on styrofoam bucks with water-soluable wall-sizing to protect it and an oil filler cap from a M/C and door-closer dead-end nuts to mount with cast in. The seat had a teardrop faring on it
The wheels were 20" balloon with motorized bicycle. spokes and the S-A- tranny with a peddle sprocket. A jackshaft welded behind the engine on the frame tube. A 1/2" cold roll footbar with kickstarter rubbers at the top of the rear fork. A compression release for throttle, no brakes. Knee-notch tank. Racey lookin lil toy. Anyhow it had a centrifugal clutch and twist-grip shift. If he missed a gear, the thing rapped up and then when it engaged I had more parts for the fruit jar. So far I haven't destroyed the tranny on the 4-stroke as I am more careful and it isn't so quick to rev. OK for pix see "3-speed 6-1/2 HP Monarch". I can send more with your address. P.S. The cap was opened and hole cut in tank glass, and a cup of thinner and then hot water made an empty tank. DONT EVER blow fg sanding partical dust of the skin. It went IN and also into the family laundry. My baby daughter sat in the tub in baking soda quite a bit as it got into diapers. Yes, we used cloth diapers in those days. A vacuum cleaner is the only way to go.